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Subject[PATCH 4/6] staging: ramster: ramster-specific changes to zcache/tmem
Date
In tmem.[ch], new "repatriate" (provoke async get) and "localify" (handle
incoming data resulting from an async get) routines combine with a handful
of changes to existing pamops interfaces allow the generic tmem code
to support asynchronous operations. Also, a new tmem_xhandle struct
groups together key information that must be passed to remote tmem stores.

Zcache-main.c is augmented with a large amount of ramster-specific code
to handle remote operations and "foreign" pages on both ends of the
"remotify" protocol. New "foreign" pools are auto-created on demand.
A "selfshrinker" thread periodically repatriates remote persistent pages
when local memory conditions allow. For certain operations, a queue is
necessary to guarantee strict ordering as out-of-order puts/flushes can
cause strange race conditions. Pampd pointers now either point to local
memory OR describe a remote page; to allow the same 64-bits to describe
either, the LSB is used to differentiate. Some acrobatics must be performed
to ensure local memory is available to handle a remote persistent get,
or deal with the data directly anyway if the malloc failed. Lots
of ramster-specific statistics are available via sysfs.

Note: Some debug ifdefs left in for now.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
---
drivers/staging/ramster/Kconfig | 17 +-
drivers/staging/ramster/Makefile | 5 +-
drivers/staging/ramster/tmem.c | 115 ++-
drivers/staging/ramster/tmem.h | 46 +-
drivers/staging/ramster/zcache-main.c | 1776 ++++++++++++++++++++++++++++-----
5 files changed, 1677 insertions(+), 282 deletions(-)

diff --git a/drivers/staging/ramster/Kconfig b/drivers/staging/ramster/Kconfig
index 7fabcb2..3957b87 100644
--- a/drivers/staging/ramster/Kconfig
+++ b/drivers/staging/ramster/Kconfig
@@ -1,13 +1,14 @@
-config ZCACHE
- tristate "Dynamic compression of swap pages and clean pagecache pages"
- depends on CLEANCACHE || FRONTSWAP
+config RAMSTER
+ tristate "Cross-machine RAM capacity sharing, aka peer-to-peer tmem"
+ depends on (CLEANCACHE || FRONTSWAP) && CONFIGFS_FS && !OCFS2_FS && !ZCACHE && !HIGHMEM
select XVMALLOC
select LZO_COMPRESS
select LZO_DECOMPRESS
default n
help
- Zcache doubles RAM efficiency while providing a significant
- performance boosts on many workloads. Zcache uses lzo1x
- compression and an in-kernel implementation of transcendent
- memory to store clean page cache pages and swap in RAM,
- providing a noticeable reduction in disk I/O.
+ RAMster allows RAM on other machines in a cluster to be utilized
+ dynamically and symmetrically instead of swapping to a local swap
+ disk, thus improving performance on memory-constrained workloads
+ while minimizing total RAM across the cluster. RAMster, like
+ zcache, compresses swap pages into local RAM, but then remotifies
+ the compressed pages to another node in the RAMster cluster.
diff --git a/drivers/staging/ramster/Makefile b/drivers/staging/ramster/Makefile
index 60daa27..e6c4a2e 100644
--- a/drivers/staging/ramster/Makefile
+++ b/drivers/staging/ramster/Makefile
@@ -1,3 +1,2 @@
-zcache-y := zcache-main.o tmem.o
-
-obj-$(CONFIG_ZCACHE) += zcache.o
+obj-$(CONFIG_RAMSTER) += zcache-main.o tmem.o
+obj-$(CONFIG_RAMSTER) += ramster_o2net.o cluster/
diff --git a/drivers/staging/ramster/tmem.c b/drivers/staging/ramster/tmem.c
index 1ca66ea..8f2f689 100644
--- a/drivers/staging/ramster/tmem.c
+++ b/drivers/staging/ramster/tmem.c
@@ -27,6 +27,7 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
+#include <linux/delay.h>

#include "tmem.h"

@@ -316,7 +317,7 @@ static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
}

static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index,
- void *new_pampd)
+ void *new_pampd, bool no_free)
{
struct tmem_objnode **slot;
void *ret = NULL;
@@ -325,7 +326,9 @@ static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index,
if ((slot != NULL) && (*slot != NULL)) {
void *old_pampd = *(void **)slot;
*(void **)slot = new_pampd;
- (*tmem_pamops.free)(old_pampd, obj->pool, NULL, 0);
+ if (!no_free)
+ (*tmem_pamops.free)(old_pampd, obj->pool,
+ NULL, 0, false);
ret = new_pampd;
}
return ret;
@@ -481,7 +484,7 @@ static void tmem_objnode_node_destroy(struct tmem_obj *obj,
if (ht == 1) {
obj->pampd_count--;
(*tmem_pamops.free)(objnode->slots[i],
- obj->pool, NULL, 0);
+ obj->pool, NULL, 0, true);
objnode->slots[i] = NULL;
continue;
}
@@ -498,7 +501,8 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj)
return;
if (obj->objnode_tree_height == 0) {
obj->pampd_count--;
- (*tmem_pamops.free)(obj->objnode_tree_root, obj->pool, NULL, 0);
+ (*tmem_pamops.free)(obj->objnode_tree_root,
+ obj->pool, NULL, 0, true);
} else {
tmem_objnode_node_destroy(obj, obj->objnode_tree_root,
obj->objnode_tree_height);
@@ -529,7 +533,7 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj)
* always flushes for simplicity.
*/
int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
- char *data, size_t size, bool raw, bool ephemeral)
+ char *data, size_t size, bool raw, int ephemeral)
{
struct tmem_obj *obj = NULL, *objfound = NULL, *objnew = NULL;
void *pampd = NULL, *pampd_del = NULL;
@@ -545,7 +549,7 @@ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
/* if found, is a dup put, flush the old one */
pampd_del = tmem_pampd_delete_from_obj(obj, index);
BUG_ON(pampd_del != pampd);
- (*tmem_pamops.free)(pampd, pool, oidp, index);
+ (*tmem_pamops.free)(pampd, pool, oidp, index, true);
if (obj->pampd_count == 0) {
objnew = obj;
objfound = NULL;
@@ -576,7 +580,7 @@ delete_and_free:
(void)tmem_pampd_delete_from_obj(obj, index);
free:
if (pampd)
- (*tmem_pamops.free)(pampd, pool, NULL, 0);
+ (*tmem_pamops.free)(pampd, pool, NULL, 0, true);
if (objnew) {
tmem_obj_free(objnew, hb);
(*tmem_hostops.obj_free)(objnew, pool);
@@ -586,6 +590,65 @@ out:
return ret;
}

+void *tmem_localify_get_pampd(struct tmem_pool *pool, struct tmem_oid *oidp,
+ uint32_t index, struct tmem_obj **ret_obj,
+ void **saved_hb)
+{
+ struct tmem_hashbucket *hb;
+ struct tmem_obj *obj = NULL;
+ void *pampd = NULL;
+
+ hb = &pool->hashbucket[tmem_oid_hash(oidp)];
+ spin_lock(&hb->lock);
+ obj = tmem_obj_find(hb, oidp);
+ if (likely(obj != NULL))
+ pampd = tmem_pampd_lookup_in_obj(obj, index);
+ *ret_obj = obj;
+ *saved_hb = (void *)hb;
+ /* note, hashbucket remains locked */
+ return pampd;
+}
+
+void tmem_localify_finish(struct tmem_obj *obj, uint32_t index,
+ void *pampd, void *saved_hb, bool delete)
+{
+ struct tmem_hashbucket *hb = (struct tmem_hashbucket *)saved_hb;
+
+ BUG_ON(!spin_is_locked(&hb->lock));
+ if (pampd != NULL) {
+ BUG_ON(obj == NULL);
+ (void)tmem_pampd_replace_in_obj(obj, index, pampd, 1);
+ } else if (delete) {
+ BUG_ON(obj == NULL);
+ (void)tmem_pampd_delete_from_obj(obj, index);
+ }
+ spin_unlock(&hb->lock);
+}
+
+static int tmem_repatriate(void **ppampd, struct tmem_hashbucket *hb,
+ struct tmem_pool *pool, struct tmem_oid *oidp,
+ uint32_t index, bool free, char *data)
+{
+ void *old_pampd = *ppampd, *new_pampd = NULL;
+ bool intransit = false;
+ int ret = 0;
+
+
+ if (!is_ephemeral(pool))
+ new_pampd = (*tmem_pamops.repatriate_preload)(
+ old_pampd, pool, oidp, index, &intransit);
+ if (intransit)
+ ret = -EAGAIN;
+ else if (new_pampd != NULL)
+ *ppampd = new_pampd;
+ /* must release the hb->lock else repatriate can't sleep */
+ spin_unlock(&hb->lock);
+ if (!intransit)
+ ret = (*tmem_pamops.repatriate)(old_pampd, new_pampd, pool,
+ oidp, index, free, data);
+ return ret;
+}
+
/*
* "Get" a page, e.g. if one can be found, copy the tmem page with the
* matching handle from PAM space to the kernel. By tmem definition,
@@ -607,14 +670,36 @@ int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
int ret = -1;
struct tmem_hashbucket *hb;
bool free = (get_and_free == 1) || ((get_and_free == 0) && ephemeral);
- bool lock_held = false;
+ bool lock_held = 0;
+ void **ppampd;

+again:
hb = &pool->hashbucket[tmem_oid_hash(oidp)];
spin_lock(&hb->lock);
- lock_held = true;
+ lock_held = 1;
obj = tmem_obj_find(hb, oidp);
if (obj == NULL)
goto out;
+ ppampd = __tmem_pampd_lookup_in_obj(obj, index);
+ if (ppampd == NULL)
+ goto out;
+ if (tmem_pamops.is_remote(*ppampd)) {
+ ret = tmem_repatriate(ppampd, hb, pool, oidp,
+ index, free, data);
+ lock_held = 0; /* note hb->lock has been unlocked */
+ if (ret == -EAGAIN) {
+ /* rare I think, but should cond_resched()??? */
+ usleep_range(10, 1000);
+ goto again;
+ } else if (ret != 0) {
+ if (ret != -ENOENT)
+ pr_err("UNTESTED case in tmem_get, ret=%d\n",
+ ret);
+ ret = -1;
+ goto out;
+ }
+ goto out;
+ }
if (free)
pampd = tmem_pampd_delete_from_obj(obj, index);
else
@@ -628,10 +713,6 @@ int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
obj = NULL;
}
}
- if (tmem_pamops.is_remote(pampd)) {
- lock_held = false;
- spin_unlock(&hb->lock);
- }
if (free)
ret = (*tmem_pamops.get_data_and_free)(
data, size, raw, pampd, pool, oidp, index);
@@ -668,7 +749,7 @@ int tmem_flush_page(struct tmem_pool *pool,
pampd = tmem_pampd_delete_from_obj(obj, index);
if (pampd == NULL)
goto out;
- (*tmem_pamops.free)(pampd, pool, oidp, index);
+ (*tmem_pamops.free)(pampd, pool, oidp, index, true);
if (obj->pampd_count == 0) {
tmem_obj_free(obj, hb);
(*tmem_hostops.obj_free)(obj, pool);
@@ -682,8 +763,8 @@ out:

/*
* If a page in tmem matches the handle, replace the page so that any
- * subsequent "get" gets the new page. Returns 0 if
- * there was a page to replace, else returns -1.
+ * subsequent "get" gets the new page. Returns the new page if
+ * there was a page to replace, else returns NULL.
*/
int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp,
uint32_t index, void *new_pampd)
@@ -697,7 +778,7 @@ int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp,
obj = tmem_obj_find(hb, oidp);
if (obj == NULL)
goto out;
- new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd);
+ new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd, 0);
ret = (*tmem_pamops.replace_in_obj)(new_pampd, obj);
out:
spin_unlock(&hb->lock);
diff --git a/drivers/staging/ramster/tmem.h b/drivers/staging/ramster/tmem.h
index ed147c4..47f1918 100644
--- a/drivers/staging/ramster/tmem.h
+++ b/drivers/staging/ramster/tmem.h
@@ -9,7 +9,6 @@
#ifndef _TMEM_H_
#define _TMEM_H_

-#include <linux/types.h>
#include <linux/highmem.h>
#include <linux/hash.h>
#include <linux/atomic.h>
@@ -89,6 +88,31 @@ struct tmem_oid {
uint64_t oid[3];
};

+struct tmem_xhandle {
+ uint8_t client_id;
+ uint8_t xh_data_cksum;
+ uint16_t xh_data_size;
+ uint16_t pool_id;
+ struct tmem_oid oid;
+ uint32_t index;
+ void *extra;
+};
+
+static inline struct tmem_xhandle tmem_xhandle_fill(uint16_t client_id,
+ struct tmem_pool *pool,
+ struct tmem_oid *oidp,
+ uint32_t index)
+{
+ struct tmem_xhandle xh;
+ xh.client_id = client_id;
+ xh.xh_data_cksum = (uint8_t)-1;
+ xh.xh_data_size = (uint16_t)-1;
+ xh.pool_id = pool->pool_id;
+ xh.oid = *oidp;
+ xh.index = index;
+ return xh;
+}
+
static inline void tmem_oid_set_invalid(struct tmem_oid *oidp)
{
oidp->oid[0] = oidp->oid[1] = oidp->oid[2] = -1UL;
@@ -147,7 +171,11 @@ struct tmem_obj {
unsigned int objnode_tree_height;
unsigned long objnode_count;
long pampd_count;
- void *extra; /* for private use by pampd implementation */
+ /* for current design of ramster, all pages belonging to
+ * an object reside on the same remotenode and extra is
+ * used to record the number of the remotenode so a
+ * flush-object operation can specify it */
+ void *extra; /* for use by pampd implementation */
DECL_SENTINEL
};

@@ -174,9 +202,14 @@ struct tmem_pamops {
int (*get_data_and_free)(char *, size_t *, bool, void *,
struct tmem_pool *, struct tmem_oid *,
uint32_t);
- void (*free)(void *, struct tmem_pool *, struct tmem_oid *, uint32_t);
+ void (*free)(void *, struct tmem_pool *,
+ struct tmem_oid *, uint32_t, bool);
void (*free_obj)(struct tmem_pool *, struct tmem_obj *);
bool (*is_remote)(void *);
+ void *(*repatriate_preload)(void *, struct tmem_pool *,
+ struct tmem_oid *, uint32_t, bool *);
+ int (*repatriate)(void *, void *, struct tmem_pool *,
+ struct tmem_oid *, uint32_t, bool, void *);
void (*new_obj)(struct tmem_obj *);
int (*replace_in_obj)(void *, struct tmem_obj *);
};
@@ -193,11 +226,16 @@ extern void tmem_register_hostops(struct tmem_hostops *m);

/* core tmem accessor functions */
extern int tmem_put(struct tmem_pool *, struct tmem_oid *, uint32_t index,
- char *, size_t, bool, bool);
+ char *, size_t, bool, int);
extern int tmem_get(struct tmem_pool *, struct tmem_oid *, uint32_t index,
char *, size_t *, bool, int);
extern int tmem_replace(struct tmem_pool *, struct tmem_oid *, uint32_t index,
void *);
+extern void *tmem_localify_get_pampd(struct tmem_pool *, struct tmem_oid *,
+ uint32_t index, struct tmem_obj **,
+ void **);
+extern void tmem_localify_finish(struct tmem_obj *, uint32_t index,
+ void *, void *, bool);
extern int tmem_flush_page(struct tmem_pool *, struct tmem_oid *,
uint32_t index);
extern int tmem_flush_object(struct tmem_pool *, struct tmem_oid *);
diff --git a/drivers/staging/ramster/zcache-main.c b/drivers/staging/ramster/zcache-main.c
index 49c8791..851e94a 100644
--- a/drivers/staging/ramster/zcache-main.c
+++ b/drivers/staging/ramster/zcache-main.c
@@ -1,7 +1,7 @@
/*
* zcache.c
*
- * Copyright (c) 2010,2011, Dan Magenheimer, Oracle Corp.
+ * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp.
* Copyright (c) 2010,2011, Nitin Gupta
*
* Zcache provides an in-kernel "host implementation" for transcendent memory
@@ -17,6 +17,9 @@
*
* [1] For a definition of page-accessible memory (aka PAM), see:
* http://marc.info/?l=linux-mm&m=127811271605009
+ * RAMSTER TODO:
+ * - handle remotifying of buddied pages (see zbud_remotify_zbpg)
+ * - kernel boot params: nocleancache/nofrontswap don't always work?!?
*/

#include <linux/module.h>
@@ -30,11 +33,16 @@
#include <linux/atomic.h>
#include <linux/math64.h>
#include "tmem.h"
+#include "zcache.h"
+#include "ramster.h"
+#include "cluster/tcp.h"

#include "../zram/xvmalloc.h" /* if built in drivers/staging */

+#define RAMSTER_TESTING
+
#if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP))
-#error "zcache is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP"
+#error "ramster is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP"
#endif
#ifdef CONFIG_CLEANCACHE
#include <linux/cleancache.h>
@@ -43,6 +51,61 @@
#include <linux/frontswap.h>
#endif

+enum ramster_remotify_op {
+ RAMSTER_REMOTIFY_EPH_PUT,
+ RAMSTER_REMOTIFY_PERS_PUT,
+ RAMSTER_REMOTIFY_FLUSH_PAGE,
+ RAMSTER_REMOTIFY_FLUSH_OBJ,
+ RAMSTER_INTRANSIT_PERS
+};
+
+struct ramster_remotify_hdr {
+ enum ramster_remotify_op op;
+ struct list_head list;
+};
+
+#define ZBH_SENTINEL 0x43214321
+#define ZBPG_SENTINEL 0xdeadbeef
+
+#define ZBUD_MAX_BUDS 2
+
+struct zbud_hdr {
+ struct ramster_remotify_hdr rem_op;
+ uint16_t client_id;
+ uint16_t pool_id;
+ struct tmem_oid oid;
+ uint32_t index;
+ uint16_t size; /* compressed size in bytes, zero means unused */
+ DECL_SENTINEL
+};
+
+#define ZVH_SENTINEL 0x43214321
+static const int zv_max_page_size = (PAGE_SIZE / 8) * 7;
+
+struct zv_hdr {
+ struct ramster_remotify_hdr rem_op;
+ uint16_t client_id;
+ uint16_t pool_id;
+ struct tmem_oid oid;
+ uint32_t index;
+ DECL_SENTINEL
+};
+
+struct flushlist_node {
+ struct ramster_remotify_hdr rem_op;
+ struct tmem_xhandle xh;
+};
+
+union {
+ struct ramster_remotify_hdr rem_op;
+ struct zv_hdr zv;
+ struct zbud_hdr zbud;
+ struct flushlist_node flist;
+} remotify_list_node;
+
+static LIST_HEAD(zcache_rem_op_list);
+static DEFINE_SPINLOCK(zcache_rem_op_list_lock);
+
#if 0
/* this is more aggressive but may cause other problems? */
#define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN)
@@ -98,20 +161,6 @@ static inline bool is_local_client(struct zcache_client *cli)
* read or written unless the zbpg's lock is held.
*/

-#define ZBH_SENTINEL 0x43214321
-#define ZBPG_SENTINEL 0xdeadbeef
-
-#define ZBUD_MAX_BUDS 2
-
-struct zbud_hdr {
- uint16_t client_id;
- uint16_t pool_id;
- struct tmem_oid oid;
- uint32_t index;
- uint16_t size; /* compressed size in bytes, zero means unused */
- DECL_SENTINEL
-};
-
struct zbud_page {
struct list_head bud_list;
spinlock_t lock;
@@ -141,20 +190,43 @@ static unsigned long zcache_zbud_buddied_count;
/* protects the buddied list and all unbuddied lists */
static DEFINE_SPINLOCK(zbud_budlists_spinlock);

-static LIST_HEAD(zbpg_unused_list);
-static unsigned long zcache_zbpg_unused_list_count;
-
-/* protects the unused page list */
-static DEFINE_SPINLOCK(zbpg_unused_list_spinlock);
-
static atomic_t zcache_zbud_curr_raw_pages;
static atomic_t zcache_zbud_curr_zpages;
static unsigned long zcache_zbud_curr_zbytes;
static unsigned long zcache_zbud_cumul_zpages;
static unsigned long zcache_zbud_cumul_zbytes;
static unsigned long zcache_compress_poor;
+static unsigned long zcache_policy_percent_exceeded;
static unsigned long zcache_mean_compress_poor;

+/*
+ * RAMster counters
+ * - Remote pages are pages with a local pampd but the data is remote
+ * - Foreign pages are pages stored locally but belonging to another node
+ */
+static atomic_t ramster_remote_pers_pages = ATOMIC_INIT(0);
+static unsigned long ramster_pers_remotify_enable;
+static unsigned long ramster_eph_remotify_enable;
+static unsigned long ramster_eph_pages_remoted;
+static unsigned long ramster_eph_pages_remote_failed;
+static unsigned long ramster_pers_pages_remoted;
+static unsigned long ramster_pers_pages_remote_failed;
+static unsigned long ramster_pers_pages_remote_nomem;
+static unsigned long ramster_remote_objects_flushed;
+static unsigned long ramster_remote_object_flushes_failed;
+static unsigned long ramster_remote_pages_flushed;
+static unsigned long ramster_remote_page_flushes_failed;
+static unsigned long ramster_remote_eph_pages_succ_get;
+static unsigned long ramster_remote_pers_pages_succ_get;
+static unsigned long ramster_remote_eph_pages_unsucc_get;
+static unsigned long ramster_remote_pers_pages_unsucc_get;
+static atomic_t ramster_curr_flnode_count = ATOMIC_INIT(0);
+static unsigned long ramster_curr_flnode_count_max;
+static atomic_t ramster_foreign_eph_pampd_count = ATOMIC_INIT(0);
+static unsigned long ramster_foreign_eph_pampd_count_max;
+static atomic_t ramster_foreign_pers_pampd_count = ATOMIC_INIT(0);
+static unsigned long ramster_foreign_pers_pampd_count_max;
+
/* forward references */
static void *zcache_get_free_page(void);
static void zcache_free_page(void *p);
@@ -210,6 +282,29 @@ static char *zbud_data(struct zbud_hdr *zh, unsigned size)
return p;
}

+static void zbud_copy_from_pampd(char *data, size_t *size, struct zbud_hdr *zh)
+{
+ struct zbud_page *zbpg;
+ char *p;
+ unsigned budnum;
+
+ ASSERT_SENTINEL(zh, ZBH);
+ budnum = zbud_budnum(zh);
+ zbpg = container_of(zh, struct zbud_page, buddy[budnum]);
+ spin_lock(&zbpg->lock);
+ BUG_ON(zh->size > *size);
+ p = (char *)zbpg;
+ if (budnum == 0)
+ p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) &
+ CHUNK_MASK);
+ else if (budnum == 1)
+ p += PAGE_SIZE - ((zh->size + CHUNK_SIZE - 1) & CHUNK_MASK);
+ /* client should be filled in by caller */
+ memcpy(data, p, zh->size);
+ *size = zh->size;
+ spin_unlock(&zbpg->lock);
+}
+
/*
* zbud raw page management
*/
@@ -218,38 +313,17 @@ static struct zbud_page *zbud_alloc_raw_page(void)
{
struct zbud_page *zbpg = NULL;
struct zbud_hdr *zh0, *zh1;
- bool recycled = 0;
-
- /* if any pages on the zbpg list, use one */
- spin_lock(&zbpg_unused_list_spinlock);
- if (!list_empty(&zbpg_unused_list)) {
- zbpg = list_first_entry(&zbpg_unused_list,
- struct zbud_page, bud_list);
- list_del_init(&zbpg->bud_list);
- zcache_zbpg_unused_list_count--;
- recycled = 1;
- }
- spin_unlock(&zbpg_unused_list_spinlock);
- if (zbpg == NULL)
- /* none on zbpg list, try to get a kernel page */
zbpg = zcache_get_free_page();
if (likely(zbpg != NULL)) {
INIT_LIST_HEAD(&zbpg->bud_list);
zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1];
spin_lock_init(&zbpg->lock);
- if (recycled) {
- ASSERT_INVERTED_SENTINEL(zbpg, ZBPG);
- SET_SENTINEL(zbpg, ZBPG);
- BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid));
- BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid));
- } else {
- atomic_inc(&zcache_zbud_curr_raw_pages);
- INIT_LIST_HEAD(&zbpg->bud_list);
- SET_SENTINEL(zbpg, ZBPG);
- zh0->size = 0; zh1->size = 0;
- tmem_oid_set_invalid(&zh0->oid);
- tmem_oid_set_invalid(&zh1->oid);
- }
+ atomic_inc(&zcache_zbud_curr_raw_pages);
+ INIT_LIST_HEAD(&zbpg->bud_list);
+ SET_SENTINEL(zbpg, ZBPG);
+ zh0->size = 0; zh1->size = 0;
+ tmem_oid_set_invalid(&zh0->oid);
+ tmem_oid_set_invalid(&zh1->oid);
}
return zbpg;
}
@@ -265,10 +339,8 @@ static void zbud_free_raw_page(struct zbud_page *zbpg)
BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid));
INVERT_SENTINEL(zbpg, ZBPG);
spin_unlock(&zbpg->lock);
- spin_lock(&zbpg_unused_list_spinlock);
- list_add(&zbpg->bud_list, &zbpg_unused_list);
- zcache_zbpg_unused_list_count++;
- spin_unlock(&zbpg_unused_list_spinlock);
+ atomic_dec(&zcache_zbud_curr_raw_pages);
+ zcache_free_page(zbpg);
}

/*
@@ -299,6 +371,10 @@ static void zbud_free_and_delist(struct zbud_hdr *zh)
struct zbud_page *zbpg =
container_of(zh, struct zbud_page, buddy[budnum]);

+ /* FIXME, should be BUG_ON, pool destruction path doesn't disable
+ * interrupts tmem_destroy_pool()->tmem_pampd_destroy_all_in_obj()->
+ * tmem_objnode_node_destroy()-> zcache_pampd_free() */
+ WARN_ON(!irqs_disabled());
spin_lock(&zbpg->lock);
if (list_empty(&zbpg->bud_list)) {
/* ignore zombie page... see zbud_evict_pages() */
@@ -358,8 +434,8 @@ static struct zbud_hdr *zbud_create(uint16_t client_id, uint16_t pool_id,
if (unlikely(zbpg == NULL))
goto out;
/* ok, have a page, now compress the data before taking locks */
- spin_lock(&zbpg->lock);
spin_lock(&zbud_budlists_spinlock);
+ spin_lock(&zbpg->lock);
list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list);
zbud_unbuddied[nchunks].count++;
zh = &zbpg->buddy[0];
@@ -389,12 +465,10 @@ init_zh:
zh->oid = *oid;
zh->pool_id = pool_id;
zh->client_id = client_id;
- /* can wait to copy the data until the list locks are dropped */
- spin_unlock(&zbud_budlists_spinlock);
-
to = zbud_data(zh, size);
memcpy(to, cdata, size);
spin_unlock(&zbpg->lock);
+ spin_unlock(&zbud_budlists_spinlock);
zbud_cumul_chunk_counts[nchunks]++;
atomic_inc(&zcache_zbud_curr_zpages);
zcache_zbud_cumul_zpages++;
@@ -458,9 +532,9 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg)
uint32_t index[ZBUD_MAX_BUDS];
struct tmem_oid oid[ZBUD_MAX_BUDS];
struct tmem_pool *pool;
+ unsigned long flags;

ASSERT_SPINLOCK(&zbpg->lock);
- BUG_ON(!list_empty(&zbpg->bud_list));
for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) {
zh = &zbpg->buddy[i];
if (zh->size) {
@@ -469,20 +543,18 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg)
oid[j] = zh->oid;
index[j] = zh->index;
j++;
- zbud_free(zh);
}
}
spin_unlock(&zbpg->lock);
for (i = 0; i < j; i++) {
pool = zcache_get_pool_by_id(client_id[i], pool_id[i]);
- if (pool != NULL) {
- tmem_flush_page(pool, &oid[i], index[i]);
- zcache_put_pool(pool);
- }
+ BUG_ON(pool == NULL);
+ local_irq_save(flags);
+ /* these flushes should dispose of any local storage */
+ tmem_flush_page(pool, &oid[i], index[i]);
+ local_irq_restore(flags);
+ zcache_put_pool(pool);
}
- ASSERT_SENTINEL(zbpg, ZBPG);
- spin_lock(&zbpg->lock);
- zbud_free_raw_page(zbpg);
}

/*
@@ -496,26 +568,8 @@ static void zbud_evict_zbpg(struct zbud_page *zbpg)
static void zbud_evict_pages(int nr)
{
struct zbud_page *zbpg;
- int i;
+ int i, newly_unused_pages = 0;

- /* first try freeing any pages on unused list */
-retry_unused_list:
- spin_lock_bh(&zbpg_unused_list_spinlock);
- if (!list_empty(&zbpg_unused_list)) {
- /* can't walk list here, since it may change when unlocked */
- zbpg = list_first_entry(&zbpg_unused_list,
- struct zbud_page, bud_list);
- list_del_init(&zbpg->bud_list);
- zcache_zbpg_unused_list_count--;
- atomic_dec(&zcache_zbud_curr_raw_pages);
- spin_unlock_bh(&zbpg_unused_list_spinlock);
- zcache_free_page(zbpg);
- zcache_evicted_raw_pages++;
- if (--nr <= 0)
- goto out;
- goto retry_unused_list;
- }
- spin_unlock_bh(&zbpg_unused_list_spinlock);

/* now try freeing unbuddied pages, starting with least space avail */
for (i = 0; i < MAX_CHUNK; i++) {
@@ -528,15 +582,15 @@ retry_unbud_list_i:
list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) {
if (unlikely(!spin_trylock(&zbpg->lock)))
continue;
- list_del_init(&zbpg->bud_list);
zbud_unbuddied[i].count--;
spin_unlock(&zbud_budlists_spinlock);
zcache_evicted_unbuddied_pages++;
/* want budlists unlocked when doing zbpg eviction */
zbud_evict_zbpg(zbpg);
+ newly_unused_pages++;
local_bh_enable();
if (--nr <= 0)
- goto out;
+ goto evict_unused;
goto retry_unbud_list_i;
}
spin_unlock_bh(&zbud_budlists_spinlock);
@@ -547,27 +601,406 @@ retry_bud_list:
spin_lock_bh(&zbud_budlists_spinlock);
if (list_empty(&zbud_buddied_list)) {
spin_unlock_bh(&zbud_budlists_spinlock);
- goto out;
+ goto evict_unused;
}
list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) {
if (unlikely(!spin_trylock(&zbpg->lock)))
continue;
- list_del_init(&zbpg->bud_list);
zcache_zbud_buddied_count--;
spin_unlock(&zbud_budlists_spinlock);
zcache_evicted_buddied_pages++;
/* want budlists unlocked when doing zbpg eviction */
zbud_evict_zbpg(zbpg);
+ newly_unused_pages++;
local_bh_enable();
if (--nr <= 0)
- goto out;
+ goto evict_unused;
goto retry_bud_list;
}
spin_unlock_bh(&zbud_budlists_spinlock);
+
+evict_unused:
+ return;
+}
+
+static DEFINE_PER_CPU(unsigned char *, zcache_remoteputmem);
+
+static int zbud_remotify_zbud(struct tmem_xhandle *xh, char *data,
+ size_t size)
+{
+ struct tmem_pool *pool;
+ int i, remotenode, ret = -1;
+ unsigned char cksum, *p;
+ unsigned long flags;
+
+ for (p = data, cksum = 0, i = 0; i < size; i++)
+ cksum += *p;
+ ret = ramster_remote_put(xh, data, size, true, &remotenode);
+ if (ret == 0) {
+ /* data was successfully remoted so change the local version
+ * to point to the remote node where it landed */
+ pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh->pool_id);
+ BUG_ON(pool == NULL);
+ local_irq_save(flags);
+ /* tmem_replace will also free up any local space */
+ (void)tmem_replace(pool, &xh->oid, xh->index,
+ pampd_make_remote(remotenode, size, cksum));
+ local_irq_restore(flags);
+ zcache_put_pool(pool);
+ ramster_eph_pages_remoted++;
+ ret = 0;
+ } else
+ ramster_eph_pages_remote_failed++;
+ return ret;
+}
+
+static int zbud_remotify_zbpg(struct zbud_page *zbpg)
+{
+ struct zbud_hdr *zh1, *zh2 = NULL;
+ struct tmem_xhandle xh1, xh2 = { 0 };
+ char *data1 = NULL, *data2 = NULL;
+ size_t size1 = 0, size2 = 0;
+ int ret = 0;
+ unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem);
+
+ ASSERT_SPINLOCK(&zbpg->lock);
+ if (zbpg->buddy[0].size == 0)
+ zh1 = &zbpg->buddy[1];
+ else if (zbpg->buddy[1].size == 0)
+ zh1 = &zbpg->buddy[0];
+ else {
+ zh1 = &zbpg->buddy[0];
+ zh2 = &zbpg->buddy[1];
+ }
+ /* don't remotify pages that are already remotified */
+ if (zh1->client_id != LOCAL_CLIENT)
+ zh1 = NULL;
+ if ((zh2 != NULL) && (zh2->client_id != LOCAL_CLIENT))
+ zh2 = NULL;
+
+ /* copy the data and metadata so can release lock */
+ if (zh1 != NULL) {
+ xh1.client_id = zh1->client_id;
+ xh1.pool_id = zh1->pool_id;
+ xh1.oid = zh1->oid;
+ xh1.index = zh1->index;
+ size1 = zh1->size;
+ data1 = zbud_data(zh1, size1);
+ memcpy(tmpmem, zbud_data(zh1, size1), size1);
+ data1 = tmpmem;
+ tmpmem += size1;
+ }
+ if (zh2 != NULL) {
+ xh2.client_id = zh2->client_id;
+ xh2.pool_id = zh2->pool_id;
+ xh2.oid = zh2->oid;
+ xh2.index = zh2->index;
+ size2 = zh2->size;
+ memcpy(tmpmem, zbud_data(zh2, size2), size2);
+ data2 = tmpmem;
+ }
+ spin_unlock(&zbpg->lock);
+ preempt_enable();
+
+ /* OK, no locks held anymore, remotify one or both zbuds */
+ if (zh1 != NULL)
+ ret = zbud_remotify_zbud(&xh1, data1, size1);
+ if (zh2 != NULL)
+ ret |= zbud_remotify_zbud(&xh2, data2, size2);
+ return ret;
+}
+
+void zbud_remotify_pages(int nr)
+{
+ struct zbud_page *zbpg;
+ int i, ret;
+
+ /*
+ * for now just try remotifying unbuddied pages, starting with
+ * least space avail
+ */
+ for (i = 0; i < MAX_CHUNK; i++) {
+retry_unbud_list_i:
+ preempt_disable(); /* enable in zbud_remotify_zbpg */
+ spin_lock_bh(&zbud_budlists_spinlock);
+ if (list_empty(&zbud_unbuddied[i].list)) {
+ spin_unlock_bh(&zbud_budlists_spinlock);
+ preempt_enable();
+ continue; /* next i in for loop */
+ }
+ list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) {
+ if (unlikely(!spin_trylock(&zbpg->lock)))
+ continue; /* next list_for_each_entry */
+ zbud_unbuddied[i].count--;
+ /* want budlists unlocked when doing zbpg remotify */
+ spin_unlock_bh(&zbud_budlists_spinlock);
+ ret = zbud_remotify_zbpg(zbpg);
+ /* preemption is re-enabled in zbud_remotify_zbpg */
+ if (ret == 0) {
+ if (--nr <= 0)
+ goto out;
+ goto retry_unbud_list_i;
+ }
+ /* if fail to remotify any page, quit */
+ pr_err("TESTING zbud_remotify_pages failed on page,"
+ " trying to re-add\n");
+ spin_lock_bh(&zbud_budlists_spinlock);
+ spin_lock(&zbpg->lock);
+ list_add_tail(&zbpg->bud_list, &zbud_unbuddied[i].list);
+ zbud_unbuddied[i].count++;
+ spin_unlock(&zbpg->lock);
+ spin_unlock_bh(&zbud_budlists_spinlock);
+ pr_err("TESTING zbud_remotify_pages failed on page,"
+ " finished re-add\n");
+ goto out;
+ }
+ spin_unlock_bh(&zbud_budlists_spinlock);
+ preempt_enable();
+ }
+
+next_buddied_zbpg:
+ preempt_disable(); /* enable in zbud_remotify_zbpg */
+ spin_lock_bh(&zbud_budlists_spinlock);
+ if (list_empty(&zbud_buddied_list))
+ goto unlock_out;
+ list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) {
+ if (unlikely(!spin_trylock(&zbpg->lock)))
+ continue; /* next list_for_each_entry */
+ zcache_zbud_buddied_count--;
+ /* want budlists unlocked when doing zbpg remotify */
+ spin_unlock_bh(&zbud_budlists_spinlock);
+ ret = zbud_remotify_zbpg(zbpg);
+ /* preemption is re-enabled in zbud_remotify_zbpg */
+ if (ret == 0) {
+ if (--nr <= 0)
+ goto out;
+ goto next_buddied_zbpg;
+ }
+ /* if fail to remotify any page, quit */
+ pr_err("TESTING zbud_remotify_pages failed on BUDDIED page,"
+ " trying to re-add\n");
+ spin_lock_bh(&zbud_budlists_spinlock);
+ spin_lock(&zbpg->lock);
+ list_add_tail(&zbpg->bud_list, &zbud_buddied_list);
+ zcache_zbud_buddied_count++;
+ spin_unlock(&zbpg->lock);
+ spin_unlock_bh(&zbud_budlists_spinlock);
+ pr_err("TESTING zbud_remotify_pages failed on BUDDIED page,"
+ " finished re-add\n");
+ goto out;
+ }
+unlock_out:
+ spin_unlock_bh(&zbud_budlists_spinlock);
+ preempt_enable();
out:
return;
}

+/* the "flush list" asynchronously collects pages to remotely flush */
+#define FLUSH_ENTIRE_OBJECT ((uint32_t)-1)
+static void ramster_flnode_free(struct flushlist_node *,
+ struct tmem_pool *);
+
+static void zcache_remote_flush_page(struct flushlist_node *flnode)
+{
+ struct tmem_xhandle *xh;
+ int remotenode, ret;
+
+ preempt_disable();
+ xh = &flnode->xh;
+ remotenode = flnode->xh.client_id;
+ ret = ramster_remote_flush(xh, remotenode);
+ if (ret >= 0)
+ ramster_remote_pages_flushed++;
+ else
+ ramster_remote_page_flushes_failed++;
+ preempt_enable_no_resched();
+ ramster_flnode_free(flnode, NULL);
+}
+
+static void zcache_remote_flush_object(struct flushlist_node *flnode)
+{
+ struct tmem_xhandle *xh;
+ int remotenode, ret;
+
+ preempt_disable();
+ xh = &flnode->xh;
+ remotenode = flnode->xh.client_id;
+ ret = ramster_remote_flush_object(xh, remotenode);
+ if (ret >= 0)
+ ramster_remote_objects_flushed++;
+ else
+ ramster_remote_object_flushes_failed++;
+ preempt_enable_no_resched();
+ ramster_flnode_free(flnode, NULL);
+}
+
+static void zcache_remote_eph_put(struct zbud_hdr *zbud)
+{
+ /* FIXME */
+}
+
+static void zcache_remote_pers_put(struct zv_hdr *zv)
+{
+ struct tmem_xhandle xh;
+ uint16_t size;
+ bool ephemeral;
+ int remotenode, ret = -1;
+ char *data;
+ struct tmem_pool *pool;
+ unsigned long flags;
+ unsigned char cksum;
+ char *p;
+ int i;
+ unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem);
+
+ ASSERT_SENTINEL(zv, ZVH);
+ BUG_ON(zv->client_id != LOCAL_CLIENT);
+ local_bh_disable();
+ xh.client_id = zv->client_id;
+ xh.pool_id = zv->pool_id;
+ xh.oid = zv->oid;
+ xh.index = zv->index;
+ size = xv_get_object_size(zv) - sizeof(*zv);
+ BUG_ON(size == 0 || size > zv_max_page_size);
+ data = (char *)zv + sizeof(*zv);
+ for (p = data, cksum = 0, i = 0; i < size; i++)
+ cksum += *p;
+ memcpy(tmpmem, data, size);
+ data = tmpmem;
+ pool = zcache_get_pool_by_id(zv->client_id, zv->pool_id);
+ ephemeral = is_ephemeral(pool);
+ zcache_put_pool(pool);
+ /* now OK to release lock set in caller */
+ spin_unlock(&zcache_rem_op_list_lock);
+ local_bh_enable();
+ preempt_disable();
+ ret = ramster_remote_put(&xh, data, size, ephemeral, &remotenode);
+ preempt_enable_no_resched();
+ if (ret != 0) {
+ /*
+ * This is some form of a memory leak... if the remote put
+ * fails, there will never be another attempt to remotify
+ * this page. But since we've dropped the zv pointer,
+ * the page may have been freed or the data replaced
+ * so we can't just "put it back" in the remote op list.
+ * Even if we could, not sure where to put it in the list
+ * because there may be flushes that must be strictly
+ * ordered vs the put. So leave this as a FIXME for now.
+ * But count them so we know if it becomes a problem.
+ */
+ ramster_pers_pages_remote_failed++;
+ goto out;
+ } else
+ atomic_inc(&ramster_remote_pers_pages);
+ ramster_pers_pages_remoted++;
+ /*
+ * data was successfully remoted so change the local version to
+ * point to the remote node where it landed
+ */
+ local_bh_disable();
+ pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh.pool_id);
+ local_irq_save(flags);
+ (void)tmem_replace(pool, &xh.oid, xh.index,
+ pampd_make_remote(remotenode, size, cksum));
+ local_irq_restore(flags);
+ zcache_put_pool(pool);
+ local_bh_enable();
+out:
+ return;
+}
+
+static void zcache_do_remotify_ops(int nr)
+{
+ struct ramster_remotify_hdr *rem_op;
+ union remotify_list_node *u;
+
+ while (1) {
+ if (!nr)
+ goto out;
+ spin_lock(&zcache_rem_op_list_lock);
+ if (list_empty(&zcache_rem_op_list)) {
+ spin_unlock(&zcache_rem_op_list_lock);
+ goto out;
+ }
+ rem_op = list_first_entry(&zcache_rem_op_list,
+ struct ramster_remotify_hdr, list);
+ list_del_init(&rem_op->list);
+ if (rem_op->op != RAMSTER_REMOTIFY_PERS_PUT)
+ spin_unlock(&zcache_rem_op_list_lock);
+ u = (union remotify_list_node *)rem_op;
+ switch (rem_op->op) {
+ case RAMSTER_REMOTIFY_EPH_PUT:
+BUG();
+ zcache_remote_eph_put((struct zbud_hdr *)rem_op);
+ break;
+ case RAMSTER_REMOTIFY_PERS_PUT:
+ zcache_remote_pers_put((struct zv_hdr *)rem_op);
+ break;
+ case RAMSTER_REMOTIFY_FLUSH_PAGE:
+ zcache_remote_flush_page((struct flushlist_node *)u);
+ break;
+ case RAMSTER_REMOTIFY_FLUSH_OBJ:
+ zcache_remote_flush_object((struct flushlist_node *)u);
+ break;
+ default:
+ BUG();
+ }
+ }
+out:
+ return;
+}
+
+/*
+ * For now, just push over a few pages every few seconds to
+ * ensure that it basically works
+ */
+static struct workqueue_struct *ramster_remotify_workqueue;
+static void ramster_remotify_process(struct work_struct *work);
+static DECLARE_DELAYED_WORK(ramster_remotify_worker,
+ ramster_remotify_process);
+
+static void ramster_remotify_queue_delayed_work(unsigned long delay)
+{
+ if (!queue_delayed_work(ramster_remotify_workqueue,
+ &ramster_remotify_worker, delay))
+ pr_err("ramster_remotify: bad workqueue\n");
+}
+
+
+static int use_frontswap;
+static int use_cleancache;
+static void ramster_remotify_process(struct work_struct *work)
+{
+ static bool remotify_in_progress;
+
+ BUG_ON(irqs_disabled());
+ if (remotify_in_progress)
+ ramster_remotify_queue_delayed_work(HZ);
+ else {
+ remotify_in_progress = true;
+#ifdef CONFIG_CLEANCACHE
+ if (use_cleancache && ramster_eph_remotify_enable)
+ zbud_remotify_pages(5000); /* FIXME is this a good number? */
+#endif
+#ifdef CONFIG_FRONTSWAP
+ if (use_frontswap && ramster_pers_remotify_enable)
+ zcache_do_remotify_ops(500); /* FIXME is this a good number? */
+#endif
+ remotify_in_progress = false;
+ ramster_remotify_queue_delayed_work(HZ);
+ }
+}
+
+static void ramster_remotify_init(void)
+{
+ unsigned long n = 60UL;
+ ramster_remotify_workqueue =
+ create_singlethread_workqueue("ramster_remotify");
+ ramster_remotify_queue_delayed_work(n * HZ);
+}
+
+
static void zbud_init(void)
{
int i;
@@ -631,15 +1064,6 @@ static int zbud_show_cumul_chunk_counts(char *buf)
* necessary for decompression) immediately preceding the compressed data.
*/

-#define ZVH_SENTINEL 0x43214321
-
-struct zv_hdr {
- uint32_t pool_id;
- struct tmem_oid oid;
- uint32_t index;
- DECL_SENTINEL
-};
-
/* rudimentary policy limits */
/* total number of persistent pages may not exceed this percentage */
static unsigned int zv_page_count_policy_percent = 75;
@@ -655,10 +1079,11 @@ static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7;
*/
static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5;

-static unsigned long zv_curr_dist_counts[NCHUNKS];
-static unsigned long zv_cumul_dist_counts[NCHUNKS];
+static atomic_t zv_curr_dist_counts[NCHUNKS];
+static atomic_t zv_cumul_dist_counts[NCHUNKS];
+

-static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id,
+static struct zv_hdr *zv_create(struct zcache_client *cli, uint32_t pool_id,
struct tmem_oid *oid, uint32_t index,
void *cdata, unsigned clen)
{
@@ -671,23 +1096,61 @@ static struct zv_hdr *zv_create(struct xv_pool *xvpool, uint32_t pool_id,

BUG_ON(!irqs_disabled());
BUG_ON(chunks >= NCHUNKS);
- ret = xv_malloc(xvpool, alloc_size,
+ ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr),
&page, &offset, ZCACHE_GFP_MASK);
if (unlikely(ret))
goto out;
- zv_curr_dist_counts[chunks]++;
- zv_cumul_dist_counts[chunks]++;
+ atomic_inc(&zv_curr_dist_counts[chunks]);
+ atomic_inc(&zv_cumul_dist_counts[chunks]);
zv = kmap_atomic(page, KM_USER0) + offset;
zv->index = index;
zv->oid = *oid;
zv->pool_id = pool_id;
SET_SENTINEL(zv, ZVH);
+ INIT_LIST_HEAD(&zv->rem_op.list);
+ zv->client_id = get_client_id_from_client(cli);
+ zv->rem_op.op = RAMSTER_REMOTIFY_PERS_PUT;
+ if (zv->client_id == LOCAL_CLIENT) {
+ spin_lock(&zcache_rem_op_list_lock);
+ list_add_tail(&zv->rem_op.list, &zcache_rem_op_list);
+ spin_unlock(&zcache_rem_op_list_lock);
+ }
memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen);
kunmap_atomic(zv, KM_USER0);
out:
return zv;
}

+/* similar to zv_create, but just reserve space, no data yet */
+static struct zv_hdr *zv_alloc(struct tmem_pool *pool,
+ struct tmem_oid *oid, uint32_t index,
+ unsigned clen)
+{
+ struct zcache_client *cli = pool->client;
+ struct page *page;
+ struct zv_hdr *zv = NULL;
+ uint32_t offset;
+ int ret;
+
+ BUG_ON(!irqs_disabled());
+ BUG_ON(!is_local_client(pool->client));
+ ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr),
+ &page, &offset, ZCACHE_GFP_MASK);
+ if (unlikely(ret))
+ goto out;
+ zv = kmap_atomic(page, KM_USER0) + offset;
+ SET_SENTINEL(zv, ZVH);
+ INIT_LIST_HEAD(&zv->rem_op.list);
+ zv->client_id = LOCAL_CLIENT;
+ zv->rem_op.op = RAMSTER_INTRANSIT_PERS;
+ zv->index = index;
+ zv->oid = *oid;
+ zv->pool_id = pool->pool_id;
+ kunmap_atomic(zv, KM_USER0);
+out:
+ return zv;
+}
+
static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv)
{
unsigned long flags;
@@ -698,10 +1161,15 @@ static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv)

ASSERT_SENTINEL(zv, ZVH);
BUG_ON(chunks >= NCHUNKS);
- zv_curr_dist_counts[chunks]--;
+ atomic_dec(&zv_curr_dist_counts[chunks]);
size -= sizeof(*zv);
+ spin_lock(&zcache_rem_op_list_lock);
+ size = xv_get_object_size(zv) - sizeof(*zv);
BUG_ON(size == 0);
INVERT_SENTINEL(zv, ZVH);
+ if (!list_empty(&zv->rem_op.list))
+ list_del_init(&zv->rem_op.list);
+ spin_unlock(&zcache_rem_op_list_lock);
page = virt_to_page(zv);
offset = (unsigned long)zv & ~PAGE_MASK;
local_irq_save(flags);
@@ -727,6 +1195,29 @@ static void zv_decompress(struct page *page, struct zv_hdr *zv)
BUG_ON(clen != PAGE_SIZE);
}

+static void zv_copy_from_pampd(char *data, size_t *bufsize, struct zv_hdr *zv)
+{
+ unsigned size;
+
+ ASSERT_SENTINEL(zv, ZVH);
+ size = xv_get_object_size(zv) - sizeof(*zv);
+ BUG_ON(size == 0 || size > zv_max_page_size);
+ BUG_ON(size > *bufsize);
+ memcpy(data, (char *)zv + sizeof(*zv), size);
+ *bufsize = size;
+}
+
+static void zv_copy_to_pampd(struct zv_hdr *zv, char *data, size_t size)
+{
+ unsigned zv_size;
+
+ ASSERT_SENTINEL(zv, ZVH);
+ zv_size = xv_get_object_size(zv) - sizeof(*zv);
+ BUG_ON(zv_size != size);
+ BUG_ON(zv_size == 0 || zv_size > zv_max_page_size);
+ memcpy((char *)zv + sizeof(*zv), data, size);
+}
+
#ifdef CONFIG_SYSFS
/*
* show a distribution of compression stats for zv pages.
@@ -738,7 +1229,7 @@ static int zv_curr_dist_counts_show(char *buf)
char *p = buf;

for (i = 0; i < NCHUNKS; i++) {
- n = zv_curr_dist_counts[i];
+ n = atomic_read(&zv_curr_dist_counts[i]);
p += sprintf(p, "%lu ", n);
chunks += n;
sum_total_chunks += i * n;
@@ -754,7 +1245,7 @@ static int zv_cumul_dist_counts_show(char *buf)
char *p = buf;

for (i = 0; i < NCHUNKS; i++) {
- n = zv_cumul_dist_counts[i];
+ n = atomic_read(&zv_cumul_dist_counts[i]);
p += sprintf(p, "%lu ", n);
chunks += n;
sum_total_chunks += i * n;
@@ -890,6 +1381,7 @@ static unsigned long zcache_flush_found;
static unsigned long zcache_flobj_total;
static unsigned long zcache_flobj_found;
static unsigned long zcache_failed_eph_puts;
+static unsigned long zcache_nonactive_puts;
static unsigned long zcache_failed_pers_puts;

/*
@@ -970,6 +1462,7 @@ static unsigned long zcache_put_to_flush;
*/
static struct kmem_cache *zcache_objnode_cache;
static struct kmem_cache *zcache_obj_cache;
+static struct kmem_cache *ramster_flnode_cache;
static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0);
static unsigned long zcache_curr_obj_count_max;
static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0);
@@ -985,6 +1478,7 @@ struct zcache_preload {
struct tmem_obj *obj;
int nr;
struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH];
+ struct flushlist_node *flnode;
};
static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, };

@@ -993,6 +1487,7 @@ static int zcache_do_preload(struct tmem_pool *pool)
struct zcache_preload *kp;
struct tmem_objnode *objnode;
struct tmem_obj *obj;
+ struct flushlist_node *flnode;
void *page;
int ret = -ENOMEM;

@@ -1023,27 +1518,61 @@ static int zcache_do_preload(struct tmem_pool *pool)
zcache_failed_alloc++;
goto out;
}
- page = (void *)__get_free_page(ZCACHE_GFP_MASK);
- if (unlikely(page == NULL)) {
- zcache_failed_get_free_pages++;
- kmem_cache_free(zcache_obj_cache, obj);
+ flnode = kmem_cache_alloc(ramster_flnode_cache, ZCACHE_GFP_MASK);
+ if (unlikely(flnode == NULL)) {
+ zcache_failed_alloc++;
goto out;
}
+ if (is_ephemeral(pool)) {
+ page = (void *)__get_free_page(ZCACHE_GFP_MASK);
+ if (unlikely(page == NULL)) {
+ zcache_failed_get_free_pages++;
+ kmem_cache_free(zcache_obj_cache, obj);
+ kmem_cache_free(ramster_flnode_cache, flnode);
+ goto out;
+ }
+ }
preempt_disable();
kp = &__get_cpu_var(zcache_preloads);
if (kp->obj == NULL)
kp->obj = obj;
else
kmem_cache_free(zcache_obj_cache, obj);
- if (kp->page == NULL)
- kp->page = page;
+ if (kp->flnode == NULL)
+ kp->flnode = flnode;
else
- free_page((unsigned long)page);
+ kmem_cache_free(ramster_flnode_cache, flnode);
+ if (is_ephemeral(pool)) {
+ if (kp->page == NULL)
+ kp->page = page;
+ else
+ free_page((unsigned long)page);
+ }
ret = 0;
out:
return ret;
}

+static int ramster_do_preload_flnode_only(struct tmem_pool *pool)
+{
+ struct zcache_preload *kp;
+ struct flushlist_node *flnode;
+ int ret = -ENOMEM;
+
+ BUG_ON(!irqs_disabled());
+ if (unlikely(ramster_flnode_cache == NULL))
+ BUG();
+ kp = &__get_cpu_var(zcache_preloads);
+ flnode = kmem_cache_alloc(ramster_flnode_cache, GFP_ATOMIC);
+ if (unlikely(flnode == NULL) && kp->flnode == NULL)
+ BUG(); /* FIXME handle more gracefully, but how??? */
+ else if (kp->flnode == NULL)
+ kp->flnode = flnode;
+ else
+ kmem_cache_free(ramster_flnode_cache, flnode);
+ return ret;
+}
+
static void *zcache_get_free_page(void)
{
struct zcache_preload *kp;
@@ -1116,6 +1645,30 @@ static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool)
kmem_cache_free(zcache_obj_cache, obj);
}

+static struct flushlist_node *ramster_flnode_alloc(struct tmem_pool *pool)
+{
+ struct flushlist_node *flnode = NULL;
+ struct zcache_preload *kp;
+ int count;
+
+ kp = &__get_cpu_var(zcache_preloads);
+ flnode = kp->flnode;
+ BUG_ON(flnode == NULL);
+ kp->flnode = NULL;
+ count = atomic_inc_return(&ramster_curr_flnode_count);
+ if (count > ramster_curr_flnode_count_max)
+ ramster_curr_flnode_count_max = count;
+ return flnode;
+}
+
+static void ramster_flnode_free(struct flushlist_node *flnode,
+ struct tmem_pool *pool)
+{
+ atomic_dec(&ramster_curr_flnode_count);
+ BUG_ON(atomic_read(&ramster_curr_flnode_count) < 0);
+ kmem_cache_free(ramster_flnode_cache, flnode);
+}
+
static struct tmem_hostops zcache_hostops = {
.obj_alloc = zcache_obj_alloc,
.obj_free = zcache_obj_free,
@@ -1135,22 +1688,20 @@ static unsigned long zcache_curr_pers_pampd_count_max;
/* forward reference */
static int zcache_compress(struct page *from, void **out_va, size_t *out_len);

-static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
+static int zcache_pampd_eph_create(char *data, size_t size, bool raw,
struct tmem_pool *pool, struct tmem_oid *oid,
- uint32_t index)
+ uint32_t index, void **pampd)
{
- void *pampd = NULL, *cdata;
- size_t clen;
- int ret;
- unsigned long count;
- struct page *page = (struct page *)(data);
+ int ret = -1;
+ void *cdata = data;
+ size_t clen = size;
struct zcache_client *cli = pool->client;
uint16_t client_id = get_client_id_from_client(cli);
- unsigned long zv_mean_zsize;
- unsigned long curr_pers_pampd_count;
- u64 total_zsize;
+ struct page *page = NULL;
+ unsigned long count;

- if (eph) {
+ if (!raw) {
+ page = virt_to_page(data);
ret = zcache_compress(page, &cdata, &clen);
if (ret == 0)
goto out;
@@ -1158,46 +1709,114 @@ static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
zcache_compress_poor++;
goto out;
}
- pampd = (void *)zbud_create(client_id, pool->pool_id, oid,
- index, page, cdata, clen);
- if (pampd != NULL) {
- count = atomic_inc_return(&zcache_curr_eph_pampd_count);
- if (count > zcache_curr_eph_pampd_count_max)
- zcache_curr_eph_pampd_count_max = count;
- }
- } else {
- curr_pers_pampd_count =
- atomic_read(&zcache_curr_pers_pampd_count);
- if (curr_pers_pampd_count >
- (zv_page_count_policy_percent * totalram_pages) / 100)
- goto out;
- ret = zcache_compress(page, &cdata, &clen);
- if (ret == 0)
- goto out;
- /* reject if compression is too poor */
- if (clen > zv_max_zsize) {
- zcache_compress_poor++;
+ }
+ *pampd = (void *)zbud_create(client_id, pool->pool_id, oid,
+ index, page, cdata, clen);
+ if (*pampd == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = 0;
+ count = atomic_inc_return(&zcache_curr_eph_pampd_count);
+ if (count > zcache_curr_eph_pampd_count_max)
+ zcache_curr_eph_pampd_count_max = count;
+ if (client_id != LOCAL_CLIENT) {
+ count = atomic_inc_return(&ramster_foreign_eph_pampd_count);
+ if (count > ramster_foreign_eph_pampd_count_max)
+ ramster_foreign_eph_pampd_count_max = count;
+ }
+out:
+ return ret;
+}
+
+static int zcache_pampd_pers_create(char *data, size_t size, bool raw,
+ struct tmem_pool *pool, struct tmem_oid *oid,
+ uint32_t index, void **pampd)
+{
+ int ret = -1;
+ void *cdata = data;
+ size_t clen = size;
+ struct zcache_client *cli = pool->client;
+ struct page *page;
+ unsigned long count;
+ unsigned long zv_mean_zsize;
+ struct zv_hdr *zv;
+ long curr_pers_pampd_count;
+ u64 total_zsize;
+#ifdef RAMSTER_TESTING
+ static bool pampd_neg_warned;
+#endif
+
+ curr_pers_pampd_count = atomic_read(&zcache_curr_pers_pampd_count) -
+ atomic_read(&ramster_remote_pers_pages);
+#ifdef RAMSTER_TESTING
+ /* should always be positive, but warn if accounting is off */
+ if (!pampd_neg_warned) {
+ pr_warn("ramster: bad accounting for curr_pers_pampd_count\n");
+ pampd_neg_warned = true;
+ }
+#endif
+ if (curr_pers_pampd_count >
+ (zv_page_count_policy_percent * totalram_pages) / 100) {
+ zcache_policy_percent_exceeded++;
+ goto out;
+ }
+ if (raw)
+ goto ok_to_create;
+ page = virt_to_page(data);
+ if (zcache_compress(page, &cdata, &clen) == 0)
+ goto out;
+ /* reject if compression is too poor */
+ if (clen > zv_max_zsize) {
+ zcache_compress_poor++;
+ goto out;
+ }
+ /* reject if mean compression is too poor */
+ if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) {
+ total_zsize = xv_get_total_size_bytes(cli->xvpool);
+ zv_mean_zsize = div_u64(total_zsize, curr_pers_pampd_count);
+ if (zv_mean_zsize > zv_max_mean_zsize) {
+ zcache_mean_compress_poor++;
goto out;
}
- /* reject if mean compression is too poor */
- if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) {
- total_zsize = xv_get_total_size_bytes(cli->xvpool);
- zv_mean_zsize = div_u64(total_zsize,
- curr_pers_pampd_count);
- if (zv_mean_zsize > zv_max_mean_zsize) {
- zcache_mean_compress_poor++;
- goto out;
- }
- }
- pampd = (void *)zv_create(cli->xvpool, pool->pool_id,
- oid, index, cdata, clen);
- if (pampd == NULL)
- goto out;
- count = atomic_inc_return(&zcache_curr_pers_pampd_count);
- if (count > zcache_curr_pers_pampd_count_max)
- zcache_curr_pers_pampd_count_max = count;
}
+ok_to_create:
+ *pampd = (void *)zv_create(cli, pool->pool_id, oid, index, cdata, clen);
+ if (*pampd == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = 0;
+ count = atomic_inc_return(&zcache_curr_pers_pampd_count);
+ if (count > zcache_curr_pers_pampd_count_max)
+ zcache_curr_pers_pampd_count_max = count;
+ if (is_local_client(cli))
+ goto out;
+ zv = *(struct zv_hdr **)pampd;
+ count = atomic_inc_return(&ramster_foreign_pers_pampd_count);
+ if (count > ramster_foreign_pers_pampd_count_max)
+ ramster_foreign_pers_pampd_count_max = count;
out:
+ return ret;
+}
+
+static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
+ struct tmem_pool *pool, struct tmem_oid *oid,
+ uint32_t index)
+{
+ void *pampd = NULL;
+ int ret;
+ bool ephemeral;
+
+ BUG_ON(preemptible());
+ ephemeral = (eph == 1) || ((eph == 0) && is_ephemeral(pool));
+ if (ephemeral)
+ ret = zcache_pampd_eph_create(data, size, raw, pool,
+ oid, index, &pampd);
+ else
+ ret = zcache_pampd_pers_create(data, size, raw, pool,
+ oid, index, &pampd);
+ /* FIXME add some counters here for failed creates? */
return pampd;
}

@@ -1211,75 +1830,359 @@ static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw,
{
int ret = 0;

- BUG_ON(is_ephemeral(pool));
- zv_decompress((struct page *)(data), pampd);
+ BUG_ON(preemptible());
+ BUG_ON(is_ephemeral(pool)); /* Fix later for shared pools? */
+ BUG_ON(pampd_is_remote(pampd));
+ if (raw)
+ zv_copy_from_pampd(data, bufsize, pampd);
+ else
+ zv_decompress(virt_to_page(data), pampd);
return ret;
}

-/*
- * fill the pageframe corresponding to the struct page with the data
- * from the passed pampd
- */
static int zcache_pampd_get_data_and_free(char *data, size_t *bufsize, bool raw,
void *pampd, struct tmem_pool *pool,
struct tmem_oid *oid, uint32_t index)
{
int ret = 0;
+ unsigned long flags;
+ struct zcache_client *cli = pool->client;

- BUG_ON(!is_ephemeral(pool));
- zbud_decompress((struct page *)(data), pampd);
- zbud_free_and_delist((struct zbud_hdr *)pampd);
- atomic_dec(&zcache_curr_eph_pampd_count);
+ BUG_ON(preemptible());
+ BUG_ON(pampd_is_remote(pampd));
+ if (is_ephemeral(pool)) {
+ local_irq_save(flags);
+ if (raw)
+ zbud_copy_from_pampd(data, bufsize, pampd);
+ else
+ ret = zbud_decompress(virt_to_page(data), pampd);
+ zbud_free_and_delist((struct zbud_hdr *)pampd);
+ local_irq_restore(flags);
+ if (!is_local_client(cli)) {
+ atomic_dec(&ramster_foreign_eph_pampd_count);
+ WARN_ON_ONCE(atomic_read(&ramster_foreign_eph_pampd_count) < 0);
+ }
+ atomic_dec(&zcache_curr_eph_pampd_count);
+ WARN_ON_ONCE(atomic_read(&zcache_curr_eph_pampd_count) < 0);
+ } else {
+ if (is_local_client(cli))
+ BUG();
+ if (raw)
+ zv_copy_from_pampd(data, bufsize, pampd);
+ else
+ zv_decompress(virt_to_page(data), pampd);
+ zv_free(cli->xvpool, pampd);
+ if (!is_local_client(cli)) {
+ atomic_dec(&ramster_foreign_pers_pampd_count);
+ WARN_ON_ONCE(atomic_read(&ramster_foreign_pers_pampd_count) < 0);
+ }
+ atomic_dec(&zcache_curr_pers_pampd_count);
+ WARN_ON_ONCE(atomic_read(&zcache_curr_pers_pampd_count) < 0);
+ ret = 0;
+ }
return ret;
}

+static bool zcache_pampd_is_remote(void *pampd)
+{
+ return pampd_is_remote(pampd);
+}
+
/*
* free the pampd and remove it from any zcache lists
* pampd must no longer be pointed to from any tmem data structures!
*/
static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index)
+ struct tmem_oid *oid, uint32_t index, bool acct)
{
struct zcache_client *cli = pool->client;
-
- if (is_ephemeral(pool)) {
+ bool eph = is_ephemeral(pool);
+ struct zv_hdr *zv;
+
+ BUG_ON(preemptible());
+ if (pampd_is_remote(pampd)) {
+ WARN_ON(acct == false);
+ if (oid == NULL) {
+ /*
+ * a NULL oid means to ignore this pampd free
+ * as the remote freeing will be handled elsewhere
+ */
+ } else if (eph) {
+ /* FIXME remote flush optional but probably good idea */
+ /* FIXME get these working properly again */
+ atomic_dec(&zcache_curr_eph_pampd_count);
+ WARN_ON_ONCE(atomic_read(&zcache_curr_eph_pampd_count) < 0);
+ } else if (pampd_is_intransit(pampd)) {
+ /* did a pers remote get_and_free, so just free local */
+ pampd = pampd_mask_intransit_and_remote(pampd);
+ goto local_pers;
+ } else {
+ struct flushlist_node *flnode =
+ ramster_flnode_alloc(pool);
+
+ flnode->xh.client_id = pampd_remote_node(pampd);
+ flnode->xh.pool_id = pool->pool_id;
+ flnode->xh.oid = *oid;
+ flnode->xh.index = index;
+ flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_PAGE;
+ spin_lock(&zcache_rem_op_list_lock);
+ list_add(&flnode->rem_op.list, &zcache_rem_op_list);
+ spin_unlock(&zcache_rem_op_list_lock);
+ atomic_dec(&zcache_curr_pers_pampd_count);
+ WARN_ON_ONCE(atomic_read(&zcache_curr_pers_pampd_count) < 0);
+ atomic_dec(&ramster_remote_pers_pages);
+ WARN_ON_ONCE(atomic_read(&ramster_remote_pers_pages) < 0);
+ }
+ } else if (eph) {
zbud_free_and_delist((struct zbud_hdr *)pampd);
- atomic_dec(&zcache_curr_eph_pampd_count);
- BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0);
+ if (!is_local_client(pool->client)) {
+ atomic_dec(&ramster_foreign_eph_pampd_count);
+ WARN_ON_ONCE(atomic_read(&ramster_foreign_eph_pampd_count) < 0);
+ }
+ if (acct)
+ atomic_dec(&zcache_curr_eph_pampd_count);
+ /* FIXME get these working properly again */
+ WARN_ON_ONCE(atomic_read(&zcache_curr_eph_pampd_count) < 0);
} else {
- zv_free(cli->xvpool, (struct zv_hdr *)pampd);
- atomic_dec(&zcache_curr_pers_pampd_count);
- BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0);
+local_pers:
+ zv = (struct zv_hdr *)pampd;
+ if (!is_local_client(pool->client)) {
+ atomic_dec(&ramster_foreign_pers_pampd_count);
+ WARN_ON_ONCE(atomic_read(&ramster_foreign_pers_pampd_count) < 0);
+ }
+ zv_free(cli->xvpool, zv);
+ if (acct)
+ atomic_dec(&zcache_curr_pers_pampd_count);
+ /* FIXME get these working properly again */
+ WARN_ON_ONCE(atomic_read(&zcache_curr_pers_pampd_count) < 0);
}
}

-static void zcache_pampd_free_obj(struct tmem_pool *pool, struct tmem_obj *obj)
+static void zcache_pampd_free_obj(struct tmem_pool *pool,
+ struct tmem_obj *obj)
{
+ struct flushlist_node *flnode;
+
+ BUG_ON(preemptible());
+ if (obj->extra == NULL)
+ return;
+ BUG_ON(!pampd_is_remote(obj->extra));
+ flnode = ramster_flnode_alloc(pool);
+ flnode->xh.client_id = pampd_remote_node(obj->extra);
+ flnode->xh.pool_id = pool->pool_id;
+ flnode->xh.oid = obj->oid;
+ flnode->xh.index = FLUSH_ENTIRE_OBJECT;
+ flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_OBJ;
+ spin_lock(&zcache_rem_op_list_lock);
+ list_add(&flnode->rem_op.list, &zcache_rem_op_list);
+ spin_unlock(&zcache_rem_op_list_lock);
}

-static void zcache_pampd_new_obj(struct tmem_obj *obj)
+void zcache_pampd_new_obj(struct tmem_obj *obj)
{
+ obj->extra = NULL;
}

-static int zcache_pampd_replace_in_obj(void *pampd, struct tmem_obj *obj)
+int zcache_pampd_replace_in_obj(void *new_pampd, struct tmem_obj *obj)
{
- return -1;
+ int ret = -1;
+
+ if (new_pampd != NULL) {
+ if (obj->extra == NULL)
+ obj->extra = new_pampd;
+ /* enforce that all remote pages in an object reside
+ * in the same node! */
+ else if (pampd_remote_node(new_pampd) !=
+ pampd_remote_node((void *)(obj->extra)))
+ BUG();
+ ret = 0;
+ }
+ return ret;
}

-static bool zcache_pampd_is_remote(void *pampd)
+/*
+ * Called by the message handler after a (still compressed) page has been
+ * fetched from the remote machine in response to an "is_remote" tmem_get
+ * or persistent tmem_localify. For a tmem_get, "extra" is the address of
+ * the page that is to be filled to succesfully resolve the tmem_get; for
+ * a (persistent) tmem_localify, "extra" is NULL (as the data is placed only
+ * in the local zcache). "data" points to "size" bytes of (compressed) data
+ * passed in the message. In the case of a persistent remote get, if
+ * pre-allocation was successful (see zcache_repatriate_preload), the page
+ * is placed into both local zcache and at "extra".
+ */
+int zcache_localify(int pool_id, struct tmem_oid *oidp,
+ uint32_t index, char *data, size_t size,
+ void *extra)
{
- return 0;
+ int ret = -ENOENT;
+ unsigned long flags;
+ struct tmem_pool *pool;
+ bool ephemeral, delete = false;
+ size_t clen = PAGE_SIZE;
+ void *pampd, *saved_hb;
+ struct tmem_obj *obj;
+
+ pool = zcache_get_pool_by_id(LOCAL_CLIENT, pool_id);
+ if (unlikely(pool == NULL))
+ /* pool doesn't exist anymore */
+ goto out;
+ ephemeral = is_ephemeral(pool);
+ local_irq_save(flags); /* FIXME: maybe only disable softirqs? */
+ pampd = tmem_localify_get_pampd(pool, oidp, index, &obj, &saved_hb);
+ if (pampd == NULL) {
+ /* hmmm... must have been a flush while waiting */
+#ifdef RAMSTER_TESTING
+ pr_err("UNTESTED pampd==NULL in zcache_localify\n");
+#endif
+ if (ephemeral)
+ ramster_remote_eph_pages_unsucc_get++;
+ else
+ ramster_remote_pers_pages_unsucc_get++;
+ obj = NULL;
+ goto finish;
+ } else if (unlikely(!pampd_is_remote(pampd))) {
+ /* hmmm... must have been a dup put while waiting */
+#ifdef RAMSTER_TESTING
+ pr_err("UNTESTED dup while waiting in zcache_localify\n");
+#endif
+ if (ephemeral)
+ ramster_remote_eph_pages_unsucc_get++;
+ else
+ ramster_remote_pers_pages_unsucc_get++;
+ obj = NULL;
+ pampd = NULL;
+ ret = -EEXIST;
+ goto finish;
+ } else if (size == 0) {
+ /* no remote data, delete the local is_remote pampd */
+ pampd = NULL;
+ if (ephemeral)
+ ramster_remote_eph_pages_unsucc_get++;
+ else
+ BUG();
+ delete = true;
+ goto finish;
+ }
+ if (!ephemeral && pampd_is_intransit(pampd)) {
+ /* localify to zcache */
+ pampd = pampd_mask_intransit_and_remote(pampd);
+ zv_copy_to_pampd(pampd, data, size);
+ } else {
+ pampd = NULL;
+ obj = NULL;
+ }
+ if (extra != NULL) {
+ /* decompress direct-to-memory to complete remotify */
+ ret = lzo1x_decompress_safe((char *)data, size,
+ (char *)extra, &clen);
+ BUG_ON(ret != LZO_E_OK);
+ BUG_ON(clen != PAGE_SIZE);
+ }
+ if (ephemeral)
+ ramster_remote_eph_pages_succ_get++;
+ else
+ ramster_remote_pers_pages_succ_get++;
+ ret = 0;
+finish:
+ tmem_localify_finish(obj, index, pampd, saved_hb, delete);
+ zcache_put_pool(pool);
+ local_irq_restore(flags);
+out:
+ return ret;
+}
+
+/*
+ * Called on a remote persistent tmem_get to attempt to preallocate
+ * local storage for the data contained in the remote persistent page.
+ * If succesfully preallocated, returns the pampd, marked as remote and
+ * in_transit. Else returns NULL. Note that the appropriate tmem data
+ * structure must be locked.
+ */
+static void *zcache_pampd_repatriate_preload(void *pampd,
+ struct tmem_pool *pool,
+ struct tmem_oid *oid,
+ uint32_t index,
+ bool *intransit)
+{
+ int clen = pampd_remote_size(pampd);
+ void *ret_pampd = NULL;
+ unsigned long flags;
+
+ if (!pampd_is_remote(pampd))
+ BUG();
+ if (is_ephemeral(pool))
+ BUG();
+ if (pampd_is_intransit(pampd)) {
+ /*
+ * to avoid multiple allocations (and maybe a memory leak)
+ * don't preallocate if already in the process of being
+ * repatriated
+ */
+ *intransit = true;
+ goto out;
+ }
+ *intransit = false;
+ local_irq_save(flags);
+ ret_pampd = (void *)zv_alloc(pool, oid, index, clen);
+ if (ret_pampd != NULL) {
+ /*
+ * a pampd is marked intransit if it is remote and space has
+ * been allocated for it locally (note, only happens for
+ * persistent pages, in which case the remote copy is freed)
+ */
+ ret_pampd = pampd_mark_intransit(ret_pampd);
+ atomic_dec(&ramster_remote_pers_pages);
+ WARN_ON_ONCE(atomic_read(&ramster_remote_pers_pages) < 0);
+ } else
+ ramster_pers_pages_remote_nomem++;
+ local_irq_restore(flags);
+out:
+ return ret_pampd;
+}
+
+/*
+ * Called on a remote tmem_get to invoke a message to fetch the page.
+ * Might sleep so no tmem locks can be held. "extra" is passed
+ * all the way through the round-trip messaging to zcache_localify.
+ */
+static int zcache_pampd_repatriate(void *fake_pampd, void *real_pampd,
+ struct tmem_pool *pool,
+ struct tmem_oid *oid, uint32_t index,
+ bool free, void *extra)
+{
+ struct tmem_xhandle xh;
+ int ret;
+
+ if (pampd_is_intransit(real_pampd))
+ /* have local space pre-reserved, so free remote copy */
+ free = true;
+ xh = tmem_xhandle_fill(LOCAL_CLIENT, pool, oid, index);
+ /* unreliable request/response for now */
+ ret = ramster_remote_async_get(&xh, free,
+ pampd_remote_node(fake_pampd),
+ pampd_remote_size(fake_pampd),
+ pampd_remote_cksum(fake_pampd),
+ extra);
+#ifdef RAMSTER_TESTING
+ if (ret != 0 && ret != -ENOENT)
+ pr_err("TESTING zcache_pampd_repatriate returns, ret=%d\n",
+ ret);
+#endif
+ return ret;
}

static struct tmem_pamops zcache_pamops = {
.create = zcache_pampd_create,
.get_data = zcache_pampd_get_data,
- .get_data_and_free = zcache_pampd_get_data_and_free,
.free = zcache_pampd_free,
+ .get_data_and_free = zcache_pampd_get_data_and_free,
.free_obj = zcache_pampd_free_obj,
+ .is_remote = zcache_pampd_is_remote,
+ .repatriate_preload = zcache_pampd_repatriate_preload,
+ .repatriate = zcache_pampd_repatriate,
.new_obj = zcache_pampd_new_obj,
.replace_in_obj = zcache_pampd_replace_in_obj,
- .is_remote = zcache_pampd_is_remote,
};

/*
@@ -1327,9 +2230,13 @@ static int zcache_cpu_notifier(struct notifier_block *nb,
per_cpu(zcache_workmem, cpu) =
kzalloc(LZO1X_MEM_COMPRESS,
GFP_KERNEL | __GFP_REPEAT);
+ per_cpu(zcache_remoteputmem, cpu) =
+ kzalloc(PAGE_SIZE, GFP_KERNEL | __GFP_REPEAT);
break;
case CPU_DEAD:
case CPU_UP_CANCELED:
+ kfree(per_cpu(zcache_remoteputmem, cpu));
+ per_cpu(zcache_remoteputmem, cpu) = NULL;
free_pages((unsigned long)per_cpu(zcache_dstmem, cpu),
LZO_DSTMEM_PAGE_ORDER);
per_cpu(zcache_dstmem, cpu) = NULL;
@@ -1346,6 +2253,10 @@ static int zcache_cpu_notifier(struct notifier_block *nb,
kmem_cache_free(zcache_obj_cache, kp->obj);
kp->obj = NULL;
}
+ if (kp->flnode) {
+ kmem_cache_free(ramster_flnode_cache, kp->flnode);
+ kp->flnode = NULL;
+ }
if (kp->page) {
free_page((unsigned long)kp->page);
kp->page = NULL;
@@ -1402,12 +2313,12 @@ ZCACHE_SYSFS_RO(flush_found);
ZCACHE_SYSFS_RO(flobj_total);
ZCACHE_SYSFS_RO(flobj_found);
ZCACHE_SYSFS_RO(failed_eph_puts);
+ZCACHE_SYSFS_RO(nonactive_puts);
ZCACHE_SYSFS_RO(failed_pers_puts);
ZCACHE_SYSFS_RO(zbud_curr_zbytes);
ZCACHE_SYSFS_RO(zbud_cumul_zpages);
ZCACHE_SYSFS_RO(zbud_cumul_zbytes);
ZCACHE_SYSFS_RO(zbud_buddied_count);
-ZCACHE_SYSFS_RO(zbpg_unused_list_count);
ZCACHE_SYSFS_RO(evicted_raw_pages);
ZCACHE_SYSFS_RO(evicted_unbuddied_pages);
ZCACHE_SYSFS_RO(evicted_buddied_pages);
@@ -1416,6 +2327,7 @@ ZCACHE_SYSFS_RO(failed_alloc);
ZCACHE_SYSFS_RO(put_to_flush);
ZCACHE_SYSFS_RO(compress_poor);
ZCACHE_SYSFS_RO(mean_compress_poor);
+ZCACHE_SYSFS_RO(policy_percent_exceeded);
ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages);
ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages);
ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count);
@@ -1439,7 +2351,9 @@ static struct attribute *zcache_attrs[] = {
&zcache_flush_found_attr.attr,
&zcache_flobj_found_attr.attr,
&zcache_failed_eph_puts_attr.attr,
+ &zcache_nonactive_puts_attr.attr,
&zcache_failed_pers_puts_attr.attr,
+ &zcache_policy_percent_exceeded_attr.attr,
&zcache_compress_poor_attr.attr,
&zcache_mean_compress_poor_attr.attr,
&zcache_zbud_curr_raw_pages_attr.attr,
@@ -1448,7 +2362,6 @@ static struct attribute *zcache_attrs[] = {
&zcache_zbud_cumul_zpages_attr.attr,
&zcache_zbud_cumul_zbytes_attr.attr,
&zcache_zbud_buddied_count_attr.attr,
- &zcache_zbpg_unused_list_count_attr.attr,
&zcache_evicted_raw_pages_attr.attr,
&zcache_evicted_unbuddied_pages_attr.attr,
&zcache_evicted_buddied_pages_attr.attr,
@@ -1470,6 +2383,150 @@ static struct attribute_group zcache_attr_group = {
.name = "zcache",
};

+#define RAMSTER_SYSFS_RO(_name) \
+ static ssize_t ramster_##_name##_show(struct kobject *kobj, \
+ struct kobj_attribute *attr, char *buf) \
+ { \
+ return sprintf(buf, "%lu\n", ramster_##_name); \
+ } \
+ static struct kobj_attribute ramster_##_name##_attr = { \
+ .attr = { .name = __stringify(_name), .mode = 0444 }, \
+ .show = ramster_##_name##_show, \
+ }
+
+#define RAMSTER_SYSFS_RW(_name) \
+ static ssize_t ramster_##_name##_show(struct kobject *kobj, \
+ struct kobj_attribute *attr, char *buf) \
+ { \
+ return sprintf(buf, "%lu\n", ramster_##_name); \
+ } \
+ static ssize_t ramster_##_name##_store(struct kobject *kobj, \
+ struct kobj_attribute *attr, const char *buf, size_t count) \
+ { \
+ int err; \
+ unsigned long enable; \
+ err = strict_strtoul(buf, 10, &enable); \
+ if (err) \
+ return -EINVAL; \
+ ramster_##_name = enable; \
+ return count; \
+ } \
+ static struct kobj_attribute ramster_##_name##_attr = { \
+ .attr = { .name = __stringify(_name), .mode = 0644 }, \
+ .show = ramster_##_name##_show, \
+ .store = ramster_##_name##_store, \
+ }
+
+#define RAMSTER_SYSFS_RO_ATOMIC(_name) \
+ static ssize_t ramster_##_name##_show(struct kobject *kobj, \
+ struct kobj_attribute *attr, char *buf) \
+ { \
+ return sprintf(buf, "%d\n", atomic_read(&ramster_##_name)); \
+ } \
+ static struct kobj_attribute ramster_##_name##_attr = { \
+ .attr = { .name = __stringify(_name), .mode = 0444 }, \
+ .show = ramster_##_name##_show, \
+ }
+
+RAMSTER_SYSFS_RO_ATOMIC(remote_pers_pages);
+RAMSTER_SYSFS_RW(pers_remotify_enable);
+RAMSTER_SYSFS_RW(eph_remotify_enable);
+RAMSTER_SYSFS_RO(eph_pages_remoted);
+RAMSTER_SYSFS_RO(eph_pages_remote_failed);
+RAMSTER_SYSFS_RO(pers_pages_remoted);
+RAMSTER_SYSFS_RO(pers_pages_remote_failed);
+RAMSTER_SYSFS_RO(pers_pages_remote_nomem);
+RAMSTER_SYSFS_RO(remote_pages_flushed);
+RAMSTER_SYSFS_RO(remote_page_flushes_failed);
+RAMSTER_SYSFS_RO(remote_objects_flushed);
+RAMSTER_SYSFS_RO(remote_object_flushes_failed);
+RAMSTER_SYSFS_RO(remote_eph_pages_succ_get);
+RAMSTER_SYSFS_RO(remote_eph_pages_unsucc_get);
+RAMSTER_SYSFS_RO(remote_pers_pages_succ_get);
+RAMSTER_SYSFS_RO(remote_pers_pages_unsucc_get);
+RAMSTER_SYSFS_RO_ATOMIC(foreign_eph_pampd_count);
+RAMSTER_SYSFS_RO(foreign_eph_pampd_count_max);
+RAMSTER_SYSFS_RO_ATOMIC(foreign_pers_pampd_count);
+RAMSTER_SYSFS_RO(foreign_pers_pampd_count_max);
+RAMSTER_SYSFS_RO_ATOMIC(curr_flnode_count);
+RAMSTER_SYSFS_RO(curr_flnode_count_max);
+
+#define MANUAL_NODES 8
+static bool ramster_nodes_manual_up[MANUAL_NODES];
+static ssize_t ramster_manual_node_up_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int i;
+ char *p = buf;
+ for (i = 0; i < MANUAL_NODES; i++)
+ if (ramster_nodes_manual_up[i])
+ p += sprintf(p, "%d ", i);
+ p += sprintf(p, "\n");
+ return p - buf;
+}
+
+static ssize_t ramster_manual_node_up_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ int err;
+ unsigned long node_num;
+
+ err = strict_strtoul(buf, 10, &node_num);
+ if (err) {
+ pr_err("bad strtoul?\n");
+ return -EINVAL;
+ }
+ if (node_num >= MANUAL_NODES) {
+ pr_err("bad node_num=%lu?\n", node_num);
+ return -EINVAL;
+ }
+ if (ramster_nodes_manual_up[node_num]) {
+ pr_err("node %d already up, ignoring\n", (int)node_num);
+ } else {
+ ramster_nodes_manual_up[node_num] = true;
+ o2net_hb_node_up_manual((int)node_num);
+ }
+ return count;
+}
+
+static struct kobj_attribute ramster_manual_node_up_attr = {
+ .attr = { .name = "manual_node_up", .mode = 0644 },
+ .show = ramster_manual_node_up_show,
+ .store = ramster_manual_node_up_store,
+};
+
+static struct attribute *ramster_attrs[] = {
+ &ramster_pers_remotify_enable_attr.attr,
+ &ramster_eph_remotify_enable_attr.attr,
+ &ramster_remote_pers_pages_attr.attr,
+ &ramster_eph_pages_remoted_attr.attr,
+ &ramster_eph_pages_remote_failed_attr.attr,
+ &ramster_pers_pages_remoted_attr.attr,
+ &ramster_pers_pages_remote_failed_attr.attr,
+ &ramster_pers_pages_remote_nomem_attr.attr,
+ &ramster_remote_pages_flushed_attr.attr,
+ &ramster_remote_page_flushes_failed_attr.attr,
+ &ramster_remote_objects_flushed_attr.attr,
+ &ramster_remote_object_flushes_failed_attr.attr,
+ &ramster_remote_eph_pages_succ_get_attr.attr,
+ &ramster_remote_eph_pages_unsucc_get_attr.attr,
+ &ramster_remote_pers_pages_succ_get_attr.attr,
+ &ramster_remote_pers_pages_unsucc_get_attr.attr,
+ &ramster_foreign_eph_pampd_count_attr.attr,
+ &ramster_foreign_eph_pampd_count_max_attr.attr,
+ &ramster_foreign_pers_pampd_count_attr.attr,
+ &ramster_foreign_pers_pampd_count_max_attr.attr,
+ &ramster_curr_flnode_count_attr.attr,
+ &ramster_curr_flnode_count_max_attr.attr,
+ &ramster_manual_node_up_attr.attr,
+ NULL,
+};
+
+static struct attribute_group ramster_attr_group = {
+ .attrs = ramster_attrs,
+ .name = "ramster",
+};
+
#endif /* CONFIG_SYSFS */
/*
* When zcache is disabled ("frozen"), pools can be created and destroyed,
@@ -1510,8 +2567,9 @@ static struct shrinker zcache_shrinker = {
* zcache shims between cleancache/frontswap ops and tmem
*/

-static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp,
- uint32_t index, struct page *page)
+int zcache_put(int cli_id, int pool_id, struct tmem_oid *oidp,
+ uint32_t index, char *data, size_t size,
+ bool raw, int ephemeral)
{
struct tmem_pool *pool;
int ret = -1;
@@ -1522,8 +2580,7 @@ static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp,
goto out;
if (!zcache_freeze && zcache_do_preload(pool) == 0) {
/* preload does preempt_disable on success */
- ret = tmem_put(pool, oidp, index, (char *)(page),
- PAGE_SIZE, 0, is_ephemeral(pool));
+ ret = tmem_put(pool, oidp, index, data, size, raw, ephemeral);
if (ret < 0) {
if (is_ephemeral(pool))
zcache_failed_eph_puts++;
@@ -1543,27 +2600,38 @@ out:
return ret;
}

-static int zcache_get_page(int cli_id, int pool_id, struct tmem_oid *oidp,
- uint32_t index, struct page *page)
+int zcache_get(int cli_id, int pool_id, struct tmem_oid *oidp,
+ uint32_t index, char *data, size_t *sizep,
+ bool raw, int get_and_free)
{
struct tmem_pool *pool;
int ret = -1;
- unsigned long flags;
- size_t size = PAGE_SIZE;
+ bool eph;

- local_irq_save(flags);
+ if (!raw) {
+ BUG_ON(irqs_disabled());
+ BUG_ON(in_softirq());
+ }
pool = zcache_get_pool_by_id(cli_id, pool_id);
+ eph = is_ephemeral(pool);
if (likely(pool != NULL)) {
if (atomic_read(&pool->obj_count) > 0)
- ret = tmem_get(pool, oidp, index, (char *)(page),
- &size, 0, is_ephemeral(pool));
+ ret = tmem_get(pool, oidp, index, data, sizep,
+ raw, get_and_free);
zcache_put_pool(pool);
}
- local_irq_restore(flags);
+ WARN_ONCE((!eph && (ret != 0)), "zcache_get fails on persistent pool, "
+ "bad things are very likely to happen soon\n");
+#ifdef RAMSTER_TESTING
+ if (ret != 0 && ret != -1 && !(ret == -EINVAL && is_ephemeral(pool)))
+ pr_err("TESTING zcache_get tmem_get returns ret=%d\n", ret);
+#endif
+ if (ret == -EAGAIN)
+ BUG(); /* FIXME... don't need this anymore??? let's ensure */
return ret;
}

-static int zcache_flush_page(int cli_id, int pool_id,
+int zcache_flush(int cli_id, int pool_id,
struct tmem_oid *oidp, uint32_t index)
{
struct tmem_pool *pool;
@@ -1573,6 +2641,7 @@ static int zcache_flush_page(int cli_id, int pool_id,
local_irq_save(flags);
zcache_flush_total++;
pool = zcache_get_pool_by_id(cli_id, pool_id);
+ ramster_do_preload_flnode_only(pool);
if (likely(pool != NULL)) {
if (atomic_read(&pool->obj_count) > 0)
ret = tmem_flush_page(pool, oidp, index);
@@ -1584,8 +2653,7 @@ static int zcache_flush_page(int cli_id, int pool_id,
return ret;
}

-static int zcache_flush_object(int cli_id, int pool_id,
- struct tmem_oid *oidp)
+int zcache_flush_object(int cli_id, int pool_id, struct tmem_oid *oidp)
{
struct tmem_pool *pool;
int ret = -1;
@@ -1594,6 +2662,7 @@ static int zcache_flush_object(int cli_id, int pool_id,
local_irq_save(flags);
zcache_flobj_total++;
pool = zcache_get_pool_by_id(cli_id, pool_id);
+ ramster_do_preload_flnode_only(pool);
if (likely(pool != NULL)) {
if (atomic_read(&pool->obj_count) > 0)
ret = tmem_flush_object(pool, oidp);
@@ -1605,7 +2674,7 @@ static int zcache_flush_object(int cli_id, int pool_id,
return ret;
}

-static int zcache_destroy_pool(int cli_id, int pool_id)
+int zcache_client_destroy_pool(int cli_id, int pool_id)
{
struct tmem_pool *pool = NULL;
struct zcache_client *cli = NULL;
@@ -1632,13 +2701,17 @@ static int zcache_destroy_pool(int cli_id, int pool_id)
ret = tmem_destroy_pool(pool);
local_bh_enable();
kfree(pool);
- pr_info("zcache: destroyed pool id=%d, cli_id=%d\n",
- pool_id, cli_id);
+ pr_info("ramster: destroyed pool id=%d cli_id=%d\n", pool_id, cli_id);
out:
return ret;
}

-static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
+static int zcache_destroy_pool(int pool_id)
+{
+ return zcache_client_destroy_pool(LOCAL_CLIENT, pool_id);
+}
+
+int zcache_new_pool(uint16_t cli_id, uint32_t flags)
{
int poolid = -1;
struct tmem_pool *pool;
@@ -1653,7 +2726,7 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
atomic_inc(&cli->refcount);
pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC);
if (pool == NULL) {
- pr_info("zcache: pool creation failed: out of memory\n");
+ pr_info("ramster: pool creation failed: out of memory\n");
goto out;
}

@@ -1661,7 +2734,7 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
if (cli->tmem_pools[poolid] == NULL)
break;
if (poolid >= MAX_POOLS_PER_CLIENT) {
- pr_info("zcache: pool creation failed: max exceeded\n");
+ pr_info("ramster: pool creation failed: max exceeded\n");
kfree(pool);
poolid = -1;
goto out;
@@ -1671,7 +2744,7 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
pool->pool_id = poolid;
tmem_new_pool(pool, flags);
cli->tmem_pools[poolid] = pool;
- pr_info("zcache: created %s tmem pool, id=%d, client=%d\n",
+ pr_info("ramster: created %s tmem pool, id=%d, client=%d\n",
flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
poolid, cli_id);
out:
@@ -1680,6 +2753,64 @@ out:
return poolid;
}

+static int zcache_local_new_pool(uint32_t flags)
+{
+ return zcache_new_pool(LOCAL_CLIENT, flags);
+}
+
+int zcache_autocreate_pool(int cli_id, int pool_id, bool ephemeral)
+{
+ struct tmem_pool *pool;
+ struct zcache_client *cli = NULL;
+ uint32_t flags = ephemeral ? 0 : TMEM_POOL_PERSIST;
+ int ret = -1;
+
+ if (cli_id == LOCAL_CLIENT)
+ goto out;
+ if (pool_id >= MAX_POOLS_PER_CLIENT)
+ goto out;
+ else if ((unsigned int)cli_id < MAX_CLIENTS)
+ cli = &zcache_clients[cli_id];
+ if ((ephemeral && !use_cleancache) || (!ephemeral && !use_frontswap))
+ BUG(); /* FIXME, handle more gracefully later */
+ if (!cli->allocated) {
+ if (zcache_new_client(cli_id))
+ BUG(); /* FIXME, handle more gracefully later */
+ cli = &zcache_clients[cli_id];
+ }
+ atomic_inc(&cli->refcount);
+ pool = cli->tmem_pools[pool_id];
+ if (pool != NULL) {
+ if (pool->persistent && ephemeral) {
+ pr_err("zcache_autocreate_pool: type mismatch\n");
+ goto out;
+ }
+ ret = 0;
+ goto out;
+ }
+ pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL);
+ if (pool == NULL) {
+ pr_info("ramster: pool creation failed: out of memory\n");
+ goto out;
+ }
+ atomic_set(&pool->refcount, 0);
+ pool->client = cli;
+ pool->pool_id = pool_id;
+ tmem_new_pool(pool, flags);
+ cli->tmem_pools[pool_id] = pool;
+ pr_info("ramster: AUTOcreated %s tmem poolid=%d, for remote client=%d\n",
+ flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
+ pool_id, cli_id);
+ ret = 0;
+out:
+ if (cli == NULL)
+ BUG(); /* FIXME, handle more gracefully later */
+ /* pr_err("zcache_autocreate_pool: failed\n"); */
+ if (cli != NULL)
+ atomic_dec(&cli->refcount);
+ return ret;
+}
+
/**********
* Two kernel functionalities currently can be layered on top of tmem.
* These are "cleancache" which is used as a second-chance cache for clean
@@ -1696,8 +2827,18 @@ static void zcache_cleancache_put_page(int pool_id,
u32 ind = (u32) index;
struct tmem_oid oid = *(struct tmem_oid *)&key;

- if (likely(ind == index))
- (void)zcache_put_page(LOCAL_CLIENT, pool_id, &oid, index, page);
+#ifdef __PG_WAS_ACTIVE
+ if (!PageWasActive(page)) {
+ zcache_nonactive_puts++;
+ return;
+ }
+#endif
+ if (likely(ind == index)) {
+ char *kva = page_address(page);
+
+ (void)zcache_put(LOCAL_CLIENT, pool_id, &oid, index,
+ kva, PAGE_SIZE, 0, 1);
+ }
}

static int zcache_cleancache_get_page(int pool_id,
@@ -1708,8 +2849,19 @@ static int zcache_cleancache_get_page(int pool_id,
struct tmem_oid oid = *(struct tmem_oid *)&key;
int ret = -1;

- if (likely(ind == index))
- ret = zcache_get_page(LOCAL_CLIENT, pool_id, &oid, index, page);
+ preempt_disable();
+ if (likely(ind == index)) {
+ char *kva = page_address(page);
+ size_t size = PAGE_SIZE;
+
+ ret = zcache_get(LOCAL_CLIENT, pool_id, &oid, index,
+ kva, &size, 0, 0);
+#ifdef __PG_WAS_ACTIVE
+ if (ret == 0)
+ SetPageWasActive(page);
+#endif
+ }
+ preempt_enable();
return ret;
}

@@ -1721,7 +2873,7 @@ static void zcache_cleancache_flush_page(int pool_id,
struct tmem_oid oid = *(struct tmem_oid *)&key;

if (likely(ind == index))
- (void)zcache_flush_page(LOCAL_CLIENT, pool_id, &oid, ind);
+ (void)zcache_flush(LOCAL_CLIENT, pool_id, &oid, ind);
}

static void zcache_cleancache_flush_inode(int pool_id,
@@ -1735,7 +2887,7 @@ static void zcache_cleancache_flush_inode(int pool_id,
static void zcache_cleancache_flush_fs(int pool_id)
{
if (pool_id >= 0)
- (void)zcache_destroy_pool(LOCAL_CLIENT, pool_id);
+ (void)zcache_destroy_pool(pool_id);
}

static int zcache_cleancache_init_fs(size_t pagesize)
@@ -1743,7 +2895,7 @@ static int zcache_cleancache_init_fs(size_t pagesize)
BUG_ON(sizeof(struct cleancache_filekey) !=
sizeof(struct tmem_oid));
BUG_ON(pagesize != PAGE_SIZE);
- return zcache_new_pool(LOCAL_CLIENT, 0);
+ return zcache_local_new_pool(0);
}

static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize)
@@ -1752,7 +2904,7 @@ static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize)
BUG_ON(sizeof(struct cleancache_filekey) !=
sizeof(struct tmem_oid));
BUG_ON(pagesize != PAGE_SIZE);
- return zcache_new_pool(LOCAL_CLIENT, 0);
+ return zcache_local_new_pool(0);
}

static struct cleancache_ops zcache_cleancache_ops = {
@@ -1781,10 +2933,8 @@ static int zcache_frontswap_poolid = -1;
/*
* Swizzling increases objects per swaptype, increasing tmem concurrency
* for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS
- * Setting SWIZ_BITS to 27 basically reconstructs the swap entry from
- * frontswap_get_page()
*/
-#define SWIZ_BITS 27
+#define SWIZ_BITS 8
#define SWIZ_MASK ((1 << SWIZ_BITS) - 1)
#define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK))
#define iswiz(_ind) (_ind >> SWIZ_BITS)
@@ -1804,12 +2954,14 @@ static int zcache_frontswap_put_page(unsigned type, pgoff_t offset,
struct tmem_oid oid = oswiz(type, ind);
int ret = -1;
unsigned long flags;
+ char *kva;

BUG_ON(!PageLocked(page));
if (likely(ind64 == ind)) {
local_irq_save(flags);
- ret = zcache_put_page(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind), page);
+ kva = page_address(page);
+ ret = zcache_put(LOCAL_CLIENT, zcache_frontswap_poolid,
+ &oid, iswiz(ind), kva, PAGE_SIZE, 0, 0);
local_irq_restore(flags);
}
return ret;
@@ -1825,10 +2977,16 @@ static int zcache_frontswap_get_page(unsigned type, pgoff_t offset,
struct tmem_oid oid = oswiz(type, ind);
int ret = -1;

+ preempt_disable(); /* FIXME, remove this? */
BUG_ON(!PageLocked(page));
- if (likely(ind64 == ind))
- ret = zcache_get_page(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind), page);
+ if (likely(ind64 == ind)) {
+ char *kva = page_address(page);
+ size_t size = PAGE_SIZE;
+
+ ret = zcache_get(LOCAL_CLIENT, zcache_frontswap_poolid,
+ &oid, iswiz(ind), kva, &size, 0, -1);
+ }
+ preempt_enable(); /* FIXME, remove this? */
return ret;
}

@@ -1840,7 +2998,7 @@ static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset)
struct tmem_oid oid = oswiz(type, ind);

if (likely(ind64 == ind))
- (void)zcache_flush_page(LOCAL_CLIENT, zcache_frontswap_poolid,
+ (void)zcache_flush(LOCAL_CLIENT, zcache_frontswap_poolid,
&oid, iswiz(ind));
}

@@ -1862,7 +3020,7 @@ static void zcache_frontswap_init(unsigned ignored)
/* a single tmem poolid is used for all frontswap "types" (swapfiles) */
if (zcache_frontswap_poolid < 0)
zcache_frontswap_poolid =
- zcache_new_pool(LOCAL_CLIENT, TMEM_POOL_PERSIST);
+ zcache_local_new_pool(TMEM_POOL_PERSIST);
}

static struct frontswap_ops zcache_frontswap_ops = {
@@ -1883,19 +3041,125 @@ struct frontswap_ops zcache_frontswap_register_ops(void)
#endif

/*
+ * frontswap selfshrinking
+ */
+
+#ifdef CONFIG_FRONTSWAP
+/* In HZ, controls frequency of worker invocation. */
+static unsigned int selfshrink_interval __read_mostly = 5;
+
+static void selfshrink_process(struct work_struct *work);
+static DECLARE_DELAYED_WORK(selfshrink_worker, selfshrink_process);
+
+/* Enable/disable with sysfs. */
+static bool frontswap_selfshrinking __read_mostly;
+
+/* Enable/disable with kernel boot option. */
+static bool use_frontswap_selfshrink __initdata = true;
+
+/*
+ * The default values for the following parameters were deemed reasonable
+ * by experimentation, may be workload-dependent, and can all be
+ * adjusted via sysfs.
+ */
+
+/* Control rate for frontswap shrinking. Higher hysteresis is slower. */
+static unsigned int frontswap_hysteresis __read_mostly = 20;
+
+/*
+ * Number of selfshrink worker invocations to wait before observing that
+ * frontswap selfshrinking should commence. Note that selfshrinking does
+ * not use a separate worker thread.
+ */
+static unsigned int frontswap_inertia __read_mostly = 3;
+
+/* Countdown to next invocation of frontswap_shrink() */
+static unsigned long frontswap_inertia_counter;
+
+/*
+ * Invoked by the selfshrink worker thread, uses current number of pages
+ * in frontswap (frontswap_curr_pages()), previous status, and control
+ * values (hysteresis and inertia) to determine if frontswap should be
+ * shrunk and what the new frontswap size should be. Note that
+ * frontswap_shrink is essentially a partial swapoff that immediately
+ * transfers pages from the "swap device" (frontswap) back into kernel
+ * RAM; despite the name, frontswap "shrinking" is very different from
+ * the "shrinker" interface used by the kernel MM subsystem to reclaim
+ * memory.
+ */
+static void frontswap_selfshrink(void)
+{
+ static unsigned long cur_frontswap_pages;
+ static unsigned long last_frontswap_pages;
+ static unsigned long tgt_frontswap_pages;
+
+ last_frontswap_pages = cur_frontswap_pages;
+ cur_frontswap_pages = frontswap_curr_pages();
+ if (!cur_frontswap_pages ||
+ (cur_frontswap_pages > last_frontswap_pages)) {
+ frontswap_inertia_counter = frontswap_inertia;
+ return;
+ }
+ if (frontswap_inertia_counter && --frontswap_inertia_counter)
+ return;
+ if (cur_frontswap_pages <= frontswap_hysteresis)
+ tgt_frontswap_pages = 0;
+ else
+ tgt_frontswap_pages = cur_frontswap_pages -
+ (cur_frontswap_pages / frontswap_hysteresis);
+ frontswap_shrink(tgt_frontswap_pages);
+}
+
+static int __init ramster_nofrontswap_selfshrink_setup(char *s)
+{
+ use_frontswap_selfshrink = false;
+ return 1;
+}
+
+__setup("noselfshrink", ramster_nofrontswap_selfshrink_setup);
+
+static void selfshrink_process(struct work_struct *work)
+{
+ if (frontswap_selfshrinking && frontswap_enabled) {
+ frontswap_selfshrink();
+ schedule_delayed_work(&selfshrink_worker,
+ selfshrink_interval * HZ);
+ }
+}
+
+static int ramster_enabled;
+
+static int __init ramster_selfshrink_init(void)
+{
+ frontswap_selfshrinking = ramster_enabled && use_frontswap_selfshrink;
+ if (frontswap_selfshrinking)
+ pr_info("ramster: Initializing frontswap "
+ "selfshrinking driver.\n");
+ else
+ return -ENODEV;
+
+ schedule_delayed_work(&selfshrink_worker, selfshrink_interval * HZ);
+
+ return 0;
+}
+
+subsys_initcall(ramster_selfshrink_init);
+#endif
+
+/*
* zcache initialization
- * NOTE FOR NOW zcache MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR
+ * NOTE FOR NOW ramster MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR
* NOTHING HAPPENS!
*/

-static int zcache_enabled;
+static int ramster_enabled;

-static int __init enable_zcache(char *s)
+static int __init enable_ramster(char *s)
{
- zcache_enabled = 1;
+ ramster_enabled = 1;
return 1;
}
-__setup("zcache", enable_zcache);
+__setup("ramster", enable_ramster);

/* allow independent dynamic disabling of cleancache and frontswap */

@@ -1903,16 +3167,22 @@ static int use_cleancache = 1;

static int __init no_cleancache(char *s)
{
+ pr_info("INIT no_cleancache called\n");
use_cleancache = 0;
return 1;
}

-__setup("nocleancache", no_cleancache);
+/*
+ * FIXME: need to guarantee this gets checked before zcache_init is called
+ * What is the correct way to achieve this?
+ */
+early_param("nocleancache", no_cleancache);

static int use_frontswap = 1;

static int __init no_frontswap(char *s)
{
+ pr_info("INIT no_frontswap called\n");
use_frontswap = 0;
return 1;
}
@@ -1925,20 +3195,22 @@ static int __init zcache_init(void)

#ifdef CONFIG_SYSFS
ret = sysfs_create_group(mm_kobj, &zcache_attr_group);
+ ret = sysfs_create_group(mm_kobj, &ramster_attr_group);
if (ret) {
- pr_err("zcache: can't create sysfs\n");
+ pr_err("ramster: can't create sysfs\n");
goto out;
}
#endif /* CONFIG_SYSFS */
#if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP)
- if (zcache_enabled) {
+ if (ramster_enabled) {
unsigned int cpu;

+ (void)ramster_o2net_register_handlers();
tmem_register_hostops(&zcache_hostops);
tmem_register_pamops(&zcache_pamops);
ret = register_cpu_notifier(&zcache_cpu_notifier_block);
if (ret) {
- pr_err("zcache: can't register cpu notifier\n");
+ pr_err("ramster: can't register cpu notifier\n");
goto out;
}
for_each_online_cpu(cpu) {
@@ -1951,35 +3223,39 @@ static int __init zcache_init(void)
sizeof(struct tmem_objnode), 0, 0, NULL);
zcache_obj_cache = kmem_cache_create("zcache_obj",
sizeof(struct tmem_obj), 0, 0, NULL);
- ret = zcache_new_client(LOCAL_CLIENT);
- if (ret) {
- pr_err("zcache: can't create client\n");
- goto out;
- }
+ ramster_flnode_cache = kmem_cache_create("ramster_flnode",
+ sizeof(struct flushlist_node), 0, 0, NULL);
#endif
#ifdef CONFIG_CLEANCACHE
- if (zcache_enabled && use_cleancache) {
+ pr_info("INIT ramster_enabled=%d use_cleancache=%d\n",
+ ramster_enabled, use_cleancache);
+ if (ramster_enabled && use_cleancache) {
struct cleancache_ops old_ops;

zbud_init();
register_shrinker(&zcache_shrinker);
old_ops = zcache_cleancache_register_ops();
- pr_info("zcache: cleancache enabled using kernel "
+ pr_info("ramster: cleancache enabled using kernel "
"transcendent memory and compression buddies\n");
if (old_ops.init_fs != NULL)
- pr_warning("zcache: cleancache_ops overridden");
+ pr_warning("ramster: cleancache_ops overridden");
}
#endif
#ifdef CONFIG_FRONTSWAP
- if (zcache_enabled && use_frontswap) {
+ pr_info("INIT ramster_enabled=%d use_frontswap=%d\n",
+ ramster_enabled, use_frontswap);
+ if (ramster_enabled && use_frontswap) {
struct frontswap_ops old_ops;

+ zcache_new_client(LOCAL_CLIENT);
old_ops = zcache_frontswap_register_ops();
- pr_info("zcache: frontswap enabled using kernel "
+ pr_info("ramster: frontswap enabled using kernel "
"transcendent memory and xvmalloc\n");
if (old_ops.init != NULL)
- pr_warning("zcache: frontswap_ops overridden");
+ pr_warning("ramster: frontswap_ops overridden");
}
+ if (ramster_enabled && (use_frontswap || use_cleancache))
+ ramster_remotify_init();
#endif
out:
return ret;
--
1.7.1


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