lkml.org 
[lkml]   [2009]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC][PATCH 2/9] soft limit framework for memcg.
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

Add minimal modification for soft limit to res_counter_charge() and memcontol.c
Based on Balbir Singh <balbir@linux.vnet.ibm.com> 's work but most of
features are removed. (dropped or moved to later patch.)

This is for building a frame to implement soft limit handler in memcg.
- Checks soft limit status at every charge.
- Adds mem_cgroup_soft_limit_check() as a function to detect we need
check now or not.
- mem_cgroup_update_soft_limit() is a function for updates internal status
of soft limit controller of memcg.
- As an experimental, this has no hooks in uncharge path.

Changelog: v1 -> v2
- removed "update" from mem_cgroup_free() (revisit in later patch.)

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
---
include/linux/res_counter.h | 3 ++-
kernel/res_counter.c | 12 +++++++++++-
mm/memcontrol.c | 19 +++++++++++++++++--
3 files changed, 30 insertions(+), 4 deletions(-)
Index: softlimit-test2/include/linux/res_counter.h
===================================================================
--- softlimit-test2.orig/include/linux/res_counter.h
+++ softlimit-test2/include/linux/res_counter.h
@@ -112,7 +112,8 @@ void res_counter_init(struct res_counter
int __must_check res_counter_charge_locked(struct res_counter *counter,
unsigned long val);
int __must_check res_counter_charge(struct res_counter *counter,
- unsigned long val, struct res_counter **limit_fail_at);
+ unsigned long val, struct res_counter **limit_fail_at,
+ bool *soft_limit_failure);

/*
* uncharge - tell that some portion of the resource is released
Index: softlimit-test2/kernel/res_counter.c
===================================================================
--- softlimit-test2.orig/kernel/res_counter.c
+++ softlimit-test2/kernel/res_counter.c
@@ -37,9 +37,11 @@ int res_counter_charge_locked(struct res
}

int res_counter_charge(struct res_counter *counter, unsigned long val,
- struct res_counter **limit_fail_at)
+ struct res_counter **limit_fail_at,
+ bool *soft_limit_failure)
{
int ret;
+ int soft_cnt = 0;
unsigned long flags;
struct res_counter *c, *u;

@@ -48,6 +50,8 @@ int res_counter_charge(struct res_counte
for (c = counter; c != NULL; c = c->parent) {
spin_lock(&c->lock);
ret = res_counter_charge_locked(c, val);
+ if (!res_counter_soft_limit_check_locked(c))
+ soft_cnt += 1;
spin_unlock(&c->lock);
if (ret < 0) {
*limit_fail_at = c;
@@ -55,6 +59,12 @@ int res_counter_charge(struct res_counte
}
}
ret = 0;
+ if (soft_limit_failure) {
+ if (!soft_cnt)
+ *soft_limit_failure = false;
+ else
+ *soft_limit_failure = true;
+ }
goto done;
undo:
for (u = counter; u != c; u = u->parent) {
Index: softlimit-test2/mm/memcontrol.c
===================================================================
--- softlimit-test2.orig/mm/memcontrol.c
+++ softlimit-test2/mm/memcontrol.c
@@ -897,6 +897,15 @@ static void record_last_oom(struct mem_c
mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
}

+static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem)
+{
+ return false;
+}
+
+static void mem_cgroup_update_soft_limit(struct mem_cgroup *mem)
+{
+ return;
+}

/*
* Unlike exported interface, "oom" parameter is added. if oom==true,
@@ -909,6 +918,7 @@ static int __mem_cgroup_try_charge(struc
struct mem_cgroup *mem, *mem_over_limit;
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
struct res_counter *fail_res;
+ bool soft_fail;

if (unlikely(test_thread_flag(TIF_MEMDIE))) {
/* Don't account this! */
@@ -938,12 +948,13 @@ static int __mem_cgroup_try_charge(struc
int ret;
bool noswap = false;

- ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res);
+ ret = res_counter_charge(&mem->res, PAGE_SIZE, &fail_res,
+ &soft_fail);
if (likely(!ret)) {
if (!do_swap_account)
break;
ret = res_counter_charge(&mem->memsw, PAGE_SIZE,
- &fail_res);
+ &fail_res, NULL);
if (likely(!ret))
break;
/* mem+swap counter fails */
@@ -985,6 +996,10 @@ static int __mem_cgroup_try_charge(struc
goto nomem;
}
}
+
+ if (soft_fail && mem_cgroup_soft_limit_check(mem))
+ mem_cgroup_update_soft_limit(mem);
+
return 0;
nomem:
css_put(&mem->css);


\
 
 \ /
  Last update: 2009-04-03 10:15    [from the cache]
©2003-2011 Jasper Spaans