lkml.org 
[lkml]   [2008]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 1/4] mempolicy: convert MPOL constants to enum
The mempolicy mode constants, MPOL_DEFAULT, MPOL_PREFERRED, MPOL_BIND,
and MPOL_INTERLEAVE, are better declared as part of an enum for type
checking.

The policy member of struct mempolicy is also converted from type short
to type unsigned short. A negative policy does not have any legitimate
meaning, so it is possible to change its type in preparation for adding
optional mode flags later.

The equivalent member of struct shmem_sb_info is also changed from int
to unsigned short.

For compatibility, the policy formal to get_mempolicy() remains as a
pointer to an int:

int get_mempolicy(int *policy, unsigned long *nmask,
unsigned long maxnode, unsigned long addr,
unsigned long flags);

although the only possible values is the range of type unsigned short.

Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@google.com>
---
Applies on top of V3 of Lee Schermerhorn's mempolicy patch posted to
LKML on February 8.

include/linux/mempolicy.h | 21 +++++++++++----------
include/linux/shmem_fs.h | 2 +-
mm/mempolicy.c | 29 +++++++++++++++++------------
mm/shmem.c | 11 ++++++-----
4 files changed, 35 insertions(+), 28 deletions(-)

diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -9,12 +9,13 @@
*/

/* Policies */
-#define MPOL_DEFAULT 0
-#define MPOL_PREFERRED 1
-#define MPOL_BIND 2
-#define MPOL_INTERLEAVE 3
-
-#define MPOL_MAX MPOL_INTERLEAVE
+enum mempolicy_mode {
+ MPOL_DEFAULT,
+ MPOL_PREFERRED,
+ MPOL_BIND,
+ MPOL_INTERLEAVE,
+ MPOL_MAX, /* always last member of mempolicy_mode */
+};

/* Flags for get_mem_policy */
#define MPOL_F_NODE (1<<0) /* return next IL mode instead of node mask */
@@ -62,7 +63,7 @@ struct mm_struct;
*/
struct mempolicy {
atomic_t refcnt;
- short policy; /* See MPOL_* above */
+ unsigned short policy; /* See MPOL_* above */
union {
struct zonelist *zonelist; /* bind */
short preferred_node; /* preferred */
@@ -133,8 +134,8 @@ struct shared_policy {
spinlock_t lock;
};

-void mpol_shared_policy_init(struct shared_policy *info, int policy,
- nodemask_t *nodes);
+void mpol_shared_policy_init(struct shared_policy *info,
+ enum mempolicy_mode policy, nodemask_t *nodes);
int mpol_set_shared_policy(struct shared_policy *info,
struct vm_area_struct *vma,
struct mempolicy *new);
@@ -200,7 +201,7 @@ static inline int mpol_set_shared_policy(struct shared_policy *info,
}

static inline void mpol_shared_policy_init(struct shared_policy *info,
- int policy, nodemask_t *nodes)
+ enum mempolicy_type policy, nodemask_t *nodes)
{
}

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -34,7 +34,7 @@ struct shmem_sb_info {
uid_t uid; /* Mount uid for root directory */
gid_t gid; /* Mount gid for root directory */
mode_t mode; /* Mount mode for root directory */
- int policy; /* Default NUMA memory alloc policy */
+ unsigned short policy; /* Default NUMA memory alloc policy */
nodemask_t policy_nodes; /* nodemask for preferred and bind */
};

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -114,7 +114,7 @@ static void mpol_rebind_policy(struct mempolicy *pol,
const nodemask_t *newmask);

/* Do sanity checking on a policy */
-static int mpol_check_policy(int mode, nodemask_t *nodes)
+static int mpol_check_policy(enum mempolicy_mode mode, nodemask_t *nodes)
{
int was_empty, is_empty;

@@ -159,6 +159,8 @@ static int mpol_check_policy(int mode, nodemask_t *nodes)
if (!was_empty && is_empty)
return -EINVAL;
break;
+ default:
+ BUG();
}
return 0;
}
@@ -201,7 +203,7 @@ static struct zonelist *bind_zonelist(nodemask_t *nodes)
}

/* Create a new policy */
-static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
+static struct mempolicy *mpol_new(enum mempolicy_mode mode, nodemask_t *nodes)
{
struct mempolicy *policy;

@@ -235,6 +237,8 @@ static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
return error_code;
}
break;
+ default:
+ BUG();
}
policy->policy = mode;
policy->cpuset_mems_allowed = cpuset_mems_allowed(current);
@@ -479,7 +483,7 @@ static void mpol_set_task_struct_flag(void)
}

/* Set the process memory policy */
-static long do_set_mempolicy(int mode, nodemask_t *nodes)
+static long do_set_mempolicy(enum mempolicy_mode mode, nodemask_t *nodes)
{
struct mempolicy *new;

@@ -781,7 +785,7 @@ static struct page *new_vma_page(struct page *page, unsigned long private, int *
#endif

static long do_mbind(unsigned long start, unsigned long len,
- unsigned long mode, nodemask_t *nmask,
+ enum mempolicy_mode mode, nodemask_t *nmask,
unsigned long flags)
{
struct vm_area_struct *vma;
@@ -791,9 +795,8 @@ static long do_mbind(unsigned long start, unsigned long len,
int err;
LIST_HEAD(pagelist);

- if ((flags & ~(unsigned long)(MPOL_MF_STRICT |
+ if (flags & ~(unsigned long)(MPOL_MF_STRICT |
MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
- || mode > MPOL_MAX)
return -EINVAL;
if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
return -EPERM;
@@ -826,7 +829,7 @@ static long do_mbind(unsigned long start, unsigned long len,
if (!new)
flags |= MPOL_MF_DISCONTIG_OK;

- pr_debug("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len,
+ pr_debug("mbind %lx-%lx mode:%d nodes:%lx\n",start,start+len,
mode, nmask ? nodes_addr(*nmask)[0] : -1);

down_write(&mm->mmap_sem);
@@ -927,6 +930,8 @@ asmlinkage long sys_mbind(unsigned long start, unsigned long len,
nodemask_t nodes;
int err;

+ if (mode >= MPOL_MAX)
+ return -EINVAL;
err = get_nodes(&nodes, nmask, maxnode);
if (err)
return err;
@@ -940,7 +945,7 @@ asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask,
int err;
nodemask_t nodes;

- if (mode < 0 || mode > MPOL_MAX)
+ if (mode < 0 || mode >= MPOL_MAX)
return -EINVAL;
err = get_nodes(&nodes, nmask, maxnode);
if (err)
@@ -1206,7 +1211,7 @@ static unsigned interleave_nodes(struct mempolicy *policy)
*/
unsigned slab_node(struct mempolicy *policy)
{
- int pol = policy ? policy->policy : MPOL_DEFAULT;
+ enum mempolicy_mode pol = policy ? policy->policy : MPOL_DEFAULT;

switch (pol) {
case MPOL_INTERLEAVE:
@@ -1634,8 +1639,8 @@ restart:
return 0;
}

-void mpol_shared_policy_init(struct shared_policy *info, int policy,
- nodemask_t *policy_nodes)
+void mpol_shared_policy_init(struct shared_policy *info,
+ enum mempolicy_mode policy, nodemask_t *policy_nodes)
{
info->root = RB_ROOT;
spin_lock_init(&info->lock);
@@ -1853,7 +1858,7 @@ static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
char *p = buffer;
int l;
nodemask_t nodes;
- int mode = pol ? pol->policy : MPOL_DEFAULT;
+ enum mempolicy_mode mode = pol ? pol->policy : MPOL_DEFAULT;

switch (mode) {
case MPOL_DEFAULT:
diff --git a/mm/shmem.c b/mm/shmem.c
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1082,7 +1082,8 @@ redirty:

#ifdef CONFIG_NUMA
#ifdef CONFIG_TMPFS
-static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes)
+static int shmem_parse_mpol(char *value, unsigned short *policy,
+ nodemask_t *policy_nodes)
{
char *nodelist = strchr(value, ':');
int err = 1;
@@ -1131,7 +1132,7 @@ out:
return err;
}

-static void shmem_show_mpol(struct seq_file *seq, int policy,
+static void shmem_show_mpol(struct seq_file *seq, enum mempolicy_mode policy,
const nodemask_t policy_nodes)
{
char *policy_string;
@@ -1200,14 +1201,14 @@ static struct page *shmem_alloc_page(gfp_t gfp,
}
#else /* !CONFIG_NUMA */
#ifdef CONFIG_TMPFS
-static inline int shmem_parse_mpol(char *value, int *policy,
+static inline int shmem_parse_mpol(char *value, unsigned short *policy,
nodemask_t *policy_nodes)
{
return 1;
}

-static inline void shmem_show_mpol(struct seq_file *seq, int policy,
- const nodemask_t policy_nodes)
+static inline void shmem_show_mpol(struct seq_file *seq,
+ enum mempolicy_mode policy, const nodemask_t policy_nodes)
{
}
#endif /* CONFIG_TMPFS */

\
 
 \ /
  Last update: 2008-02-11 16:33    [W:0.118 / U:2.824 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site