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mempolicy: reduce stack size of migrate_pages()

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migrate_pages() is using >500 bytes stack. Reduce it.

   mm/mempolicy.c: In function 'sys_migrate_pages':
   mm/mempolicy.c:1344: warning: the frame size of 528 bytes is larger than 512 bytes

[akpm@linux-foundation.org: don't play with a might-be-NULL pointer]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KOSAKI Motohiro 2010-08-09 17:19:01 -07:00 committed by Linus Torvalds
parent 2510600060
commit 596d7cfa2b
1 changed files with 26 additions and 14 deletions
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40
mm/mempolicy.c
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@ -1275,33 +1275,42 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
const unsigned long __user *, new_nodes) const unsigned long __user *, new_nodes)
{ {
const struct cred *cred = current_cred(), *tcred; const struct cred *cred = current_cred(), *tcred;
struct mm_struct *mm; struct mm_struct *mm = NULL;
struct task_struct *task; struct task_struct *task;
nodemask_t old;
nodemask_t new;
nodemask_t task_nodes; nodemask_t task_nodes;
int err; int err;
nodemask_t *old;
nodemask_t *new;
NODEMASK_SCRATCH(scratch);
err = get_nodes(&old, old_nodes, maxnode); if (!scratch)
if (err) return -ENOMEM;
return err;
err = get_nodes(&new, new_nodes, maxnode); old = &scratch->mask1;
new = &scratch->mask2;
err = get_nodes(old, old_nodes, maxnode);
if (err) if (err)
return err; goto out;
err = get_nodes(new, new_nodes, maxnode);
if (err)
goto out;
/* Find the mm_struct */ /* Find the mm_struct */
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
task = pid ? find_task_by_vpid(pid) : current; task = pid ? find_task_by_vpid(pid) : current;
if (!task) { if (!task) {
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
return -ESRCH; err = -ESRCH;
goto out;
} }
mm = get_task_mm(task); mm = get_task_mm(task);
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
err = -EINVAL;
if (!mm) if (!mm)
return -EINVAL; goto out;
/* /*
* Check if this process has the right to modify the specified * Check if this process has the right to modify the specified
@ -1322,12 +1331,12 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
task_nodes = cpuset_mems_allowed(task); task_nodes = cpuset_mems_allowed(task);
/* Is the user allowed to access the target nodes? */ /* Is the user allowed to access the target nodes? */
if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) { if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
err = -EPERM; err = -EPERM;
goto out; goto out;
} }
if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) { if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {
err = -EINVAL; err = -EINVAL;
goto out; goto out;
} }
@ -1336,10 +1345,13 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
if (err) if (err)
goto out; goto out;
err = do_migrate_pages(mm, &old, &new, err = do_migrate_pages(mm, old, new,
capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
out: out:
mmput(mm); if (mm)
mmput(mm);
NODEMASK_SCRATCH_FREE(scratch);
return err; return err;
} }