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cpuset: alloc nodemask_t on the heap rather than the stack
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Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Miao Xie authored and Linus Torvalds committed Mar 24, 2010
1 parent 5ab116c commit 53feb29
Showing 1 changed file with 66 additions and 28 deletions.
94 changes: 66 additions & 28 deletions kernel/cpuset.c
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Original file line number Diff line number Diff line change
Expand Up @@ -970,15 +970,20 @@ static void cpuset_change_nodemask(struct task_struct *p,
struct cpuset *cs;
int migrate;
const nodemask_t *oldmem = scan->data;
nodemask_t newmems;
NODEMASK_ALLOC(nodemask_t, newmems, GFP_KERNEL);

if (!newmems)
return;

cs = cgroup_cs(scan->cg);
guarantee_online_mems(cs, &newmems);
guarantee_online_mems(cs, newmems);

task_lock(p);
cpuset_change_task_nodemask(p, &newmems);
cpuset_change_task_nodemask(p, newmems);
task_unlock(p);

NODEMASK_FREE(newmems);

mm = get_task_mm(p);
if (!mm)
return;
Expand Down Expand Up @@ -1048,16 +1053,21 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem,
static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
const char *buf)
{
nodemask_t oldmem;
NODEMASK_ALLOC(nodemask_t, oldmem, GFP_KERNEL);
int retval;
struct ptr_heap heap;

if (!oldmem)
return -ENOMEM;

/*
* top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY];
* it's read-only
*/
if (cs == &top_cpuset)
return -EACCES;
if (cs == &top_cpuset) {
retval = -EACCES;
goto done;
}

/*
* An empty mems_allowed is ok iff there are no tasks in the cpuset.
Expand All @@ -1073,11 +1083,13 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
goto done;

if (!nodes_subset(trialcs->mems_allowed,
node_states[N_HIGH_MEMORY]))
return -EINVAL;
node_states[N_HIGH_MEMORY])) {
retval = -EINVAL;
goto done;
}
}
oldmem = cs->mems_allowed;
if (nodes_equal(oldmem, trialcs->mems_allowed)) {
*oldmem = cs->mems_allowed;
if (nodes_equal(*oldmem, trialcs->mems_allowed)) {
retval = 0; /* Too easy - nothing to do */
goto done;
}
Expand All @@ -1093,10 +1105,11 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
cs->mems_allowed = trialcs->mems_allowed;
mutex_unlock(&callback_mutex);

update_tasks_nodemask(cs, &oldmem, &heap);
update_tasks_nodemask(cs, oldmem, &heap);

heap_free(&heap);
done:
NODEMASK_FREE(oldmem);
return retval;
}

Expand Down Expand Up @@ -1381,39 +1394,47 @@ static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
struct cgroup *oldcont, struct task_struct *tsk,
bool threadgroup)
{
nodemask_t from, to;
struct mm_struct *mm;
struct cpuset *cs = cgroup_cs(cont);
struct cpuset *oldcs = cgroup_cs(oldcont);
NODEMASK_ALLOC(nodemask_t, from, GFP_KERNEL);
NODEMASK_ALLOC(nodemask_t, to, GFP_KERNEL);

if (from == NULL || to == NULL)
goto alloc_fail;

if (cs == &top_cpuset) {
cpumask_copy(cpus_attach, cpu_possible_mask);
} else {
guarantee_online_cpus(cs, cpus_attach);
}
guarantee_online_mems(cs, &to);
guarantee_online_mems(cs, to);

/* do per-task migration stuff possibly for each in the threadgroup */
cpuset_attach_task(tsk, &to, cs);
cpuset_attach_task(tsk, to, cs);
if (threadgroup) {
struct task_struct *c;
rcu_read_lock();
list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
cpuset_attach_task(c, &to, cs);
cpuset_attach_task(c, to, cs);
}
rcu_read_unlock();
}

/* change mm; only needs to be done once even if threadgroup */
from = oldcs->mems_allowed;
to = cs->mems_allowed;
*from = oldcs->mems_allowed;
*to = cs->mems_allowed;
mm = get_task_mm(tsk);
if (mm) {
mpol_rebind_mm(mm, &to);
mpol_rebind_mm(mm, to);
if (is_memory_migrate(cs))
cpuset_migrate_mm(mm, &from, &to);
cpuset_migrate_mm(mm, from, to);
mmput(mm);
}

alloc_fail:
NODEMASK_FREE(from);
NODEMASK_FREE(to);
}

/* The various types of files and directories in a cpuset file system */
Expand Down Expand Up @@ -1558,13 +1579,21 @@ static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs)

static int cpuset_sprintf_memlist(char *page, struct cpuset *cs)
{
nodemask_t mask;
NODEMASK_ALLOC(nodemask_t, mask, GFP_KERNEL);
int retval;

if (mask == NULL)
return -ENOMEM;

mutex_lock(&callback_mutex);
mask = cs->mems_allowed;
*mask = cs->mems_allowed;
mutex_unlock(&callback_mutex);

return nodelist_scnprintf(page, PAGE_SIZE, mask);
retval = nodelist_scnprintf(page, PAGE_SIZE, *mask);

NODEMASK_FREE(mask);

return retval;
}

static ssize_t cpuset_common_file_read(struct cgroup *cont,
Expand Down Expand Up @@ -1993,7 +2022,10 @@ static void scan_for_empty_cpusets(struct cpuset *root)
struct cpuset *cp; /* scans cpusets being updated */
struct cpuset *child; /* scans child cpusets of cp */
struct cgroup *cont;
nodemask_t oldmems;
NODEMASK_ALLOC(nodemask_t, oldmems, GFP_KERNEL);

if (oldmems == NULL)
return;

list_add_tail((struct list_head *)&root->stack_list, &queue);

Expand All @@ -2010,7 +2042,7 @@ static void scan_for_empty_cpusets(struct cpuset *root)
nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY]))
continue;

oldmems = cp->mems_allowed;
*oldmems = cp->mems_allowed;

/* Remove offline cpus and mems from this cpuset. */
mutex_lock(&callback_mutex);
Expand All @@ -2026,9 +2058,10 @@ static void scan_for_empty_cpusets(struct cpuset *root)
remove_tasks_in_empty_cpuset(cp);
else {
update_tasks_cpumask(cp, NULL);
update_tasks_nodemask(cp, &oldmems, NULL);
update_tasks_nodemask(cp, oldmems, NULL);
}
}
NODEMASK_FREE(oldmems);
}

/*
Expand Down Expand Up @@ -2086,16 +2119,19 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb,
static int cpuset_track_online_nodes(struct notifier_block *self,
unsigned long action, void *arg)
{
nodemask_t oldmems;
NODEMASK_ALLOC(nodemask_t, oldmems, GFP_KERNEL);

if (oldmems == NULL)
return NOTIFY_DONE;

cgroup_lock();
switch (action) {
case MEM_ONLINE:
oldmems = top_cpuset.mems_allowed;
*oldmems = top_cpuset.mems_allowed;
mutex_lock(&callback_mutex);
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
mutex_unlock(&callback_mutex);
update_tasks_nodemask(&top_cpuset, &oldmems, NULL);
update_tasks_nodemask(&top_cpuset, oldmems, NULL);
break;
case MEM_OFFLINE:
/*
Expand All @@ -2108,6 +2144,8 @@ static int cpuset_track_online_nodes(struct notifier_block *self,
break;
}
cgroup_unlock();

NODEMASK_FREE(oldmems);
return NOTIFY_OK;
}
#endif
Expand Down

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