mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

mm: memcontrol: simplify detecting when the memory+swap limit is hit 

When attempting to charge pages, we first charge the memory counter and
then the memory+swap counter.  If one of the counters is at its limit, we
enter reclaim, but if it's the memory+swap counter, reclaim shouldn't swap
because that wouldn't change the situation.  However, if the counters have
the same limits, we never get to the memory+swap limit.  To know whether
reclaim should swap or not, there is a state flag that indicates whether
the limits are equal and whether hitting the memory limit implies hitting
the memory+swap limit.

Just try the memory+swap counter first.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Dave Hansen <dave@sr71.net>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2014-10-09 15:28:54 -07:00 committed by Linus Torvalds
parent aabfb57296
commit 3fbe724424
1 changed files with 13 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
mm/memcontrol.c
View File

@ -318,9 +318,6 @@ struct mem_cgroup {
/* OOM-Killer disable */
int oom_kill_disable;
/* set when res.limit == memsw.limit */
bool memsw_is_minimum;
/* protect arrays of thresholds */
struct mutex thresholds_lock;
@ -1818,8 +1815,6 @@ static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
noswap = true;
if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
noswap = true;
for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
if (loop)
@ -2557,16 +2552,17 @@ retry:
goto done;
size = batch * PAGE_SIZE;
if (!res_counter_charge(&memcg->res, size, &fail_res)) {
if (!do_swap_account)
if (!do_swap_account ||
!res_counter_charge(&memcg->memsw, size, &fail_res)) {
if (!res_counter_charge(&memcg->res, size, &fail_res))
goto done_restock;
if (!res_counter_charge(&memcg->memsw, size, &fail_res))
goto done_restock;
res_counter_uncharge(&memcg->res, size);
if (do_swap_account)
res_counter_uncharge(&memcg->memsw, size);
mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
} else {
mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
flags |= MEM_CGROUP_RECLAIM_NOSWAP;
} else
mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
}
if (batch > nr_pages) {
batch = nr_pages;
@ -3629,7 +3625,6 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
unsigned long long val)
{
int retry_count;
u64 memswlimit, memlimit;
int ret = 0;
int children = mem_cgroup_count_children(memcg);
u64 curusage, oldusage;
@ -3656,24 +3651,16 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
* We have to guarantee memcg->res.limit <= memcg->memsw.limit.
*/
mutex_lock(&set_limit_mutex);
memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
if (memswlimit < val) {
if (res_counter_read_u64(&memcg->memsw, RES_LIMIT) < val) {
ret = -EINVAL;
mutex_unlock(&set_limit_mutex);
break;
}
memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
if (memlimit < val)
if (res_counter_read_u64(&memcg->res, RES_LIMIT) < val)
enlarge = 1;
ret = res_counter_set_limit(&memcg->res, val);
if (!ret) {
if (memswlimit == val)
memcg->memsw_is_minimum = true;
else
memcg->memsw_is_minimum = false;
}
mutex_unlock(&set_limit_mutex);
if (!ret)
@ -3698,7 +3685,7 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
unsigned long long val)
{
int retry_count;
u64 memlimit, memswlimit, oldusage, curusage;
u64 oldusage, curusage;
int children = mem_cgroup_count_children(memcg);
int ret = -EBUSY;
int enlarge = 0;
@ -3717,22 +3704,14 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
* We have to guarantee memcg->res.limit <= memcg->memsw.limit.
*/
mutex_lock(&set_limit_mutex);
memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
if (memlimit > val) {
if (res_counter_read_u64(&memcg->res, RES_LIMIT) > val) {
ret = -EINVAL;
mutex_unlock(&set_limit_mutex);
break;
}
memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
if (memswlimit < val)
if (res_counter_read_u64(&memcg->memsw, RES_LIMIT) < val)
enlarge = 1;
ret = res_counter_set_limit(&memcg->memsw, val);
if (!ret) {
if (memlimit == val)
memcg->memsw_is_minimum = true;
else
memcg->memsw_is_minimum = false;
}
mutex_unlock(&set_limit_mutex);
if (!ret)