The patch titled
Subject: mm: memcontrol: simplify detecting when the memory+swap limit is hit
has been added to the -mm tree. Its filename is
mm-memcontrol-simplify-detecting-when-the-memoryswap-limit-is-hit.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-simplify-detecting-when-the-memoryswap-limit-is-hit.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-simplify-detecting-when-the-memoryswap-limit-is-hit.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: 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@xxxxxxxxxxx>
Reviewed-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Dave Hansen <dave@xxxxxxxx>
Cc: Greg Thelen <gthelen@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 47 ++++++++++++----------------------------------
1 file changed, 13 insertions(+), 34 deletions(-)
diff -puN mm/memcontrol.c~mm-memcontrol-simplify-detecting-when-the-memoryswap-limit-is-hit mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcontrol-simplify-detecting-when-the-memoryswap-limit-is-hit
+++ a/mm/memcontrol.c
@@ -315,9 +315,6 @@ 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;
@@ -1804,8 +1801,6 @@ static unsigned long mem_cgroup_reclaim(
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)
@@ -2543,16 +2538,17 @@ 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;
@@ -3615,7 +3611,6 @@ static int mem_cgroup_resize_limit(struc
unsigned long long val)
{
int retry_count;
- u64 memswlimit, memlimit;
int ret = 0;
int children = mem_cgroup_count_children(memcg);
u64 curusage, oldusage;
@@ -3642,24 +3637,16 @@ static int mem_cgroup_resize_limit(struc
* 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)
@@ -3684,7 +3671,7 @@ static int mem_cgroup_resize_memsw_limit
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;
@@ -3703,22 +3690,14 @@ static int mem_cgroup_resize_memsw_limit
* 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)
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-page_alloc-fix-zone-allocation-fairness-on-up.patch
mm-remove-misleading-arch_uses_numa_prot_none.patch
mm-page_alloc-determine-migratetype-only-once.patch
mm-remove-noisy-remainder-of-the-scan_unevictable-interface.patch
mm-page_alloc-avoid-wakeup-kswapd-on-the-unintended-node.patch
mm-clean-up-zone-flags.patch
mm-page_alloc-make-paranoid-check-in-move_freepages-a-vm_bug_on.patch
mm-page_alloc-default-node-ordering-on-64-bit-numa-zone-ordering-on-32-bit-v2.patch
memcg-move-memcg_allocfree_cache_params-to-slab_commonc.patch
memcg-dont-call-memcg_update_all_caches-if-new-cache-id-fits.patch
memcg-move-memcg_update_cache_size-to-slab_commonc.patch
mm-memcontrol-do-not-kill-uncharge-batching-in-free_pages_and_swap_cache.patch
mm-memcontrol-simplify-detecting-when-the-memoryswap-limit-is-hit.patch
mm-memcontrol-fix-transparent-huge-page-allocations-under-pressure.patch
linux-next.patch
debugging-keep-track-of-page-owners.patch
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