Eric Lee / linux-smarc-t335x-v3.2

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Commit c9b0ed51483cc2fc42bb801b6675c4231b0e4634

Authored by KAMEZAWA Hiroyuki
Committed by Linus Torvalds
1 parent 69029cd550
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

memcg: helper function for relcaim from shmem. 

A new call, mem_cgroup_shrink_usage() is added for shmem handling and
relacing non-standard usage of mem_cgroup_charge/uncharge.

Now, shmem calls mem_cgroup_charge() just for reclaim some pages from
mem_cgroup.  In general, shmem is used by some process group and not for
global resource (like file caches).  So, it's reasonable to reclaim pages
from mem_cgroup where shmem is mainly used.

[hugh@veritas.com: shmem_getpage release page sooner]
[hugh@veritas.com: mem_cgroup_shrink_usage css_put]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 3 changed files with 37 additions and 7 deletions Side-by-side Diff

include/linux/memcontrol.h
Diff comments   View file @ c9b0ed5
... ... @@ -37,6 +37,8 @@
37 37 extern void mem_cgroup_uncharge_page(struct page *page);
38 38 extern void mem_cgroup_uncharge_cache_page(struct page *page);
39 39 extern void mem_cgroup_move_lists(struct page *page, bool active);
  40 +extern int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask);
  41 +
40 42 extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
41 43 struct list_head *dst,
42 44 unsigned long *scanned, int order,
... ... @@ -100,6 +102,11 @@
100 102  
101 103 static inline void mem_cgroup_uncharge_cache_page(struct page *page)
102 104 {
  105 +}
  106 +
  107 +static inline int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
  108 +{
  109 + return 0;
103 110 }
104 111  
105 112 static inline void mem_cgroup_move_lists(struct page *page, bool active)
... ... @@ -781,6 +781,32 @@
781 781 }
782 782  
783 783 /*
  784 + * A call to try to shrink memory usage under specified resource controller.
  785 + * This is typically used for page reclaiming for shmem for reducing side
  786 + * effect of page allocation from shmem, which is used by some mem_cgroup.
  787 + */
  788 +int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
  789 +{
  790 + struct mem_cgroup *mem;
  791 + int progress = 0;
  792 + int retry = MEM_CGROUP_RECLAIM_RETRIES;
  793 +
  794 + rcu_read_lock();
  795 + mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
  796 + css_get(&mem->css);
  797 + rcu_read_unlock();
  798 +
  799 + do {
  800 + progress = try_to_free_mem_cgroup_pages(mem, gfp_mask);
  801 + } while (!progress && --retry);
  802 +
  803 + css_put(&mem->css);
  804 + if (!retry)
  805 + return -ENOMEM;
  806 + return 0;
  807 +}
  808 +
  809 +/*
784 810 * This routine traverse page_cgroup in given list and drop them all.
785 811 * *And* this routine doesn't reclaim page itself, just removes page_cgroup.
786 812 */
... ... @@ -1315,17 +1315,14 @@
1315 1315 shmem_swp_unmap(entry);
1316 1316 spin_unlock(&info->lock);
1317 1317 unlock_page(swappage);
  1318 + page_cache_release(swappage);
1318 1319 if (error == -ENOMEM) {
1319 1320 /* allow reclaim from this memory cgroup */
1320   - error = mem_cgroup_cache_charge(swappage,
1321   - current->mm, gfp & ~__GFP_HIGHMEM);
1322   - if (error) {
1323   - page_cache_release(swappage);
  1321 + error = mem_cgroup_shrink_usage(current->mm,
  1322 + gfp);
  1323 + if (error)
1324 1324 goto failed;
1325   - }
1326   - mem_cgroup_uncharge_cache_page(swappage);
1327 1325 }
1328   - page_cache_release(swappage);
1329 1326 goto repeat;
1330 1327 }
1331 1328 } else if (sgp == SGP_READ && !filepage) {