Messages in this thread Patch in this message | | | Date | Thu, 15 May 2008 18:31:49 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | [PATCH -mm 3/5] memcg: helper function for relcaim from shmem. |
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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.
Changelog v3->v4 - fixed while loop to be do_while loop. - fixed declaration in header file. - adjusted to 2.6.26-rc2-mm1
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
--- include/linux/memcontrol.h | 7 +++++++ mm/memcontrol.c | 25 +++++++++++++++++++++++++ mm/shmem.c | 5 ++--- 3 files changed, 34 insertions(+), 3 deletions(-)
Index: mm-2.6.26-rc2-mm1/mm/memcontrol.c =================================================================== --- mm-2.6.26-rc2-mm1.orig/mm/memcontrol.c +++ mm-2.6.26-rc2-mm1/mm/memcontrol.c @@ -770,6 +770,31 @@ void mem_cgroup_end_migration(struct pag } /* + * A call to try to shrink memory usage under specified resource controller. + * This is typically used for page reclaiming for shmem for reducing side + * effect of page allocation from shmem, which is used by some mem_cgroup. + */ +int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask) +{ + struct mem_cgroup *mem; + int progress = 0; + int retry = MEM_CGROUP_RECLAIM_RETRIES; + + rcu_read_lock(); + mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); + css_get(&mem->css); + rcu_read_unlock(); + + do { + progress = try_to_free_mem_cgroup_pages(mem, gfp_mask); + } while (!progress && --retry); + + if (!retry) + return -ENOMEM; + return 0; +} + +/* * This routine traverse page_cgroup in given list and drop them all. * *And* this routine doesn't reclaim page itself, just removes page_cgroup. */ Index: mm-2.6.26-rc2-mm1/mm/shmem.c =================================================================== --- mm-2.6.26-rc2-mm1.orig/mm/shmem.c +++ mm-2.6.26-rc2-mm1/mm/shmem.c @@ -1321,13 +1321,12 @@ repeat: unlock_page(swappage); if (error == -ENOMEM) { /* allow reclaim from this memory cgroup */ - error = mem_cgroup_cache_charge(swappage, - current->mm, gfp & ~__GFP_HIGHMEM); + error = mem_cgroup_shrink_usage(current->mm, + gfp & ~__GFP_HIGHMEM); if (error) { page_cache_release(swappage); goto failed; } - mem_cgroup_uncharge_cache_page(swappage); } page_cache_release(swappage); goto repeat; Index: mm-2.6.26-rc2-mm1/include/linux/memcontrol.h =================================================================== --- mm-2.6.26-rc2-mm1.orig/include/linux/memcontrol.h +++ mm-2.6.26-rc2-mm1/include/linux/memcontrol.h @@ -37,6 +37,8 @@ extern int mem_cgroup_cache_charge(struc extern void mem_cgroup_uncharge_page(struct page *page); extern void mem_cgroup_uncharge_cache_page(struct page *page); extern void mem_cgroup_move_lists(struct page *page, bool active); +extern int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask); + extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, struct list_head *dst, unsigned long *scanned, int order, @@ -102,6 +104,11 @@ static inline void mem_cgroup_uncharge_c { } +static inline int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask) +{ + return 0; +} + static inline void mem_cgroup_move_lists(struct page *page, bool active) { }
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