From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 14 May 2008 17:10:25 +0900 From: KAMEZAWA Hiroyuki Subject: [RFC/PATCH 4/6] memcg: shmem reclaim helper Message-Id: <20080514171025.2f0fb1ca.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20080514170236.23c9ddd7.kamezawa.hiroyu@jp.fujitsu.com> References: <20080514170236.23c9ddd7.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: LKML , "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "lizf@cn.fujitsu.com" , "xemul@openvz.org" , "yamamoto@valinux.co.jp" , "hugh@veritas.com" , Andrew Morton List-ID: A new call, mem_cgroup_shrink_usage() is added for shmem handling and removing not usual 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. Signed-off-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) Index: linux-2.6.26-rc2/mm/memcontrol.c =================================================================== --- linux-2.6.26-rc2.orig/mm/memcontrol.c +++ linux-2.6.26-rc2/mm/memcontrol.c @@ -783,6 +783,30 @@ static void mem_cgroup_drop_all_pages(st } /* + * 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(); + + while(!progress && --retry) { + progress = try_to_free_mem_cgroup_pages(mem, gfp_mask); + } + 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: linux-2.6.26-rc2/mm/shmem.c =================================================================== --- linux-2.6.26-rc2.orig/mm/shmem.c +++ linux-2.6.26-rc2/mm/shmem.c @@ -1314,13 +1314,12 @@ 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; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org