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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2008-07-25 01:47:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 10:53:37 -0700
commite8589cc189f96b87348ae83ea4db38eaac624135 (patch)
tree6693422dc81e6da78c4ad892b0d326fb7f946dda /include/linux/memcontrol.h
parent508b7be0a5b06b64203512ed9b34191cddc83f56 (diff)
downloadop-kernel-dev-e8589cc189f96b87348ae83ea4db38eaac624135.zip
op-kernel-dev-e8589cc189f96b87348ae83ea4db38eaac624135.tar.gz
memcg: better migration handling
This patch changes page migration under memory controller to use a different algorithm. (thanks to Christoph for new idea.) Before: - page_cgroup is migrated from an old page to a new page. After: - a new page is accounted , no reuse of page_cgroup. Pros: - We can avoid compliated lock depndencies and races in migration. Cons: - new param to mem_cgroup_charge_common(). - mem_cgroup_getref() is added for handling ref_cnt ping-pong. This version simplifies complicated lock dependency in page migraiton under memory resource controller. new refcnt sequence is following. a mapped page: prepage_migration() ..... +1 to NEW page try_to_unmap() ..... all refs to OLD page is gone. move_pages() ..... +1 to NEW page if page cache. remap... ..... all refs from *map* is added to NEW one. end_migration() ..... -1 to New page. page's mapcount + (page_is_cache) refs are added to NEW one. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Hugh Dickins <hugh@veritas.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/memcontrol.h')
-rw-r--r--include/linux/memcontrol.h11
1 files changed, 6 insertions, 5 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index e660877..84ead2a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -50,9 +50,10 @@ extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
#define mm_match_cgroup(mm, cgroup) \
((cgroup) == mem_cgroup_from_task((mm)->owner))
-extern int mem_cgroup_prepare_migration(struct page *page);
+extern int
+mem_cgroup_prepare_migration(struct page *page, struct page *newpage);
extern void mem_cgroup_end_migration(struct page *page);
-extern void mem_cgroup_page_migration(struct page *page, struct page *newpage);
+extern int mem_cgroup_getref(struct page *page);
/*
* For memory reclaim.
@@ -112,7 +113,8 @@ static inline int task_in_mem_cgroup(struct task_struct *task,
return 1;
}
-static inline int mem_cgroup_prepare_migration(struct page *page)
+static inline int
+mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
{
return 0;
}
@@ -121,8 +123,7 @@ static inline void mem_cgroup_end_migration(struct page *page)
{
}
-static inline void
-mem_cgroup_page_migration(struct page *page, struct page *newpage)
+static inline void mem_cgroup_getref(struct page *page)
{
}
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