Messages in this thread Patch in this message | | | From | KOSAKI Motohiro <> | Subject | [PATCH] mark_page_accessed() in do_swap_page() move latter than memcg charge | Date | Thu, 15 Jan 2009 20:08:36 +0900 (JST) |
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sorry for late responce.
> > In this case we've hit a case where the page is valid and the pc is > > not. This does fix the problem, but won't this impact us getting > > correct reclaim stats and thus indirectly impact the working of > > pressure? > > > - If retruns NULL, only global LRU's status is updated. > > Because this page is not belongs to any memcg, we cannot update > any counters. But yes, your point is a concern. > > Maybe moving acitvate_page() to > == > do_swap_page() > { > > - activate_page() > mem_cgroup_try_charge().. > .... > mem_cgroup_commit_charge().... > .... > + activate_page() > } > == > is necessary. How do you think, kosaki ?
OK. it makes sense. and my test found no bug.
==
mark_page_accessed() update reclaim_stat statics. but currently, memcg charge is called after mark_page_accessed().
then, mark_page_accessed() don't update memcg statics correctly.
fixing here.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
--- mm/memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
Index: b/mm/memory.c =================================================================== --- a/mm/memory.c +++ b/mm/memory.c @@ -2426,8 +2426,6 @@ static int do_swap_page(struct mm_struct count_vm_event(PGMAJFAULT); } - mark_page_accessed(page); - lock_page(page); delayacct_clear_flag(DELAYACCT_PF_SWAPIN); @@ -2480,6 +2478,8 @@ static int do_swap_page(struct mm_struct try_to_free_swap(page); unlock_page(page); + mark_page_accessed(page); + if (write_access) { ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte); if (ret & VM_FAULT_ERROR)
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