Messages in this thread | | | Date | Fri, 18 Feb 2011 09:14:34 +0900 | Subject | Re: [PATCH v5 2/4] memcg: move memcg reclaimable page into tail of inactive list | From | Minchan Kim <> |
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Hi Kame,
On Fri, Feb 18, 2011 at 1:04 AM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > On Fri, 18 Feb 2011 00:08:20 +0900 > Minchan Kim <minchan.kim@gmail.com> wrote: > >> The rotate_reclaimable_page function moves just written out >> pages, which the VM wanted to reclaim, to the end of the >> inactive list. That way the VM will find those pages first >> next time it needs to free memory. >> This patch apply the rule in memcg. >> It can help to prevent unnecessary working page eviction of memcg. >> >> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> >> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> >> Reviewed-by: Rik van Riel <riel@redhat.com> >> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> >> Cc: Johannes Weiner <hannes@cmpxchg.org> >> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> >> --- >> Changelog since v4: >> - add acked-by and reviewed-by >> - change description - suggested by Rik >> >> include/linux/memcontrol.h | 6 ++++++ >> mm/memcontrol.c | 27 +++++++++++++++++++++++++++ >> mm/swap.c | 3 ++- >> 3 files changed, 35 insertions(+), 1 deletions(-) >> >> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h >> index 3da48ae..5a5ce70 100644 >> --- a/include/linux/memcontrol.h >> +++ b/include/linux/memcontrol.h >> @@ -62,6 +62,7 @@ extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, >> gfp_t gfp_mask); >> extern void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru); >> extern void mem_cgroup_del_lru_list(struct page *page, enum lru_list lru); >> +extern void mem_cgroup_rotate_reclaimable_page(struct page *page); >> extern void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru); >> extern void mem_cgroup_del_lru(struct page *page); >> extern void mem_cgroup_move_lists(struct page *page, >> @@ -215,6 +216,11 @@ static inline void mem_cgroup_del_lru_list(struct page *page, int lru) >> return ; >> } >> >> +static inline inline void mem_cgroup_rotate_reclaimable_page(struct page *page) >> +{ >> + return ; >> +} >> + >> static inline void mem_cgroup_rotate_lru_list(struct page *page, int lru) >> { >> return ; >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 686f1ce..ab8bdff 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -813,6 +813,33 @@ void mem_cgroup_del_lru(struct page *page) >> mem_cgroup_del_lru_list(page, page_lru(page)); >> } >> >> +/* >> + * Writeback is about to end against a page which has been marked for immediate >> + * reclaim. If it still appears to be reclaimable, move it to the tail of the >> + * inactive list. >> + */ >> +void mem_cgroup_rotate_reclaimable_page(struct page *page) >> +{ >> + struct mem_cgroup_per_zone *mz; >> + struct page_cgroup *pc; >> + enum lru_list lru = page_lru_base_type(page); >> + >> + if (mem_cgroup_disabled()) >> + return; >> + >> + pc = lookup_page_cgroup(page); >> + /* >> + * Used bit is set without atomic ops but after smp_wmb(). >> + * For making pc->mem_cgroup visible, insert smp_rmb() here. >> + */ >> + smp_rmb(); >> + /* unused or root page is not rotated. */ >> + if (!PageCgroupUsed(pc) || mem_cgroup_is_root(pc->mem_cgroup)) >> + return; >> + mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); >> + list_move_tail(&pc->lru, &mz->lists[lru]); >> +} >> + > > Hmm, I'm sorry I misunderstand this. IIUC, page_lru_base_type() always returns > LRU_INACTIVE_XXX and this function may move page from active LRU to inactive LRU. > > Then, LRU counters for memcg should be updated.
Goal of mem_cgroup_rotate_reclaimable_page is same with rotate_reclaimable_page. It means the page was already in inactive list. Look at the check !PageActive(page).
But if you want to make the function generally(ie, support active->inactive, too), I don't mind it. but if you want it, let's make rotate_reclaimable_page to general function, too. but now any user doesn't use it.
Thanks for the careful review.
> > Could you replace after lookup like this ? > > VM_BUG_ON(!PageCgroupAcctLRU(pc)) /* Implies this pages must be on some LRU */ > if (!PageCgroupUsed(pc)) > return; > /* Used bit check is not necessary, because there is a case Unused page > is lazily on LRU. We trust AcctLRU bit. */ > mz = page_cgroup_zoneinfo(pc->mem_cgroup, page); > MEM_CGROUP_ZSTAT(mz, page_lru(page)) -= 1 << compound_order(page); > MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page) > if (mem_cgroup_is_root(pc->mem_cgroup)) > return; > list_move_tail(&pc->lru, &mz->lists[lru]) > > > Thanks, > -Kame >> void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru) >> { >> struct mem_cgroup_per_zone *mz; >> diff --git a/mm/swap.c b/mm/swap.c >> index 4aea806..1b9e4eb 100644 >> --- a/mm/swap.c >> +++ b/mm/swap.c >> @@ -200,8 +200,9 @@ static void pagevec_move_tail(struct pagevec *pvec) >> spin_lock(&zone->lru_lock); >> } >> if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { >> - int lru = page_lru_base_type(page); >> + enum lru_list lru = page_lru_base_type(page); >> list_move_tail(&page->lru, &zone->lru[lru].list); >> + mem_cgroup_rotate_reclaimable_page(page); >> pgmoved++; >> } >> } >> -- >> 1.7.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ >> > >
-- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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