From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
Johannes Weiner <jweiner@redhat.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 5/7] mm: rework reclaim_stat counters
Date: Fri, 9 Mar 2012 10:32:31 +0900 [thread overview]
Message-ID: <20120309103231.03097798.kamezawa.hiroyu@jp.fujitsu.com> (raw)
In-Reply-To: <20120308180419.27621.88710.stgit@zurg>
On Thu, 08 Mar 2012 22:04:19 +0400
Konstantin Khlebnikov <khlebnikov@openvz.org> wrote:
> Currently there is two types of reclaim-stat counters:
> recent_scanned (pages picked from from lru),
> recent_rotated (pages putted back to active lru).
> Reclaimer uses ratio recent_rotated / recent_scanned
> for balancing pressure between file and anon pages.
>
> But if we pick page from lru we can either reclaim it or put it back to lru, thus:
> recent_scanned == recent_rotated[inactive] + recent_rotated[active] + reclaimed
> This can be called "The Law of Conservation of Memory" =)
>
> Thus recent_rotated counters for each lru list is enough, reclaimed pages can be
> counted as rotatation into inactive lru. After that reclaimer can use this ratio:
> recent_rotated[active] / (recent_rotated[active] + recent_rotated[inactive])
>
> After this patch struct zone_reclaimer_stat has only one array: recent_rotated,
> which is directly indexed by lru list index:
>
> before patch:
>
> LRU_ACTIVE_ANON -> LRU_ACTIVE_ANON : recent_scanned[ANON]++, recent_rotated[ANON]++
> LRU_INACTIVE_ANON -> LRU_ACTIVE_ANON : recent_scanned[ANON]++, recent_rotated[ANON]++
> LRU_ACTIVE_ANON -> LRU_INACTIVE_ANON : recent_scanned[ANON]++
> LRU_INACTIVE_ANON -> LRU_INACTIVE_ANON : recent_scanned[ANON]++
>
> after patch:
>
> LRU_ACTIVE_ANON -> LRU_ACTIVE_ANON : recent_rotated[LRU_ACTIVE_ANON]++
> LRU_INACTIVE_ANON -> LRU_ACTIVE_ANON : recent_rotated[LRU_ACTIVE_ANON]++
> LRU_ACTIVE_ANON -> LRU_INACTIVE_ANON : recent_rotated[LRU_INACTIVE_ANON]++
> LRU_INACTIVE_ANON -> LRU_INACTIVE_ANON : recent_rotated[LRU_INACTIVE_ANON]++
>
> recent_scanned[ANON] === recent_rotated[LRU_ACTIVE_ANON] + recent_rotated[LRU_INACTIVE_ANON]
> recent_rotated[ANON] === recent_rotated[LRU_ACTIVE_ANON]
>
> (and the same for FILE/LRU_ACTIVE_FILE/LRU_INACTIVE_FILE)
>
> v5:
> * resolve conflict with "memcg: fix GPF when cgroup removal races with last exit"
>
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Nice description.
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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next prev parent reply other threads:[~2012-03-09 1:34 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-08 18:03 [PATCH v5 0/7] mm: some cleanup/rework before lru_lock splitting Konstantin Khlebnikov
2012-03-08 18:04 ` [PATCH v5 1/7] mm/memcg: scanning_global_lru means mem_cgroup_disabled Konstantin Khlebnikov
2012-03-09 1:26 ` KAMEZAWA Hiroyuki
2012-03-08 18:04 ` [PATCH v5 2/7] mm/memcg: move reclaim_stat into lruvec Konstantin Khlebnikov
2012-03-09 1:27 ` KAMEZAWA Hiroyuki
2012-03-08 18:04 ` [PATCH v5 3/7] mm: push lru index into shrink_[in]active_list() Konstantin Khlebnikov
2012-03-09 1:28 ` KAMEZAWA Hiroyuki
2012-03-08 18:04 ` [PATCH v5 4/7] mm: rework __isolate_lru_page() page lru filter Konstantin Khlebnikov
2012-03-09 1:30 ` KAMEZAWA Hiroyuki
2012-03-08 18:04 ` [PATCH v5 5/7] mm: rework reclaim_stat counters Konstantin Khlebnikov
2012-03-09 1:32 ` KAMEZAWA Hiroyuki [this message]
2012-03-08 18:04 ` [PATCH v5 6/7] mm/memcg: rework inactive_ratio calculation Konstantin Khlebnikov
2012-03-08 18:04 ` [PATCH v5 7/7] mm/memcg: use vm_swappiness from target memory cgroup Konstantin Khlebnikov
2012-03-09 1:33 ` KAMEZAWA Hiroyuki
2012-03-11 14:36 ` [PATCH v5 4.5/7] mm: optimize isolate_lru_pages() Konstantin Khlebnikov
2012-03-13 5:26 ` KAMEZAWA Hiroyuki
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