From: Rik van Riel <riel@redhat.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>,
Johannes Weiner <hannes@cmpxchg.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] vmscan,tmpfs: treat used once pages on tmpfs as used once
Date: Wed, 01 Sep 2010 09:51:14 -0400 [thread overview]
Message-ID: <4C7E5A52.7080806@redhat.com> (raw)
In-Reply-To: <20100901103653.974C.A69D9226@jp.fujitsu.com>
On 08/31/2010 09:37 PM, KOSAKI Motohiro wrote:
> When a page has PG_referenced, shrink_page_list() discard it only
> if it is no dirty. This rule works completely fine if the backend
> filesystem is regular one. PG_dirty is good signal that it was used
> recently because flusher thread clean pages periodically. In addition,
> page writeback is costly rather than simple page discard.
>
> However, When a page is on tmpfs, this heuristic don't works because
> flusher thread don't writeback tmpfs pages. then, tmpfs pages always
> rotate lru twice at least and it makes unnecessary lru churn. Merely
> tmpfs streaming io shouldn't cause large anonymous page swap-out.
>
> This patch remove this unncessary reclaim bonus of tmpfs pages.
>
> Cc: Hugh Dickins<hughd@google.com>
> Cc: Johannes Weiner<hannes@cmpxchg.org>
> Cc: Rik van Riel<riel@redhat.com>
> Signed-off-by: KOSAKI Motohiro<kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
--
All rights reversed
WARNING: multiple messages have this Message-ID (diff)
From: Rik van Riel <riel@redhat.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>,
Johannes Weiner <hannes@cmpxchg.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] vmscan,tmpfs: treat used once pages on tmpfs as used once
Date: Wed, 01 Sep 2010 09:51:14 -0400 [thread overview]
Message-ID: <4C7E5A52.7080806@redhat.com> (raw)
In-Reply-To: <20100901103653.974C.A69D9226@jp.fujitsu.com>
On 08/31/2010 09:37 PM, KOSAKI Motohiro wrote:
> When a page has PG_referenced, shrink_page_list() discard it only
> if it is no dirty. This rule works completely fine if the backend
> filesystem is regular one. PG_dirty is good signal that it was used
> recently because flusher thread clean pages periodically. In addition,
> page writeback is costly rather than simple page discard.
>
> However, When a page is on tmpfs, this heuristic don't works because
> flusher thread don't writeback tmpfs pages. then, tmpfs pages always
> rotate lru twice at least and it makes unnecessary lru churn. Merely
> tmpfs streaming io shouldn't cause large anonymous page swap-out.
>
> This patch remove this unncessary reclaim bonus of tmpfs pages.
>
> Cc: Hugh Dickins<hughd@google.com>
> Cc: Johannes Weiner<hannes@cmpxchg.org>
> Cc: Rik van Riel<riel@redhat.com>
> Signed-off-by: KOSAKI Motohiro<kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
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All rights reversed
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next prev parent reply other threads:[~2010-09-01 13:51 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-01 1:37 [PATCH] vmscan,tmpfs: treat used once pages on tmpfs as used once KOSAKI Motohiro
2010-09-01 1:37 ` KOSAKI Motohiro
2010-09-01 9:30 ` Johannes Weiner
2010-09-01 9:30 ` Johannes Weiner
2010-09-01 13:51 ` Rik van Riel [this message]
2010-09-01 13:51 ` Rik van Riel
2010-09-02 9:56 ` Minchan Kim
2010-09-02 9:56 ` Minchan Kim
2010-09-02 10:04 ` KOSAKI Motohiro
2010-09-02 10:04 ` KOSAKI Motohiro
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