From: Shaohua Li <shaohua.li@intel.com>
To: Mel Gorman <mgorman@suse.de>
Cc: Linux-MM <linux-mm@kvack.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Minchan Kim <minchan.kim@gmail.com>, Jan Kara <jack@suse.cz>,
Andy Isaacson <adi@hexapodia.org>,
Johannes Weiner <jweiner@redhat.com>,
Rik van Riel <riel@redhat.com>, Nai Xia <nai.xia@gmail.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 7/7] mm: compaction: Introduce sync-light migration for use by compaction
Date: Tue, 22 Nov 2011 14:56:51 +0800 [thread overview]
Message-ID: <1321945011.22361.335.camel@sli10-conroe> (raw)
In-Reply-To: <1321900608-27687-8-git-send-email-mgorman@suse.de>
On Tue, 2011-11-22 at 02:36 +0800, Mel Gorman wrote:
> This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
> mode that avoids writing back pages to backing storage. Async
> compaction maps to MIGRATE_ASYNC while sync compaction maps to
> MIGRATE_SYNC_LIGHT. For other migrate_pages users such as memory
> hotplug, MIGRATE_SYNC is used.
>
> This avoids sync compaction stalling for an excessive length of time,
> particularly when copying files to a USB stick where there might be
> a large number of dirty pages backed by a filesystem that does not
> support ->writepages.
Hi,
from my understanding, with this, even writes
to /proc/sys/vm/compact_memory doesn't wait for pageout, is this
intended?
on the other hand, MIGRATE_SYNC_LIGHT now waits for pagelock and buffer
lock, so could wait on page read. page read and page out have the same
latency, why takes them different?
Thanks,
Shaohua
next prev parent reply other threads:[~2011-11-22 6:46 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-21 18:36 [RFC PATCH 0/7] Reduce compaction-related stalls and improve asynchronous migration of dirty pages v4r2 Mel Gorman
2011-11-21 18:36 ` [PATCH 1/7] mm: compaction: Allow compaction to isolate dirty pages Mel Gorman
2011-11-22 16:58 ` Minchan Kim
2011-11-21 18:36 ` [PATCH 2/7] mm: compaction: Use synchronous compaction for /proc/sys/vm/compact_memory Mel Gorman
2011-11-22 17:00 ` Minchan Kim
2011-11-21 18:36 ` [PATCH 3/7] mm: check if we isolated a compound page during lumpy scan Mel Gorman
2011-11-22 17:05 ` Minchan Kim
2011-11-21 18:36 ` [PATCH 4/7] mm: compaction: Determine if dirty pages can be migrated without blocking within ->migratepage Mel Gorman
2011-11-21 18:36 ` [PATCH 5/7] mm: compaction: make isolate_lru_page() filter-aware again Mel Gorman
2011-11-22 17:30 ` Minchan Kim
2011-11-23 9:19 ` Mel Gorman
2011-11-21 18:36 ` [PATCH 6/7] mm: page allocator: Limit when direct reclaim is used when compaction is deferred Mel Gorman
2011-11-22 17:50 ` Minchan Kim
2011-11-21 18:36 ` [PATCH 7/7] mm: compaction: Introduce sync-light migration for use by compaction Mel Gorman
2011-11-22 6:56 ` Shaohua Li [this message]
2011-11-22 10:14 ` Mel Gorman
2011-11-22 11:54 ` Jan Kara
2011-11-22 13:59 ` Nai Xia
2011-11-22 15:07 ` Nai Xia
2011-11-22 19:13 ` Jan Kara
2011-11-22 22:44 ` Nai Xia
2011-11-23 11:39 ` Jan Kara
2011-11-23 12:20 ` Nai Xia
2011-11-23 2:01 ` Nai Xia
2011-11-23 2:25 ` Shaohua Li
2011-11-23 11:00 ` Mel Gorman
2011-11-23 12:51 ` Nai Xia
2011-11-23 13:05 ` Nai Xia
2011-11-23 13:45 ` Mel Gorman
2011-11-23 14:35 ` Nai Xia
2011-11-23 15:08 ` Mel Gorman
2011-11-23 15:23 ` Nai Xia
2011-11-23 15:57 ` Mel Gorman
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