From: Minchan Kim <minchan@kernel.org>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Dave Chinner <david@fromorbit.com>,
Rik van Riel <riel@redhat.com>, Jan Kara <jack@suse.cz>,
Vlastimil Babka <vbabka@suse.cz>,
Peter Zijlstra <peterz@infradead.org>, Tejun Heo <tj@kernel.org>,
Andi Kleen <andi@firstfloor.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Greg Thelen <gthelen@google.com>,
Christoph Hellwig <hch@infradead.org>,
Hugh Dickins <hughd@google.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Mel Gorman <mgorman@suse.de>,
Michel Lespinasse <walken@google.com>,
Seth Jennings <sjenning@linux.vnet.ibm.com>,
Roman Gushchin <klamm@yandex-team.ru>,
Ozgun Erdogan <ozgun@citusdata.com>,
Metin Doslu <metin@citusdata.com>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [patch 3/9] mm: shmem: save one radix tree lookup when truncating swapped pages
Date: Mon, 25 Nov 2013 17:21:52 +0900 [thread overview]
Message-ID: <20131125082152.GC4731@bbox> (raw)
In-Reply-To: <1385336308-27121-4-git-send-email-hannes@cmpxchg.org>
On Sun, Nov 24, 2013 at 06:38:22PM -0500, Johannes Weiner wrote:
> Page cache radix tree slots are usually stabilized by the page lock,
> but shmem's swap cookies have no such thing. Because the overall
> truncation loop is lockless, the swap entry is currently confirmed by
> a tree lookup and then deleted by another tree lookup under the same
> tree lock region.
>
> Use radix_tree_delete_item() instead, which does the verification and
> deletion with only one lookup. This also allows removing the
> delete-only special case from shmem_radix_tree_replace().
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Nice cleanup!
--
Kind regards,
Minchan Kim
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WARNING: multiple messages have this Message-ID (diff)
From: Minchan Kim <minchan@kernel.org>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Dave Chinner <david@fromorbit.com>,
Rik van Riel <riel@redhat.com>, Jan Kara <jack@suse.cz>,
Vlastimil Babka <vbabka@suse.cz>,
Peter Zijlstra <peterz@infradead.org>, Tejun Heo <tj@kernel.org>,
Andi Kleen <andi@firstfloor.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Greg Thelen <gthelen@google.com>,
Christoph Hellwig <hch@infradead.org>,
Hugh Dickins <hughd@google.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Mel Gorman <mgorman@suse.de>,
Michel Lespinasse <walken@google.com>,
Seth Jennings <sjenning@linux.vnet.ibm.com>,
Roman Gushchin <klamm@yandex-team.ru>,
Ozgun Erdogan <ozgun@citusdata.com>,
Metin Doslu <metin@citusdata.com>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [patch 3/9] mm: shmem: save one radix tree lookup when truncating swapped pages
Date: Mon, 25 Nov 2013 17:21:52 +0900 [thread overview]
Message-ID: <20131125082152.GC4731@bbox> (raw)
In-Reply-To: <1385336308-27121-4-git-send-email-hannes@cmpxchg.org>
On Sun, Nov 24, 2013 at 06:38:22PM -0500, Johannes Weiner wrote:
> Page cache radix tree slots are usually stabilized by the page lock,
> but shmem's swap cookies have no such thing. Because the overall
> truncation loop is lockless, the swap entry is currently confirmed by
> a tree lookup and then deleted by another tree lookup under the same
> tree lock region.
>
> Use radix_tree_delete_item() instead, which does the verification and
> deletion with only one lookup. This also allows removing the
> delete-only special case from shmem_radix_tree_replace().
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Nice cleanup!
--
Kind regards,
Minchan Kim
next prev parent reply other threads:[~2013-11-25 8:21 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-24 23:38 [patch 0/9] mm: thrash detection-based file cache sizing v6 Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-24 23:38 ` [patch 1/9] fs: cachefiles: use add_to_page_cache_lru() Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-24 23:38 ` [patch 2/9] lib: radix-tree: radix_tree_delete_item() Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-25 8:21 ` Minchan Kim
2013-11-25 8:21 ` Minchan Kim
2013-11-24 23:38 ` [patch 3/9] mm: shmem: save one radix tree lookup when truncating swapped pages Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-25 8:21 ` Minchan Kim [this message]
2013-11-25 8:21 ` Minchan Kim
2013-11-24 23:38 ` [patch 4/9] mm: filemap: move radix tree hole searching here Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-24 23:38 ` [patch 5/9] mm + fs: prepare for non-page entries in page cache radix trees Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-24 23:38 ` [patch 6/9] mm + fs: store shadow entries in page cache Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-25 23:17 ` Dave Chinner
2013-11-25 23:17 ` Dave Chinner
2013-11-26 10:20 ` Peter Zijlstra
2013-11-26 10:20 ` Peter Zijlstra
2013-11-27 16:45 ` Johannes Weiner
2013-11-27 16:45 ` Johannes Weiner
2013-11-27 17:08 ` Johannes Weiner
2013-11-27 17:08 ` Johannes Weiner
2013-11-27 23:32 ` Dave Chinner
2013-11-27 23:32 ` Dave Chinner
2013-11-24 23:38 ` [patch 7/9] mm: thrash detection-based file cache sizing Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-25 23:50 ` Andrew Morton
2013-11-25 23:50 ` Andrew Morton
2013-11-26 2:15 ` Johannes Weiner
2013-11-26 2:15 ` Johannes Weiner
2013-11-26 1:56 ` Ryan Mallon
2013-11-26 1:56 ` Ryan Mallon
2013-11-26 20:57 ` Johannes Weiner
2013-11-26 20:57 ` Johannes Weiner
2013-11-24 23:38 ` [patch 8/9] lib: radix_tree: tree node interface Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-24 23:38 ` [patch 9/9] mm: keep page cache radix tree nodes in check Johannes Weiner
2013-11-24 23:38 ` Johannes Weiner
2013-11-25 23:49 ` Dave Chinner
2013-11-25 23:49 ` Dave Chinner
2013-11-26 21:27 ` Johannes Weiner
2013-11-26 21:27 ` Johannes Weiner
2013-11-26 22:29 ` Dave Chinner
2013-11-26 22:29 ` Dave Chinner
2013-11-26 23:00 ` Johannes Weiner
2013-11-26 23:00 ` Johannes Weiner
2013-11-27 0:59 ` Dave Chinner
2013-11-27 0:59 ` Dave Chinner
2013-11-26 0:13 ` Andrew Morton
2013-11-26 0:13 ` Andrew Morton
2013-11-26 22:05 ` Johannes Weiner
2013-11-26 22:05 ` Johannes Weiner
2013-11-26 0:57 ` [patch 0/9] mm: thrash detection-based file cache sizing v6 Andrew Morton
2013-11-26 0:57 ` Andrew Morton
2013-11-26 22:30 ` Johannes Weiner
2013-11-26 22:30 ` Johannes Weiner
2013-11-28 4:40 ` Johannes Weiner
2013-11-28 4:40 ` Johannes Weiner
-- strict thread matches above, loose matches on Subject: below --
2013-12-02 19:21 [patch 0/9] mm: thrash detection-based file cache sizing v7 Johannes Weiner
2013-12-02 19:21 ` [patch 3/9] mm: shmem: save one radix tree lookup when truncating swapped pages Johannes Weiner
2013-12-02 19:21 ` Johannes Weiner
2014-01-10 18:10 [patch 0/9] mm: thrash detection-based file cache sizing v8 Johannes Weiner
2014-01-10 18:10 ` [patch 3/9] mm: shmem: save one radix tree lookup when truncating swapped pages Johannes Weiner
2014-01-10 18:10 ` Johannes Weiner
2014-01-10 18:25 ` Rik van Riel
2014-01-10 18:25 ` Rik van Riel
2014-01-10 18:25 ` Rik van Riel
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