From: Rik van Riel <riel@redhat.com>
To: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Eric Whitney <eric.whitney@hp.com>
Subject: Re: [patch 00/19] VM pageout scalability improvements
Date: Thu, 3 Jan 2008 17:00:35 -0500 [thread overview]
Message-ID: <20080103170035.105d22c8@cuia.boston.redhat.com> (raw)
In-Reply-To: <1199380412.5295.29.camel@localhost>
On Thu, 03 Jan 2008 12:13:32 -0500
Lee Schermerhorn <Lee.Schermerhorn@hp.com> wrote:
> Yes, but the problem, when it occurs, is very awkward. The system just
> hangs for hours/days spinning on the reverse mapping locks--in both
> page_referenced() and try_to_unmap(). No pages get reclaimed and NO OOM
> kill occurs because we never get that far. So, I'm not sure I'd call
> any OOM kills resulting from this patch as "false". The memory is
> effectively nonreclaimable. Now, I think that your anon pages SEQ
> patch will eliminate the contention in page_referenced[_anon](), but we
> could still hang in try_to_unmap().
I am hoping that Nick's ticket spinlocks will fix this problem.
Would you happen to have any test cases for the above problem that
I could use to reproduce the problem and look for an automatic fix?
Any fix that requires the sysadmin to tune things _just_ right seems
too dangerous to me - especially if a change in the workload can
result in the system doing exactly the wrong thing...
The idea is valid, but it just has to work automagically.
Btw, if page_referenced() is called less, the locks that try_to_unmap()
also takes should get less contention.
--
All Rights Reversed
next prev parent reply other threads:[~2008-01-03 22:01 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-02 22:41 [patch 00/19] VM pageout scalability improvements linux-kernel
2008-01-02 22:41 ` [patch 01/19] move isolate_lru_page() to vmscan.c linux-kernel
2008-01-02 22:41 ` [patch 02/19] free swap space on swap-in/activation linux-kernel
2008-01-02 22:41 ` [patch 03/19] define page_file_cache() function linux-kernel
2008-01-02 22:41 ` [patch 04/19] debugging checks for page_file_cache() linux-kernel
2008-01-02 22:41 ` [patch 05/19] Use an indexed array for LRU variables linux-kernel
2008-01-02 22:41 ` [patch 06/19] split LRU lists into anon & file sets linux-kernel
2008-01-07 9:23 ` KAMEZAWA Hiroyuki
2008-01-02 22:41 ` [patch 07/19] split anon & file LRUs for memcontrol code linux-kernel
2008-01-07 10:04 ` KAMEZAWA Hiroyuki
2008-01-07 14:10 ` Balbir Singh
2008-01-07 15:23 ` Rik van Riel
2008-01-02 22:41 ` [patch 08/19] SEQ replacement for anonymous pages linux-kernel
2008-01-02 22:41 ` [patch 09/19] add newly swapped in pages to the inactive list linux-kernel
2008-01-02 22:41 ` [patch 10/19] No Reclaim LRU Infrastructure linux-kernel
2008-01-02 22:41 ` [patch 11/19] Non-reclaimable page statistics linux-kernel
2008-01-02 22:41 ` [patch 12/19] scan noreclaim list for reclaimable pages linux-kernel
2008-01-02 22:41 ` [patch 13/19] ramfs pages are non-reclaimable linux-kernel
2008-01-02 22:41 ` [patch 14/19] SHM_LOCKED pages are nonreclaimable linux-kernel
2008-01-02 22:41 ` [patch 15/19] non-reclaimable mlocked pages linux-kernel
2008-01-02 22:42 ` [patch 16/19] mlock vma pages under mmap_sem held for read linux-kernel
2008-01-02 22:42 ` [patch 17/19] handle mlocked pages during map/unmap and truncate linux-kernel
2008-01-02 22:42 ` [patch 18/19] account mlocked pages linux-kernel
2008-01-02 22:42 ` [patch 19/19] cull non-reclaimable anon pages from the LRU at fault time linux-kernel
2008-01-03 16:52 ` [patch 00/19] VM pageout scalability improvements Lee Schermerhorn
2008-01-03 17:00 ` Rik van Riel
2008-01-03 17:13 ` Lee Schermerhorn
2008-01-03 22:00 ` Rik van Riel [this message]
2008-01-04 16:25 ` Lee Schermerhorn
2008-01-04 16:34 ` Andi Kleen
2008-01-04 16:55 ` Rik van Riel
2008-01-04 18:07 ` Larry Woodman
2008-01-04 17:06 ` Lee Schermerhorn
2008-01-07 19:07 ` Christoph Lameter
2008-01-07 19:32 ` Rik van Riel
2008-01-07 10:06 ` KAMEZAWA Hiroyuki
2008-01-07 15:18 ` Rik van Riel
2008-01-08 20:59 Rik van Riel
2008-01-10 4:39 ` Mike Snitzer
2008-01-10 15:41 ` Rik van Riel
2008-01-10 16:08 ` Mike Snitzer
2008-01-11 10:41 ` Balbir Singh
2008-01-11 15:38 ` Rik van Riel
2008-01-11 11:47 ` Balbir Singh
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