From: Dave Chinner <david@fromorbit.com>
To: Nick Piggin <npiggin@suse.de>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, xfs@oss.sgi.com
Subject: Re: [PATCH 3/5] superblock: introduce per-sb cache shrinker infrastructure
Date: Thu, 27 May 2010 14:07:04 +1000 [thread overview]
Message-ID: <20100527040704.GJ12087@dastard> (raw)
In-Reply-To: <20100527021905.GG22536@laptop>
On Thu, May 27, 2010 at 12:19:05PM +1000, Nick Piggin wrote:
> On Thu, May 27, 2010 at 09:12:14AM +1000, Dave Chinner wrote:
> > On Thu, May 27, 2010 at 02:41:16AM +1000, Nick Piggin wrote:
> > > > + count = ((sb->s_nr_dentry_unused + sb->s_nr_inodes_unused) / 100)
> > > > + * sysctl_vfs_cache_pressure;
> > >
> > > Do you think truncating in the divisions is at all a problem? It
> > > probably doesn't matter much I suppose.
> >
> > Same code as currently exists. IIRC, the reasoning is that if we've
> > got less that 100 objects to reclaim, then we're unlikely to be able
> > to free up any memory from the caches, anyway.
>
> Yeah, which is why I stop short of saying you should change it in
> this patch.
>
> But I think we should ensure things can get reclaimed eventually.
> 100 objects could be 100 slabs, which could be anything from
> half a meg to half a dozen. Multiplied by each of the caches.
> Could be significant in small systems.
True, but usually there are busy objects in the dentry and inode
slabs, so it shouldn't be a significant issue. We can probably
address such problems if they can be demonstrated to be an issue in
a separate patch set....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
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next prev parent reply other threads:[~2010-05-27 4:07 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-25 8:53 [PATCH 0/5] Per superblock shrinkers V2 Dave Chinner
2010-05-25 8:53 ` [PATCH 1/5] inode: Make unused inode LRU per superblock Dave Chinner
2010-05-26 16:17 ` Nick Piggin
2010-05-26 23:01 ` Dave Chinner
2010-05-27 2:04 ` Nick Piggin
2010-05-27 4:02 ` Dave Chinner
2010-05-27 4:23 ` Nick Piggin
2010-05-27 20:32 ` Andrew Morton
2010-05-27 22:54 ` Dave Chinner
2010-05-28 10:07 ` Nick Piggin
2010-05-25 8:53 ` [PATCH 2/5] mm: add context argument to shrinker callback Dave Chinner
2010-05-25 8:53 ` [PATCH 3/5] superblock: introduce per-sb cache shrinker infrastructure Dave Chinner
2010-05-26 16:41 ` Nick Piggin
2010-05-26 23:12 ` Dave Chinner
2010-05-27 1:53 ` [PATCH 3/5 v2] " Dave Chinner
2010-05-27 4:01 ` Al Viro
2010-05-27 6:17 ` Dave Chinner
2010-05-27 6:46 ` Nick Piggin
2010-05-27 2:19 ` [PATCH 3/5] " Nick Piggin
2010-05-27 4:07 ` Dave Chinner [this message]
2010-05-27 4:24 ` Nick Piggin
2010-05-27 6:35 ` Nick Piggin
2010-05-27 22:40 ` Dave Chinner
2010-05-28 5:19 ` Nick Piggin
2010-05-31 6:39 ` Dave Chinner
2010-05-31 7:28 ` Nick Piggin
2010-05-27 20:32 ` Andrew Morton
2010-05-27 23:01 ` Dave Chinner
2010-05-25 8:53 ` [PATCH 4/5] superblock: add filesystem shrinker operations Dave Chinner
2010-05-27 20:32 ` Andrew Morton
2010-05-25 8:53 ` [PATCH 5/5] xfs: make use of new shrinker callout Dave Chinner
2010-05-26 16:44 ` [PATCH 0/5] Per superblock shrinkers V2 Nick Piggin
2010-05-27 20:32 ` Andrew Morton
2010-05-28 0:30 ` Dave Chinner
2010-05-28 7:42 ` Artem Bityutskiy
2010-07-02 12:13 ` Christoph Hellwig
2010-07-12 2:41 ` Dave Chinner
2010-07-12 2:52 ` Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2010-05-14 7:24 [PATCH 0/5] Per-superblock shrinkers Dave Chinner
2010-05-14 7:24 ` [PATCH 3/5] superblock: introduce per-sb cache shrinker infrastructure Dave Chinner
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