From: Christoph Hellwig <hch@infradead.org>
To: "J. Bruce Fields" <bfields@redhat.com>
Cc: linux-fsdevel@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
Al Viro <viro@ZenIV.linux.org.uk>,
linux-nfs@vger.kernel.org
Subject: Re: simplify reconnecting dentries looked up by filehandle
Date: Wed, 16 Oct 2013 11:24:47 -0700 [thread overview]
Message-ID: <20131016182447.GA3088@infradead.org> (raw)
In-Reply-To: <1381869574-10662-1-git-send-email-bfields@redhat.com>
On Tue, Oct 15, 2013 at 04:39:28PM -0400, J. Bruce Fields wrote:
> I tested performance with a script that creates an N-deep directory
> tree, gets a filehandle for the bottom directory, writes 2 to
> /proc/sys/vm/drop_caches, then times an open_by_handle_at() of the
> filehandle. Code at
>
> git://linux-nfs.org/~bfields/fhtests.git
>
> For directories of various depths, some example observed times (median
> results of 3 similar runs, in seconds), were:
>
> depth: 8000 2000 200
> no patches: 11 0.7 0.02
> first patch: 6 0.4 0.01
> all patches: 0.1 0.03 0.01
>
> For depths < 2000 I used an ugly hack to shrink_slab_node() to force
> drop_caches to free more dentries. Difference look lost in the noise
> for much smaller depths.
Btw, it would be good to get this wired up in xfstests - add xfs_io
commands for the by handle ops and then just wire up the script driving
them.
I'd also really like to see a stress test for cold handle conversion vs
various VFS ops based on that sort of infrastructure.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
Al Viro <viro-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>,
linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: simplify reconnecting dentries looked up by filehandle
Date: Wed, 16 Oct 2013 11:24:47 -0700 [thread overview]
Message-ID: <20131016182447.GA3088@infradead.org> (raw)
In-Reply-To: <1381869574-10662-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
On Tue, Oct 15, 2013 at 04:39:28PM -0400, J. Bruce Fields wrote:
> I tested performance with a script that creates an N-deep directory
> tree, gets a filehandle for the bottom directory, writes 2 to
> /proc/sys/vm/drop_caches, then times an open_by_handle_at() of the
> filehandle. Code at
>
> git://linux-nfs.org/~bfields/fhtests.git
>
> For directories of various depths, some example observed times (median
> results of 3 similar runs, in seconds), were:
>
> depth: 8000 2000 200
> no patches: 11 0.7 0.02
> first patch: 6 0.4 0.01
> all patches: 0.1 0.03 0.01
>
> For depths < 2000 I used an ugly hack to shrink_slab_node() to force
> drop_caches to free more dentries. Difference look lost in the noise
> for much smaller depths.
Btw, it would be good to get this wired up in xfstests - add xfs_io
commands for the by handle ops and then just wire up the script driving
them.
I'd also really like to see a stress test for cold handle conversion vs
various VFS ops based on that sort of infrastructure.
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next prev parent reply other threads:[~2013-10-16 18:24 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-15 20:39 simplify reconnecting dentries looked up by filehandle J. Bruce Fields
2013-10-15 20:39 ` [PATCH 1/5] exportfs: clear DISCONNECTED on all parents sooner J. Bruce Fields
2013-10-16 7:13 ` Christoph Hellwig
2013-10-16 7:13 ` Christoph Hellwig
2013-10-16 13:56 ` J. Bruce Fields
2013-10-16 13:56 ` J. Bruce Fields
2013-10-15 20:39 ` [PATCH 2/5] exportfs: move most of reconnect_path to helper function J. Bruce Fields
2013-10-16 7:16 ` Christoph Hellwig
2013-10-16 7:16 ` Christoph Hellwig
2013-10-15 20:39 ` [PATCH 3/5] exportfs: make variable names more helpful J. Bruce Fields
2013-10-15 20:39 ` J. Bruce Fields
2013-10-16 7:18 ` Christoph Hellwig
2013-10-16 7:18 ` Christoph Hellwig
2013-10-15 20:39 ` [PATCH 4/5] exportfs: slight reorganization of reconnect loop J. Bruce Fields
2013-10-16 7:19 ` Christoph Hellwig
2013-10-15 20:39 ` [PATCH 5/5] exportfs: fix quadratic behavior in filehandle lookup J. Bruce Fields
2013-10-15 20:39 ` J. Bruce Fields
2013-10-16 8:04 ` Christoph Hellwig
2013-10-16 8:04 ` Christoph Hellwig
2013-10-16 18:29 ` J. Bruce Fields
2013-10-16 19:22 ` J. Bruce Fields
2013-10-16 22:00 ` J. Bruce Fields
2013-10-16 18:24 ` Christoph Hellwig [this message]
2013-10-16 18:24 ` simplify reconnecting dentries looked up by filehandle Christoph Hellwig
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