From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: axboe@kernel.dk, lucho@ionkov.net, jack@suse.cz,
ericvh@gmail.com, viro@zeniv.linux.org.uk, rminnich@sandia.gov,
tytso@mit.edu, martin.petersen@oracle.com, neilb@suse.de,
david@fromorbit.com, Zheng Liu <gnehzuil.liu@gmail.com>,
linux-kernel@vger.kernel.org, hch@infradead.org,
linux-fsdevel@vger.kernel.org, adilger.kernel@dilger.ca,
bharrosh@panasas.com, jlayton@samba.org,
v9fs-developer@lists.sourceforge.net, linux-ext4@vger.kernel.org
Subject: Re: [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write
Date: Mon, 17 Dec 2012 14:54:35 -0800 [thread overview]
Message-ID: <20121217225435.GA10874@blackbox.djwong.org> (raw)
In-Reply-To: <CALCETrVJd86oD=p6vnRVp=0g8JDbhfZTH2G-ZCCOHzrMMiembw@mail.gmail.com>
On Fri, Dec 14, 2012 at 06:06:50PM -0800, Andy Lutomirski wrote:
> On Fri, Dec 14, 2012 at 6:01 PM, Darrick J. Wong
> <darrick.wong@oracle.com> wrote:
> > On Fri, Dec 14, 2012 at 05:12:37PM -0800, Andy Lutomirski wrote:
> >> It survived. I hit at least one mm bug, but I really don't think it's
> >> a problem with your code. (I have not tried this workload on Linux
> >> 3.7 at all before. It normally runs on 3.5.) The box in question is
> >
> > Would you mind sending along the bug report so I can make sure?
>
> http://marc.info/?l=linux-mm&m=135553342803210&w=2
Hm, this looks like a hugepages thing, which (afaik) doesn't touch fs code at
all. Looks like this patchset is in the clear.
> >
> >> ext4 on LVM on dm-crypt on (hardware) RAID 5 on hpsa, which should not
> >> need stable pages.
> >>
> >> The majority of the data written (that wasn't unlinked before it was
> >> dropped from cache) was checksummed when written and verified later.
> >> Most of this data was written using mmap. This workload hammers the
> >> vm concurrently in several threads, and it frequently stalls when
> >> stable pages are enabled, so it's probably exercising the code
> >> decently well.
> >
> > Did you observe any change in performance?
>
> No. But I'm comparing to 3.5 + butchery to remove stable pages. With
> stable pages on, this workload performs terribly. (It's a soft
> real-time thing, as you can possibly guess from my domain name, and
> various latency monitoring things go nuts when stable pages are
> active.)
Well, I guess that's good. :)
> Actually, performance appears to be improved, probably due to
> https://lkml.org/lkml/2012/12/14/14, which I tested concurrently.
>
> >
> >> Feel free to add Tested-by: Andy Lutomirski <luto@amacapital.net>
> >
> > Will do! Thanks for the testing!
>
> My pleasure. When these changes go in to an upstream kernel, they'll
> represent a significant reduction in how much our kernel differs from
> kernel.org's :) Thanks for fixing this.
No problem!
--D
next prev parent reply other threads:[~2012-12-17 22:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-13 8:07 [PATCH v2.3 0/3] mm/fs: Implement faster stable page writes on filesystems Darrick J. Wong
2012-12-13 8:07 ` [PATCH 1/4] bdi: Allow block devices to say that they require stable page writes Darrick J. Wong
2012-12-17 9:04 ` Jan Kara
2012-12-13 8:07 ` [PATCH 2/4] mm: Only enforce stable page writes if the backing device requires it Darrick J. Wong
2012-12-17 9:16 ` Jan Kara
2012-12-13 8:08 ` [PATCH 3/4] 9pfs: Fix filesystem to wait for stable page writeback Darrick J. Wong
2012-12-17 10:11 ` Jan Kara
2012-12-13 8:08 ` [PATCH 4/4] block: Optionally snapshot page contents to provide stable pages during write Darrick J. Wong
2012-12-14 1:48 ` Andy Lutomirski
2012-12-14 2:10 ` Darrick J. Wong
2012-12-14 3:33 ` Dave Chinner
2012-12-14 19:43 ` Darrick J. Wong
2012-12-15 1:12 ` Andy Lutomirski
2012-12-15 2:01 ` Darrick J. Wong
2012-12-15 2:06 ` Andy Lutomirski
2012-12-17 22:54 ` Darrick J. Wong [this message]
2012-12-16 16:13 ` Zheng Liu
2012-12-17 22:56 ` Darrick J. Wong
2012-12-17 10:23 ` Jan Kara
2012-12-17 23:20 ` Darrick J. Wong
2012-12-27 19:14 ` OGAWA Hirofumi
2012-12-27 21:40 ` Darrick J. Wong
2012-12-27 21:48 ` OGAWA Hirofumi
2013-01-07 20:44 ` Darrick J. Wong
2013-01-08 9:44 ` OGAWA Hirofumi
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