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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>,
	"Huang, Ying" <ying.huang@intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Bob Peterson <rpeterso@redhat.com>,
	Wu Fengguang <fengguang.wu@intel.com>, LKP <lkp@01.org>
Subject: Re: [LKP] [lkp] [xfs] 68a9f5e700: aim7.jobs-per-min -13.6% regression
Date: Thu, 11 Aug 2016 20:20:53 -0700	[thread overview]
Message-ID: <CA+55aFyhrDXK00mkAdLiXZVy-8=2U2WtRMwPYFF8z-JDwzuodQ@mail.gmail.com> (raw)
In-Reply-To: <20160812025218.GB975@lst.de>

On Thu, Aug 11, 2016 at 7:52 PM, Christoph Hellwig <hch@lst.de> wrote:
>
> I can look at that, but indeed optimizing this patch seems a bit
> stupid.

The "write less than a full block to the end of the file" is actually
a reasonably common case.

It may not make for a great filesystem benchmark, but it also isn't
actually insane. People who do logging in user space do this all the
time, for example. And it is *not* stupid in that context. Not at all.

It's never going to be the *main* thing you do (unless you're AIM),
but I do think it's worth fixing.

And AIM7 remains one of those odd benchmarks that people use. I'm not
quite sure why, but I really do think that the normal "append smaller
chunks to the end of the file" should absolutely not be dismissed as
stupid.

                Linus

WARNING: multiple messages have this Message-ID (diff)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: lkp@lists.01.org
Subject: Re: [xfs] 68a9f5e700: aim7.jobs-per-min -13.6% regression
Date: Thu, 11 Aug 2016 20:20:53 -0700	[thread overview]
Message-ID: <CA+55aFyhrDXK00mkAdLiXZVy-8=2U2WtRMwPYFF8z-JDwzuodQ@mail.gmail.com> (raw)
In-Reply-To: <20160812025218.GB975@lst.de>

[-- Attachment #1: Type: text/plain, Size: 821 bytes --]

On Thu, Aug 11, 2016 at 7:52 PM, Christoph Hellwig <hch@lst.de> wrote:
>
> I can look at that, but indeed optimizing this patch seems a bit
> stupid.

The "write less than a full block to the end of the file" is actually
a reasonably common case.

It may not make for a great filesystem benchmark, but it also isn't
actually insane. People who do logging in user space do this all the
time, for example. And it is *not* stupid in that context. Not at all.

It's never going to be the *main* thing you do (unless you're AIM),
but I do think it's worth fixing.

And AIM7 remains one of those odd benchmarks that people use. I'm not
quite sure why, but I really do think that the normal "append smaller
chunks to the end of the file" should absolutely not be dismissed as
stupid.

                Linus

  reply	other threads:[~2016-08-12  3:20 UTC|newest]

Thread overview: 219+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-09 14:33 [lkp] [xfs] 68a9f5e700: aim7.jobs-per-min -13.6% regression kernel test robot
2016-08-09 14:33 ` kernel test robot
2016-08-10 18:24 ` [lkp] " Linus Torvalds
2016-08-10 18:24   ` Linus Torvalds
2016-08-10 23:08   ` [lkp] " Dave Chinner
2016-08-10 23:08     ` Dave Chinner
2016-08-10 23:51     ` [lkp] " Linus Torvalds
2016-08-10 23:51       ` Linus Torvalds
2016-08-10 23:58       ` [LKP] [lkp] " Huang, Ying
2016-08-10 23:58         ` Huang, Ying
2016-08-11  0:11         ` [LKP] [lkp] " Huang, Ying
2016-08-11  0:11           ` Huang, Ying
2016-08-11  0:23           ` [LKP] [lkp] " Linus Torvalds
2016-08-11  0:23             ` Linus Torvalds
2016-08-11  0:33             ` [LKP] [lkp] " Huang, Ying
2016-08-11  0:33               ` Huang, Ying
2016-08-11  1:00               ` [LKP] [lkp] " Linus Torvalds
2016-08-11  1:00                 ` Linus Torvalds
2016-08-11  4:46                 ` [LKP] [lkp] " Dave Chinner
2016-08-11  4:46                   ` Dave Chinner
2016-08-15 17:22                   ` [LKP] [lkp] " Huang, Ying
2016-08-15 17:22                     ` Huang, Ying
2016-08-16  0:08                     ` [LKP] [lkp] " Dave Chinner
2016-08-16  0:08                       ` Dave Chinner
2016-08-11 15:57                 ` [LKP] [lkp] " Christoph Hellwig
2016-08-11 15:57                   ` Christoph Hellwig
2016-08-11 16:55                   ` [LKP] [lkp] " Linus Torvalds
2016-08-11 16:55                     ` Linus Torvalds
2016-08-11 17:51                     ` [LKP] [lkp] " Huang, Ying
2016-08-11 17:51                       ` Huang, Ying
2016-08-11 19:51                       ` [LKP] [lkp] " Linus Torvalds
2016-08-11 19:51                         ` Linus Torvalds
2016-08-11 20:00                         ` [LKP] [lkp] " Christoph Hellwig
2016-08-11 20:00                           ` Christoph Hellwig
2016-08-11 20:35                           ` [LKP] [lkp] " Linus Torvalds
2016-08-11 20:35                             ` Linus Torvalds
2016-08-11 22:16                             ` [LKP] [lkp] " Al Viro
2016-08-11 22:16                               ` Al Viro
2016-08-11 22:30                               ` [LKP] [lkp] " Linus Torvalds
2016-08-11 22:30                                 ` Linus Torvalds
2016-08-11 21:16                           ` [LKP] [lkp] " Huang, Ying
2016-08-11 21:16                             ` Huang, Ying
2016-08-11 21:40                             ` [LKP] [lkp] " Linus Torvalds
2016-08-11 21:40                               ` Linus Torvalds
2016-08-11 22:08                               ` [LKP] [lkp] " Christoph Hellwig
2016-08-11 22:08                                 ` Christoph Hellwig
2016-08-12  0:54                     ` [LKP] [lkp] " Dave Chinner
2016-08-12  0:54                       ` Dave Chinner
2016-08-12  2:23                       ` [LKP] [lkp] " Dave Chinner
2016-08-12  2:23                         ` Dave Chinner
2016-08-12  2:32                         ` [LKP] [lkp] " Linus Torvalds
2016-08-12  2:32                           ` Linus Torvalds
2016-08-12  2:52                         ` [LKP] [lkp] " Christoph Hellwig
2016-08-12  2:52                           ` Christoph Hellwig
2016-08-12  3:20                           ` Linus Torvalds [this message]
2016-08-12  3:20                             ` Linus Torvalds
2016-08-12  4:16                             ` [LKP] [lkp] " Dave Chinner
2016-08-12  4:16                               ` Dave Chinner
2016-08-12  5:02                               ` [LKP] [lkp] " Linus Torvalds
2016-08-12  5:02                                 ` Linus Torvalds
2016-08-12  6:04                                 ` [LKP] [lkp] " Dave Chinner
2016-08-12  6:04                                   ` Dave Chinner
2016-08-12  6:29                                   ` [LKP] [lkp] " Ye Xiaolong
2016-08-12  6:29                                     ` Ye Xiaolong
2016-08-12  8:51                                     ` [LKP] [lkp] " Ye Xiaolong
2016-08-12  8:51                                       ` Ye Xiaolong
2016-08-12 10:02                                       ` [LKP] [lkp] " Dave Chinner
2016-08-12 10:02                                         ` Dave Chinner
2016-08-12 10:43                                         ` Fengguang Wu
2016-08-12 10:43                                           ` Fengguang Wu
2016-08-13  0:30                                         ` [LKP] [lkp] " Christoph Hellwig
2016-08-13  0:30                                           ` Christoph Hellwig
2016-08-13 21:48                                           ` [LKP] [lkp] " Christoph Hellwig
2016-08-13 21:48                                             ` Christoph Hellwig
2016-08-13 22:07                                             ` [LKP] [lkp] " Fengguang Wu
2016-08-13 22:07                                               ` Fengguang Wu
2016-08-13 22:15                                               ` [LKP] [lkp] " Christoph Hellwig
2016-08-13 22:15                                                 ` Christoph Hellwig
2016-08-13 22:51                                                 ` [LKP] [lkp] " Fengguang Wu
2016-08-13 22:51                                                   ` Fengguang Wu
2016-08-14 14:50                                                   ` [LKP] [lkp] " Fengguang Wu
2016-08-14 14:50                                                     ` Fengguang Wu
2016-08-14 16:17                                                     ` [LKP] [lkp] " Christoph Hellwig
2016-08-14 16:17                                                       ` Christoph Hellwig
2016-08-14 23:46                                                       ` [LKP] [lkp] " Dave Chinner
2016-08-14 23:46                                                         ` Dave Chinner
2016-08-14 23:57                                                       ` [LKP] [lkp] " Fengguang Wu
2016-08-14 23:57                                                         ` Fengguang Wu
2016-08-15 14:14                                                       ` [LKP] [lkp] " Fengguang Wu
2016-08-15 14:14                                                         ` Fengguang Wu
2016-08-15 21:22                                                         ` [LKP] [lkp] " Dave Chinner
2016-08-15 21:22                                                           ` Dave Chinner
2016-08-16 12:20                                                           ` [LKP] [lkp] " Fengguang Wu
2016-08-16 12:20                                                             ` Fengguang Wu
2016-08-15 20:30                                                       ` [LKP] [lkp] " Huang, Ying
2016-08-15 20:30                                                         ` Huang, Ying
2016-08-22 22:09                                                         ` [LKP] [lkp] " Huang, Ying
2016-08-22 22:09                                                           ` Huang, Ying
2016-09-26  6:25                                                           ` [LKP] [lkp] " Huang, Ying
2016-09-26  6:25                                                             ` Huang, Ying
2016-09-26 14:55                                                             ` [LKP] [lkp] " Christoph Hellwig
2016-09-26 14:55                                                               ` Christoph Hellwig
2016-09-27  0:52                                                               ` [LKP] [lkp] " Huang, Ying
2016-09-27  0:52                                                                 ` Huang, Ying
2016-08-16 13:25                                                       ` [LKP] [lkp] " Fengguang Wu
2016-08-16 13:25                                                         ` Fengguang Wu
2016-08-13 23:32                                           ` [LKP] [lkp] " Dave Chinner
2016-08-13 23:32                                             ` Dave Chinner
2016-08-12  2:27                       ` [LKP] [lkp] " Linus Torvalds
2016-08-12  2:27                         ` Linus Torvalds
2016-08-12  3:56                         ` [LKP] [lkp] " Dave Chinner
2016-08-12  3:56                           ` Dave Chinner
2016-08-12 18:03                           ` [LKP] [lkp] " Linus Torvalds
2016-08-12 18:03                             ` Linus Torvalds
2016-08-13 23:58                             ` [LKP] [lkp] " Fengguang Wu
2016-08-13 23:58                               ` Fengguang Wu
2016-08-15  0:48                             ` [LKP] [lkp] " Dave Chinner
2016-08-15  0:48                               ` Dave Chinner
2016-08-15  1:37                               ` [LKP] [lkp] " Linus Torvalds
2016-08-15  1:37                                 ` Linus Torvalds
2016-08-15  2:28                                 ` [LKP] [lkp] " Dave Chinner
2016-08-15  2:28                                   ` Dave Chinner
2016-08-15  2:53                                   ` [LKP] [lkp] " Linus Torvalds
2016-08-15  2:53                                     ` Linus Torvalds
2016-08-15  5:00                                     ` [LKP] [lkp] " Dave Chinner
2016-08-15  5:00                                       ` Dave Chinner
     [not found]                                       ` <CA+55aFwva2Xffai+Eqv1Jn_NGryk3YJ2i5JoHOQnbQv6qVPAsw@mail.gmail.com>
     [not found]                                         ` <CA+55aFy14nUnJQ_GdF=j8Fa9xiH70c6fY2G3q5HQ01+8z1z3qQ@mail.gmail.com>
2016-08-15  5:12                                           ` Linus Torvalds
2016-08-15 22:22                                             ` [LKP] [lkp] " Dave Chinner
2016-08-15 22:22                                               ` Dave Chinner
2016-08-15 22:42                                               ` [LKP] [lkp] " Dave Chinner
2016-08-15 22:42                                                 ` Dave Chinner
2016-08-15 23:20                                                 ` [LKP] [lkp] " Linus Torvalds
2016-08-15 23:20                                                   ` Linus Torvalds
2016-08-15 23:48                                                   ` [LKP] [lkp] " Linus Torvalds
2016-08-15 23:48                                                     ` Linus Torvalds
2016-08-16  0:44                                                     ` [LKP] [lkp] " Dave Chinner
2016-08-16  0:44                                                       ` Dave Chinner
2016-08-16 15:05                                                     ` [LKP] [lkp] " Mel Gorman
2016-08-16 15:05                                                       ` Mel Gorman
2016-08-16 17:47                                                       ` [LKP] [lkp] " Linus Torvalds
2016-08-16 17:47                                                         ` Linus Torvalds
2016-08-17 15:48                                                         ` [LKP] [lkp] " Michal Hocko
2016-08-17 15:48                                                           ` Michal Hocko
2016-08-17 16:42                                                           ` [LKP] [lkp] " Michal Hocko
2016-08-17 16:42                                                             ` Michal Hocko
2016-08-17 15:49                                                         ` [LKP] [lkp] " Mel Gorman
2016-08-17 15:49                                                           ` Mel Gorman
2016-08-18  0:45                                                           ` [LKP] [lkp] " Mel Gorman
2016-08-18  0:45                                                             ` Mel Gorman
2016-08-18  7:11                                                             ` [LKP] [lkp] " Dave Chinner
2016-08-18  7:11                                                               ` Dave Chinner
2016-08-18 13:24                                                               ` [LKP] [lkp] " Mel Gorman
2016-08-18 13:24                                                                 ` Mel Gorman
2016-08-18 17:55                                                                 ` [LKP] [lkp] " Linus Torvalds
2016-08-18 17:55                                                                   ` Linus Torvalds
2016-08-18 21:19                                                                   ` [LKP] [lkp] " Dave Chinner
2016-08-18 21:19                                                                     ` Dave Chinner
2016-08-18 22:25                                                                     ` [LKP] [lkp] " Linus Torvalds
2016-08-18 22:25                                                                       ` Linus Torvalds
2016-08-19  9:00                                                                       ` [LKP] [lkp] " Michal Hocko
2016-08-19  9:00                                                                         ` Michal Hocko
2016-08-19 10:49                                                                       ` [LKP] [lkp] " Mel Gorman
2016-08-19 10:49                                                                         ` Mel Gorman
2016-08-19 23:48                                                                         ` [LKP] [lkp] " Dave Chinner
2016-08-19 23:48                                                                           ` Dave Chinner
2016-08-20  1:08                                                                           ` [LKP] [lkp] " Linus Torvalds
2016-08-20  1:08                                                                             ` Linus Torvalds
2016-08-20 12:16                                                                           ` [LKP] [lkp] " Mel Gorman
2016-08-20 12:16                                                                             ` Mel Gorman
2016-08-19 15:08                                                               ` [LKP] [lkp] " Mel Gorman
2016-08-19 15:08                                                                 ` Mel Gorman
2016-09-01 23:32                                                                 ` [LKP] [lkp] " Dave Chinner
2016-09-01 23:32                                                                   ` Dave Chinner
2016-09-06 15:37                                                                   ` [LKP] [lkp] " Mel Gorman
2016-09-06 15:37                                                                     ` Mel Gorman
2016-09-06 15:52                                                                     ` [LKP] [lkp] " Huang, Ying
2016-09-06 15:52                                                                       ` Huang, Ying
2016-08-24 15:40                                                             ` [LKP] [lkp] " Huang, Ying
2016-08-24 15:40                                                               ` Huang, Ying
2016-08-25  9:37                                                               ` [LKP] [lkp] " Mel Gorman
2016-08-25  9:37                                                                 ` Mel Gorman
2016-08-18  2:44                                                           ` [LKP] [lkp] " Dave Chinner
2016-08-18  2:44                                                             ` Dave Chinner
2016-08-16  0:15                                                   ` [LKP] [lkp] " Linus Torvalds
2016-08-16  0:15                                                     ` Linus Torvalds
2016-08-16  0:38                                                     ` [LKP] [lkp] " Dave Chinner
2016-08-16  0:38                                                       ` Dave Chinner
2016-08-16  0:50                                                       ` [LKP] [lkp] " Linus Torvalds
2016-08-16  0:50                                                         ` Linus Torvalds
2016-08-16  0:19                                                   ` [LKP] [lkp] " Dave Chinner
2016-08-16  0:19                                                     ` Dave Chinner
2016-08-16  1:51                                                     ` [LKP] [lkp] " Linus Torvalds
2016-08-16  1:51                                                       ` Linus Torvalds
2016-08-16 22:02                                                       ` [LKP] [lkp] " Dave Chinner
2016-08-16 22:02                                                         ` Dave Chinner
2016-08-16 23:23                                                         ` [LKP] [lkp] " Linus Torvalds
2016-08-16 23:23                                                           ` Linus Torvalds
2016-08-15 23:01                                               ` [LKP] [lkp] " Linus Torvalds
2016-08-15 23:01                                                 ` Linus Torvalds
2016-08-16  0:17                                                 ` [LKP] [lkp] " Dave Chinner
2016-08-16  0:17                                                   ` Dave Chinner
2016-08-16  0:45                                                   ` [LKP] [lkp] " Linus Torvalds
2016-08-16  0:45                                                     ` Linus Torvalds
2016-08-15  5:03                                     ` [LKP] [lkp] " Ingo Molnar
2016-08-15  5:03                                       ` Ingo Molnar
2016-08-17 16:24                                       ` [LKP] [lkp] " Peter Zijlstra
2016-08-17 16:24                                         ` Peter Zijlstra
2016-08-15 12:58                             ` [LKP] [lkp] " Fengguang Wu
2016-08-15 12:58                               ` Fengguang Wu
2016-08-11  1:16               ` [LKP] [lkp] " Dave Chinner
2016-08-11  1:16                 ` Dave Chinner
2016-08-11  1:32                 ` [LKP] [lkp] " Dave Chinner
2016-08-11  1:32                   ` Dave Chinner
2016-08-11  2:36                   ` [LKP] [lkp] " Ye Xiaolong
2016-08-11  2:36                     ` Ye Xiaolong
2016-08-11  3:05                     ` [LKP] [lkp] " Dave Chinner
2016-08-11  3:05                       ` Dave Chinner
2016-08-12  1:26                 ` [LKP] [lkp] " Dave Chinner
2016-08-12  1:26                   ` Dave Chinner

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