From: Dave Chinner <david@fromorbit.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Bob Peterson <rpeterso@redhat.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
"Huang, Ying" <ying.huang@intel.com>,
Christoph Hellwig <hch@lst.de>,
Wu Fengguang <fengguang.wu@intel.com>, LKP <lkp@01.org>,
Tejun Heo <tj@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [LKP] [lkp] [xfs] 68a9f5e700: aim7.jobs-per-min -13.6% regression
Date: Tue, 16 Aug 2016 10:17:21 +1000 [thread overview]
Message-ID: <20160816001721.GC19025@dastard> (raw)
In-Reply-To: <CA+55aFyy1Q95mk48rnoDAPs00s5OL+OOuqJBBwRy-M43H=jDYw@mail.gmail.com>
On Mon, Aug 15, 2016 at 04:01:00PM -0700, Linus Torvalds wrote:
> On Mon, Aug 15, 2016 at 3:22 PM, Dave Chinner <david@fromorbit.com> wrote:
> >
> > Right, but that does not make the profile data useless,
>
> Yes it does. Because it basically hides everything that happens inside
> the lock, which is what causes the contention in the first place.
Read the code, Linus?
> So stop making inane and stupid arguments, Dave.
We know what happens inside the lock, and we know exactly how much
it is supposed to cost. And it isn't anywhere near as much as the
profiles indicate the function that contains the lock is costing.
Occam's Razor leads to only one conclusion, like it or not....
> Your profiles are shit. Deal with it, or accept that nobody is ever
> going to bother working on them because your profiles don't give
> useful information.
>
> I see that you actually fixed your profiles, but quite frankly, the
> amount of pure unadulterated crap you posted in this email is worth
> reacting negatively to.
I'm happy to be told that I'm wrong *when I'm wrong*, but you always
say "read the code to understand a problem" rather than depending on
potentially unreliable tools and debug information that is gathered.
Yet when I do that using partial profile information, your reaction
is to tell me I am "full of shit" because my information isn't 100%
reliable? Really, Linus?
> You generally make so much sense that it's shocking to see you then
> make these crazy excuses for your completely broken profiles.
Except they *aren't broken*. They are simply *less accurate* than
they could be. That does not invalidate the profile nor does it mean
that the insight it gives us into the functioning of the code is
wrong.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2016-08-16 0:32 UTC|newest]
Thread overview: 109+ 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
2016-08-10 18:24 ` Linus Torvalds
2016-08-10 23:08 ` Dave Chinner
2016-08-10 23:51 ` Linus Torvalds
2016-08-10 23:58 ` [LKP] " Huang, Ying
2016-08-11 0:11 ` Huang, Ying
2016-08-11 0:23 ` Linus Torvalds
2016-08-11 0:33 ` Huang, Ying
2016-08-11 1:00 ` Linus Torvalds
2016-08-11 4:46 ` Dave Chinner
2016-08-15 17:22 ` Huang, Ying
2016-08-16 0:08 ` Dave Chinner
2016-08-11 15:57 ` Christoph Hellwig
2016-08-11 16:55 ` Linus Torvalds
2016-08-11 17:51 ` Huang, Ying
2016-08-11 19:51 ` Linus Torvalds
2016-08-11 20:00 ` Christoph Hellwig
2016-08-11 20:35 ` Linus Torvalds
2016-08-11 22:16 ` Al Viro
2016-08-11 22:30 ` Linus Torvalds
2016-08-11 21:16 ` Huang, Ying
2016-08-11 21:40 ` Linus Torvalds
2016-08-11 22:08 ` Christoph Hellwig
2016-08-12 0:54 ` Dave Chinner
2016-08-12 2:23 ` Dave Chinner
2016-08-12 2:32 ` Linus Torvalds
2016-08-12 2:52 ` Christoph Hellwig
2016-08-12 3:20 ` Linus Torvalds
2016-08-12 4:16 ` Dave Chinner
2016-08-12 5:02 ` Linus Torvalds
2016-08-12 6:04 ` Dave Chinner
2016-08-12 6:29 ` Ye Xiaolong
2016-08-12 8:51 ` Ye Xiaolong
2016-08-12 10:02 ` Dave Chinner
2016-08-12 10:43 ` Fengguang Wu
2016-08-13 0:30 ` [LKP] [lkp] " Christoph Hellwig
2016-08-13 21:48 ` Christoph Hellwig
2016-08-13 22:07 ` Fengguang Wu
2016-08-13 22:15 ` Christoph Hellwig
2016-08-13 22:51 ` Fengguang Wu
2016-08-14 14:50 ` Fengguang Wu
2016-08-14 16:17 ` Christoph Hellwig
2016-08-14 23:46 ` Dave Chinner
2016-08-14 23:57 ` Fengguang Wu
2016-08-15 14:14 ` Fengguang Wu
2016-08-15 21:22 ` Dave Chinner
2016-08-16 12:20 ` Fengguang Wu
2016-08-15 20:30 ` Huang, Ying
2016-08-22 22:09 ` Huang, Ying
2016-09-26 6:25 ` Huang, Ying
2016-09-26 14:55 ` Christoph Hellwig
2016-09-27 0:52 ` Huang, Ying
2016-08-16 13:25 ` Fengguang Wu
2016-08-13 23:32 ` Dave Chinner
2016-08-12 2:27 ` Linus Torvalds
2016-08-12 3:56 ` Dave Chinner
2016-08-12 18:03 ` Linus Torvalds
2016-08-13 23:58 ` Fengguang Wu
2016-08-15 0:48 ` Dave Chinner
2016-08-15 1:37 ` Linus Torvalds
2016-08-15 2:28 ` Dave Chinner
2016-08-15 2:53 ` Linus Torvalds
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>
[not found] ` <CA+55aFxp+rLehC8c157uRbH459wUC1rRPfCVgvmcq5BrG9gkyg@mail.gmail.com>
2016-08-15 22:22 ` Dave Chinner
2016-08-15 22:42 ` Dave Chinner
2016-08-15 23:20 ` Linus Torvalds
2016-08-15 23:48 ` Linus Torvalds
2016-08-16 0:44 ` Dave Chinner
2016-08-16 15:05 ` Mel Gorman
2016-08-16 17:47 ` Linus Torvalds
2016-08-17 15:48 ` Michal Hocko
2016-08-17 16:42 ` Michal Hocko
2016-08-17 15:49 ` Mel Gorman
2016-08-18 0:45 ` Mel Gorman
2016-08-18 7:11 ` Dave Chinner
2016-08-18 13:24 ` Mel Gorman
2016-08-18 17:55 ` Linus Torvalds
2016-08-18 21:19 ` Dave Chinner
2016-08-18 22:25 ` Linus Torvalds
2016-08-19 9:00 ` Michal Hocko
2016-08-19 10:49 ` Mel Gorman
2016-08-19 23:48 ` Dave Chinner
2016-08-20 1:08 ` Linus Torvalds
2016-08-20 12:16 ` Mel Gorman
2016-08-19 15:08 ` Mel Gorman
2016-09-01 23:32 ` Dave Chinner
2016-09-06 15:37 ` Mel Gorman
2016-09-06 15:52 ` Huang, Ying
2016-08-24 15:40 ` Huang, Ying
2016-08-25 9:37 ` Mel Gorman
2016-08-18 2:44 ` Dave Chinner
2016-08-16 0:15 ` Linus Torvalds
2016-08-16 0:38 ` Dave Chinner
2016-08-16 0:50 ` Linus Torvalds
2016-08-16 0:19 ` Dave Chinner
2016-08-16 1:51 ` Linus Torvalds
2016-08-16 22:02 ` Dave Chinner
2016-08-16 23:23 ` Linus Torvalds
2016-08-15 23:01 ` Linus Torvalds
2016-08-16 0:17 ` Dave Chinner [this message]
2016-08-16 0:45 ` Linus Torvalds
2016-08-15 5:03 ` Ingo Molnar
2016-08-17 16:24 ` Peter Zijlstra
2016-08-15 12:58 ` Fengguang Wu
2016-08-11 1:16 ` Dave Chinner
2016-08-11 1:32 ` Dave Chinner
2016-08-11 2:36 ` Ye Xiaolong
2016-08-11 3:05 ` Dave Chinner
2016-08-12 1:26 ` Dave Chinner
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