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From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <longman@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>, Will Deacon <will.deacon@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	Davidlohr Bueso <dave@stgolabs.net>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	huang ying <huang.ying.caritas@gmail.com>
Subject: Re: [PATCH-tip 0/2] locking/rwsem: Rwsem rearchitecture part 2 follow-up patches
Date: Tue, 16 Apr 2019 19:37:00 +0200	[thread overview]
Message-ID: <20190416173700.GQ4038@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <18af71ce-1ef3-c6cd-4088-3b2a9bf0016e@redhat.com>

On Tue, Apr 16, 2019 at 01:03:10PM -0400, Waiman Long wrote:
> On 04/16/2019 10:17 AM, Peter Zijlstra wrote:
> > On Tue, Apr 16, 2019 at 09:18:50AM -0400, Waiman Long wrote:
> >> On 04/16/2019 09:10 AM, Peter Zijlstra wrote:
> >>> On Mon, Apr 15, 2019 at 04:58:27PM -0400, Waiman Long wrote:
> >>>> This series contain 2 follow-up patches to alleviate the performance
> >>>> regression found in the page_fault1 test of the will-it-scale benchmark.
> >>>> This does not recover all the lost performance, but reclaim a sizeable
> >>>> portion of it.
> >>>>
> >>>> The regression was found on an Intel system. I have run the test on
> >>>> an AMD system. The regression wasn't seen there.  There are only minor
> >>>> variations in performance. Perhaps the page fault path is quite different
> >>>> between Intel and AMD systems.
> >>> Can you please just fold this back into the appropriate patches? Trying
> >>> to review all the back and forth is painful.
> >> I will send out an update part 2 patch with patch 1 of this series
> >> merged into the writer spinning on reader patch. Patch 2 of this series
> >> will be a standalone one.
> > Hmm, in that case I can fold it back too. So hold off on sending it.
> >
> > I thought #2 was a fixup for an earlier patch as well.
> 
> #2 is a performance fix.

Of this patch?

206038 N T Apr 13 Waiman Long     (7.5K) ├─>[PATCH v4 11/16] locking/rwsem: Enable readers spinning on writer

Fixes should have a Fixes: tag. And if the patch it fixes isn't a commit
yet, the patch should be refreshed to not need a fix.

  reply	other threads:[~2019-04-16 17:37 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-15 20:58 [PATCH-tip 0/2] locking/rwsem: Rwsem rearchitecture part 2 follow-up patches Waiman Long
2019-04-15 20:58 ` [PATCH-tip 1/2] locking/rwsem: Clarify usage of owner's nonspinaable bit Waiman Long
2019-04-15 20:58 ` [PATCH-tip 2/2] locking/rwsem: Adaptive disabling of reader optimistic spinning Waiman Long
2019-04-16 13:10 ` [PATCH-tip 0/2] locking/rwsem: Rwsem rearchitecture part 2 follow-up patches Peter Zijlstra
2019-04-16 13:18   ` Waiman Long
2019-04-16 14:17     ` Peter Zijlstra
2019-04-16 17:03       ` Waiman Long
2019-04-16 17:37         ` Peter Zijlstra [this message]
2019-04-16 19:49           ` Waiman Long
2019-04-17  5:57             ` Ingo Molnar
2019-04-17 20:30               ` Waiman Long
2019-04-18  8:02                 ` Ingo Molnar
2019-04-18 12:42                   ` Waiman Long

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