From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
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 15:49:07 -0400 [thread overview]
Message-ID: <2873c42c-f2a6-64e9-bf0f-9c86536984b7@redhat.com> (raw)
In-Reply-To: <20190416173700.GQ4038@hirez.programming.kicks-ass.net>
On 04/16/2019 01:37 PM, Peter Zijlstra wrote:
> 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.
The original patch isn't wrong. This patch just introduce another idea
to make it better. That is why I would still like to separate it as a
distinct patch.
Cheers,
Longman
next prev parent reply other threads:[~2019-04-16 19:49 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
2019-04-16 19:49 ` Waiman Long [this message]
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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