From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Bongkyu Kim <bongkyu7.kim@samsung.com>,
mingo@redhat.com, will@kernel.org, longman@redhat.com,
boqun.feng@gmail.com, linux-kernel@vger.kernel.org,
gregkh@linuxfoundation.org
Subject: Re: [PATCH v2 1/2] Revert "locking/rwsem: Remove reader optimistic spinning"
Date: Mon, 4 Sep 2023 21:11:31 +0200 [thread overview]
Message-ID: <ZPYr4z/h2lZLtqoZ@gmail.com> (raw)
In-Reply-To: <20230904151008.GA25717@noisy.programming.kicks-ass.net>
* Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Sep 01, 2023 at 10:07:03AM +0900, Bongkyu Kim wrote:
> > This reverts commit 617f3ef95177840c77f59c2aec1029d27d5547d6.
> >
> > In mobile environment, reader optimistic spinning is still useful
> > because there're not many readers. In my test result at android device,
> > it improves application startup time about 3.8%
> > App startup time is most important factor for android user expriences.
> > So, re-enable reader optimistic spinning by this commit. And,
> > the later patch will make it optional feature by cmdline.
>
> I'm not seeing any mention on how this interacts with all the rwsem work
> that has been done since that commit, like the handoff rework.
>
> Why is a straight revert a sane thing at this point?
Yeah, so this should probably be titled:
locking/rwsem: Reintroduce reader optimistic spinning
... instead of the double-negative 'remove removal' thing that is indeed
confusing.
Thanks,
Ingo
next prev parent reply other threads:[~2023-09-04 19:11 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20230901010734epcas2p4aadced02d68d3db407fda23de34601d2@epcas2p4.samsung.com>
2023-09-01 1:07 ` [PATCH v2 0/2] Make reader optimistic spinning optional Bongkyu Kim
2023-09-01 1:07 ` [PATCH v2 1/2] Revert "locking/rwsem: Remove reader optimistic spinning" Bongkyu Kim
2023-09-04 15:10 ` Peter Zijlstra
2023-09-04 19:11 ` Ingo Molnar [this message]
2023-09-04 19:56 ` Waiman Long
2023-09-06 11:27 ` Bongkyu Kim
2023-09-06 13:32 ` Waiman Long
2023-09-20 4:09 ` Bongkyu Kim
2023-09-01 1:07 ` [PATCH v2 2/2] locking/rwsem: Make reader optimistic spinning optional Bongkyu Kim
2023-09-04 15:10 ` Peter Zijlstra
2024-04-02 23:46 ` [PATCH v2 0/2] " John Stultz
2024-04-03 1:21 ` Bongkyu Kim
2024-04-03 1:27 ` John Stultz
2024-04-03 1:42 ` Bongkyu Kim
2024-04-04 17:44 ` Waiman Long
2024-04-05 3:06 ` Waiman Long
2024-04-05 6:37 ` Bongkyu Kim
2024-04-05 6:51 ` Bongkyu Kim
2024-04-08 8:15 ` xieliujie
2024-04-09 0:50 ` Bongkyu Kim
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