From: Andrew Morton <akpm@linux-foundation.org>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Davidlohr Bueso <dave@stgolabs.net>,
LKML <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
1vier1@web.de, felixh@informatik.uni-bremen.de
Subject: Re: [PATCH 0/2] ipc/sem.c: sem_lock fixes
Date: Wed, 13 Jul 2016 15:05:25 -0700 [thread overview]
Message-ID: <20160713150525.8f703dfa5e83a534f8a51106@linux-foundation.org> (raw)
In-Reply-To: <1468386412-3608-1-git-send-email-manfred@colorfullife.com>
On Wed, 13 Jul 2016 07:06:50 +0200 Manfred Spraul <manfred@colorfullife.com> wrote:
> Hi Andrew, Hi Peter,
>
> next version of the sem_lock() fixes:
> The patches are again vs. tip.
>
> Patch 1 is ready for merging, Patch 2 is for review.
>
> - Patch 1 is the patch as in -next since January
> It fixes the race that was found by Felix.
> - Patch 2 removes the memory barriers that are part of the qspinlock
> code.
> - (The hysteresis patch would be patch 3. The risk of regressions
> can't be ruled out, thus it must wait for benchmarks from real
> workload tests)
I think you're saying that if these two patches cause performance
regressions, we will need ipc-sem-sem_lock-with-hysteresis.patch?
Is that even necessary? If your testing shows that
ipc-sem-sem_lock-with-hysteresis.patch makes things faster then in it
goes, surely?
next prev parent reply other threads:[~2016-07-13 22:05 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-13 5:06 Manfred Spraul
2016-07-13 5:06 ` [PATCH 1/2] ipc/sem.c: Fix complex_count vs. simple op race Manfred Spraul
2016-07-13 5:06 ` [PATCH 2/2] ipc/sem.c: Remove duplicated memory barriers Manfred Spraul
2016-07-13 16:16 ` Davidlohr Bueso
2016-07-13 18:37 ` Manfred Spraul
2016-07-16 1:27 ` [PATCH 1/2] ipc/sem.c: Fix complex_count vs. simple op race Davidlohr Bueso
2016-07-13 22:05 ` Andrew Morton [this message]
2016-07-14 16:40 ` [PATCH 0/2] ipc/sem.c: sem_lock fixes Manfred Spraul
-- strict thread matches above, loose matches on Subject: below --
2016-10-01 18:40 Manfred Spraul
2016-06-25 17:37 Manfred Spraul
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