From: Christoph Hellwig <hch@lst.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Peter Zijlstra" <peterz@infradead.org>,
"Christoph Hellwig" <hch@lst.de>,
"Ingo Molnar" <mingo@kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Will Deacon" <will@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
"Jens Axboe" <axboe@kernel.dk>,
"Chris Wilson" <chris@chris-wilson.co.uk>,
"David Miller" <davem@davemloft.net>,
"Jakub Kicinski" <kuba@kernel.org>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
"Oleg Nesterov" <oleg@redhat.com>,
"Vincent Guittot" <vincent.guittot@linaro.org>
Subject: Re: [RFC][PATCH v2 08/10] smp,irq_work: Use the new irq_work API
Date: Thu, 20 Aug 2020 08:20:24 +0200 [thread overview]
Message-ID: <20200820062024.GB6447@lst.de> (raw)
In-Reply-To: <CAHk-=wgMATDQQxLSsgmxCoCqApVXVeRnGOf6iWjnYdTJY_R3aw@mail.gmail.com>
On Wed, Aug 19, 2020 at 11:50:55AM -0700, Linus Torvalds wrote:
> On Wed, Aug 19, 2020 at 12:22 AM <peterz@infradead.org> wrote:
> >
> > That is, the external serialization comes from the non-atomic
> > test-and-set they both have. This works nicely when there is external
> > state that already serializes things, but totally comes apart (and
> > causes trivial list corruption) when you get it wrong.
>
> Quite often, there just isn't any *need* for serialization, because
> there is only ever one op active.
Yes, that's pretty much the block use case. The request gets completed
once, and and the IPI is used to bounce it back to the issuing cpu.
next prev parent reply other threads:[~2020-08-20 6:20 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-18 10:51 [PATCH v2 00/10] smp: irq_work / smp_call_function rework Peter Zijlstra
2020-08-18 10:51 ` [PATCH v2 01/10] irq_work: Cleanup Peter Zijlstra
2020-08-18 10:51 ` [PATCH v2 02/10] smp: Cleanup smp_call_function*() Peter Zijlstra
2020-08-18 10:51 ` [PATCH v2 03/10] irq_work: Optimize irq_work_single() Peter Zijlstra
2020-08-18 10:51 ` [PATCH v2 04/10] irq_work: Unconditionally build on SMP Peter Zijlstra
2020-08-18 10:51 ` [PATCH v2 05/10] irq_work: Provide irq_work_queue_remote() Peter Zijlstra
2020-08-18 10:51 ` [RFC][PATCH v2 06/10] irq_work: Provide irq_work_queue_remote_static() Peter Zijlstra
2020-08-18 10:51 ` [RFC][PATCH v2 07/10] sched/fair: Exclude the current CPU from find_new_ilb() Peter Zijlstra
2020-08-18 10:51 ` [RFC][PATCH v2 08/10] smp,irq_work: Use the new irq_work API Peter Zijlstra
2020-08-18 16:25 ` Christoph Hellwig
2020-08-19 7:22 ` peterz
2020-08-19 18:50 ` Linus Torvalds
2020-08-19 19:41 ` peterz
2020-08-19 22:04 ` Linus Torvalds
2020-08-20 13:08 ` peterz
2020-08-20 6:20 ` Christoph Hellwig [this message]
2020-08-20 6:19 ` Christoph Hellwig
2020-08-20 13:40 ` peterz
2020-09-09 8:03 ` Christoph Hellwig
2020-08-18 10:51 ` [RFC][PATCH v2 09/10] smp: Make smp_call_function_single_async() safer Peter Zijlstra
2020-08-18 10:51 ` [RFC][PATCH v2 10/10] irq_work: Add a few comments Peter Zijlstra
2020-08-18 15:52 ` Randy Dunlap
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