From: Ingo Molnar <mingo@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael David Tinoco <inaddy@ubuntu.com>,
Peter Anvin <hpa@zytor.com>,
Jiang Liu <jiang.liu@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>, Jens Axboe <axboe@kernel.dk>,
Frederic Weisbecker <fweisbec@gmail.com>,
Gema Gomez <gema.gomez-solano@canonical.com>,
Christopher Arges <chris.j.arges@canonical.com>,
the arch/x86 maintainers <x86@kernel.org>
Subject: Re: smp_call_function_single lockups
Date: Fri, 20 Feb 2015 21:11:23 +0100 [thread overview]
Message-ID: <20150220201123.GD3603@gmail.com> (raw)
In-Reply-To: <CA+55aFxcVNyogK6wc8B6ZjSZk1czwF9XRPc69C_Y52+hUQYSCA@mail.gmail.com>
* Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Fri, Feb 20, 2015 at 11:41 AM, Ingo Molnar <mingo@kernel.org> wrote:
> >
> > I'm not so sure about that aspect: I think disabling
> > IRQs might be necessary with some APICs (if lower
> > levels don't disable IRQs), to make sure the 'local
> > APIC busy' bit isn't set:
>
> Right. But afaik not for the x2apic case, which this is.
> The x2apic doesn't even have a busy bit, and sending the
> ipi is a single write,
Ah, ok! Then the patch looks good to me.
( Originally we didn't wait for the ICR bit either, but
then it was added due to later erratas and was eventually
made an architectural requirement. )
> I agree that when doing other apic implementations, we
> may need to guarantee atomicity for things like "wait for
> apic idle, then send the ipi".
Yeah.
Thanks,
Ingo
next prev parent reply other threads:[~2015-02-20 20:11 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-11 13:19 smp_call_function_single lockups Rafael David Tinoco
2015-02-11 18:18 ` Linus Torvalds
2015-02-11 19:59 ` Linus Torvalds
2015-02-11 20:42 ` Linus Torvalds
2015-02-12 16:38 ` Rafael David Tinoco
2015-02-18 22:25 ` Peter Zijlstra
2015-02-19 15:42 ` Rafael David Tinoco
2015-02-19 16:14 ` Linus Torvalds
2015-02-23 14:01 ` Rafael David Tinoco
2015-02-23 19:32 ` Linus Torvalds
2015-02-23 20:50 ` Peter Zijlstra
2015-02-23 21:02 ` Rafael David Tinoco
2015-02-19 16:16 ` Peter Zijlstra
2015-02-19 16:26 ` Linus Torvalds
2015-02-19 16:32 ` Rafael David Tinoco
2015-02-19 16:59 ` Linus Torvalds
2015-02-19 17:30 ` Rafael David Tinoco
2015-02-19 17:39 ` Linus Torvalds
2015-02-19 20:29 ` Linus Torvalds
2015-02-19 21:59 ` Linus Torvalds
2015-02-19 22:45 ` Linus Torvalds
2015-03-31 3:15 ` Chris J Arges
2015-03-31 4:28 ` Linus Torvalds
2015-03-31 10:56 ` [debug PATCHes] " Ingo Molnar
2015-03-31 22:38 ` Chris J Arges
2015-04-01 12:39 ` Ingo Molnar
2015-04-01 14:10 ` Chris J Arges
2015-04-01 14:55 ` Ingo Molnar
2015-03-31 4:46 ` Linus Torvalds
2015-03-31 15:08 ` Linus Torvalds
2015-03-31 22:23 ` Chris J Arges
2015-03-31 23:07 ` Linus Torvalds
2015-04-01 14:32 ` Chris J Arges
2015-04-01 15:36 ` Linus Torvalds
2015-04-02 9:55 ` Ingo Molnar
2015-04-02 17:35 ` Linus Torvalds
2015-04-01 12:43 ` Ingo Molnar
2015-04-01 16:10 ` Chris J Arges
2015-04-01 16:14 ` Linus Torvalds
2015-04-01 21:59 ` Chris J Arges
2015-04-02 17:31 ` Linus Torvalds
2015-04-02 18:26 ` Ingo Molnar
2015-04-02 18:51 ` Chris J Arges
2015-04-02 19:07 ` Ingo Molnar
2015-04-02 20:57 ` Linus Torvalds
2015-04-02 21:13 ` Chris J Arges
2015-04-03 5:43 ` [PATCH] smp/call: Detect stuck CSD locks Ingo Molnar
2015-04-03 5:47 ` Ingo Molnar
2015-04-06 16:58 ` Chris J Arges
2015-04-06 17:32 ` Linus Torvalds
2015-04-07 9:21 ` Ingo Molnar
2015-04-07 20:59 ` Chris J Arges
2015-04-07 21:15 ` Linus Torvalds
2015-04-08 6:47 ` Ingo Molnar
2015-04-13 3:56 ` Chris J Arges
2015-04-13 6:14 ` Ingo Molnar
2015-04-15 19:54 ` Chris J Arges
2015-04-16 11:04 ` Ingo Molnar
2015-04-16 15:58 ` Chris J Arges
2015-04-16 16:31 ` Ingo Molnar
2015-04-29 21:08 ` Chris J Arges
2015-05-11 14:00 ` Ingo Molnar
2015-05-20 18:19 ` Chris J Arges
2015-04-03 5:45 ` smp_call_function_single lockups Ingo Molnar
2015-04-06 17:23 ` Chris J Arges
2015-02-20 9:30 ` Ingo Molnar
2015-02-20 16:49 ` Linus Torvalds
2015-02-20 19:41 ` Ingo Molnar
2015-02-20 20:03 ` Linus Torvalds
2015-02-20 20:11 ` Ingo Molnar [this message]
2015-03-20 10:15 ` Peter Zijlstra
2015-03-20 16:26 ` Linus Torvalds
2015-03-20 17:14 ` Mike Galbraith
2015-04-01 14:22 ` Frederic Weisbecker
2015-04-18 10:13 ` [tip:locking/urgent] smp: Fix smp_call_function_single_async() locking tip-bot for Linus Torvalds
2015-02-22 8:59 smp_call_function_single lockups Daniel J Blueman
2015-02-22 10:37 ` Ingo Molnar
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