From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>, Michal Hocko <mhocko@suse.cz>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Lai Jiangshan <jiangshanlai@gmail.com>, Shaohua Li <shli@fb.com>,
linux-mm <linux-mm@kvack.org>
Subject: Re: [GIT PULL] workqueue fixes for v4.3-rc5
Date: Mon, 19 Oct 2015 05:51:50 +0200 [thread overview]
Message-ID: <1445226710.15861.28.camel@gmail.com> (raw)
In-Reply-To: <20151014202448.GE12799@mtj.duckdns.org>
On Wed, 2015-10-14 at 16:24 -0400, Tejun Heo wrote:
> But in terms of API consistency, it sucks to have queue_work()
> guarantee local queueing but not queue_delayed_work(). The ideal
> situation would be updating both so that neither guarantees.
You don't have to change anything to have neither guarantee local
queueing. Called from a preemptible context, local means any CPU in
->cpus_allowed... which makes WORK_CPU_UNBOUND mean what one would
imagine WORK_CPU_UNBOUND to mean, not bound to any particular cpu.
sh-16017 3.N.. 1510500545us : queue_work_on: golly, migrated cpu7 -> cpu3 -- target cpu8
sh-16017 3.N.. 1510500550us : <stack trace>
=> tty_flip_buffer_push
=> pty_write
=> n_tty_write
=> tty_write
=> __vfs_write
=> vfs_write
=> SyS_write
=> entry_SYSCALL_64_fastpath
That was with a udelay(100) prior to disabling interrupts, but that just
makes it easier.
-Mike
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WARNING: multiple messages have this Message-ID (diff)
From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>, Michal Hocko <mhocko@suse.cz>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Lai Jiangshan <jiangshanlai@gmail.com>, Shaohua Li <shli@fb.com>,
linux-mm <linux-mm@kvack.org>
Subject: Re: [GIT PULL] workqueue fixes for v4.3-rc5
Date: Mon, 19 Oct 2015 05:51:50 +0200 [thread overview]
Message-ID: <1445226710.15861.28.camel@gmail.com> (raw)
In-Reply-To: <20151014202448.GE12799@mtj.duckdns.org>
On Wed, 2015-10-14 at 16:24 -0400, Tejun Heo wrote:
> But in terms of API consistency, it sucks to have queue_work()
> guarantee local queueing but not queue_delayed_work(). The ideal
> situation would be updating both so that neither guarantees.
You don't have to change anything to have neither guarantee local
queueing. Called from a preemptible context, local means any CPU in
->cpus_allowed... which makes WORK_CPU_UNBOUND mean what one would
imagine WORK_CPU_UNBOUND to mean, not bound to any particular cpu.
sh-16017 3.N.. 1510500545us : queue_work_on: golly, migrated cpu7 -> cpu3 -- target cpu8
sh-16017 3.N.. 1510500550us : <stack trace>
=> tty_flip_buffer_push
=> pty_write
=> n_tty_write
=> tty_write
=> __vfs_write
=> vfs_write
=> SyS_write
=> entry_SYSCALL_64_fastpath
That was with a udelay(100) prior to disabling interrupts, but that just
makes it easier.
-Mike
next prev parent reply other threads:[~2015-10-19 3:51 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-13 21:49 [GIT PULL] workqueue fixes for v4.3-rc5 Tejun Heo
2015-10-14 16:30 ` Linus Torvalds
2015-10-14 16:30 ` Linus Torvalds
2015-10-14 16:57 ` Tejun Heo
2015-10-14 16:57 ` Tejun Heo
2015-10-14 17:36 ` Linus Torvalds
2015-10-14 17:36 ` Linus Torvalds
2015-10-14 17:57 ` Christoph Lameter
2015-10-14 17:57 ` Christoph Lameter
2015-10-14 18:37 ` Linus Torvalds
2015-10-14 18:37 ` Linus Torvalds
2015-10-14 18:58 ` Christoph Lameter
2015-10-14 18:58 ` Christoph Lameter
2015-10-14 19:01 ` Linus Torvalds
2015-10-14 19:01 ` Linus Torvalds
2015-10-14 19:02 ` Tejun Heo
2015-10-14 19:02 ` Tejun Heo
2015-10-14 19:16 ` Linus Torvalds
2015-10-14 19:16 ` Linus Torvalds
2015-10-14 19:38 ` Tejun Heo
2015-10-14 19:38 ` Tejun Heo
2015-10-14 20:10 ` Linus Torvalds
2015-10-14 20:10 ` Linus Torvalds
2015-10-14 20:24 ` Tejun Heo
2015-10-14 20:24 ` Tejun Heo
2015-10-19 3:51 ` Mike Galbraith [this message]
2015-10-19 3:51 ` Mike Galbraith
2015-10-16 19:51 ` [PATCH] vmstat_update: ensure work remains on the same core Chris Metcalf
2015-10-16 19:51 ` Chris Metcalf
2015-10-16 19:54 ` Linus Torvalds
2015-10-16 19:54 ` Linus Torvalds
2015-10-14 18:03 ` [GIT PULL] workqueue fixes for v4.3-rc5 Christoph Lameter
2015-10-14 18:03 ` Christoph Lameter
2015-10-14 18:40 ` Linus Torvalds
2015-10-14 18:40 ` Linus Torvalds
2015-10-14 18:59 ` Christoph Lameter
2015-10-14 18:59 ` Christoph Lameter
2015-10-14 19:10 ` Linus Torvalds
2015-10-14 19:10 ` Linus Torvalds
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