From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Ming Lei <tom.leiming@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-embedded@vger.kernel.org, a.p.zijlstra@chello.nl,
linux-kernel@vger.kernel.org
Subject: Re: [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning
Date: Sun, 23 May 2010 15:13:01 +0100 [thread overview]
Message-ID: <20100523141300.GD950@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <AANLkTikRp0EHxshKYq39p18ymoRNAtyHrNm3yq6A49-r@mail.gmail.com>
On Sun, May 23, 2010 at 09:44:20PM +0800, Ming Lei wrote:
> 2010/5/23 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> >> ENTRY(ret_to_user)
> >> ret_slow_syscall:
> >> - disable_irq @ disable interrupts
> >> + disable_irq_notrace @ disable interrupts
> >
> > I think this one does need to be traced - the pending work functions are
> > all C code which could call back into lockdep.
>
> If there are pending works, schedule will be called to give cpu to it,
> I wonder why the work function to be scheduled will be run with irq
> disabled. Seems we should enable irq again before calling schedule,
> not sure.
No. I'm talking about things like do_notify_resume().
I think the above should be left as-is, so that as far as lockdep is
concerned, IRQs are off while userspace runs. What happens between
returning to userspace and re-entering the kernel has no bearing what
so ever on lockdep.
next prev parent reply other threads:[~2010-05-23 14:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-23 11:48 [RESEND PATCH] ARM: fix 'unannotated irqs-on' lockdep warning tom.leiming
2010-05-23 12:38 ` Russell King - ARM Linux
2010-05-23 13:44 ` Ming Lei
2010-05-23 14:13 ` Russell King - ARM Linux [this message]
2010-05-23 15:07 ` Ming Lei
2010-05-23 19:47 ` Russell King - ARM Linux
2010-05-24 3:23 ` Ming Lei
2010-05-24 7:19 ` Russell King - ARM Linux
2010-05-24 10:14 ` Russell King - ARM Linux
2010-05-24 14:20 ` Ming Lei
2010-05-24 14:45 ` Russell King - ARM Linux
2010-05-24 15:19 ` Ming Lei
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