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From: Tejun Heo <tj@kernel.org>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peterz@infradead.org>,
	Jeff Mahoney <jeffm@suse.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Tony Luck <tony.luck@intel.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	linux-ia64@vger.kernel.org
Subject: Re: [PATCH 1/2] percpu: allow pcpu_alloc() to be called with IRQs
Date: Tue, 27 Oct 2009 12:55:27 +0000	[thread overview]
Message-ID: <4AE6EDBF.7040905@kernel.org> (raw)
In-Reply-To: <alpine.LSU.2.00.0910271328340.19847@wotan.suse.de>

Jiri Kosina wrote:
> pcpu_alloc() and pcpu_extend_area_map() perform a series of
> spin_lock_irq()/spin_unlock_irq() calls, which make them unsafe
> with respect to being called from contexts which have IRQs off.
> 
> This patch converts the code to perform save/restore of flags instead,
> making pcpu_alloc() (or __alloc_percpu() respectively) to be called
> from early kernel startup stage, where IRQs are off.
> 
> This is needed for proper initialization of per-cpu rq_weight data from
> sched_init().
> 
> Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Acked-by: Tejun Heo <tj@kernel.org>

I'll wait for response on the series and push it through percpu#fixes
tomorrow if there's no objection.

Thanks.

-- 
tejun

WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peterz@infradead.org>,
	Jeff Mahoney <jeffm@suse.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Tony Luck <tony.luck@intel.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	linux-ia64@vger.kernel.org
Subject: Re: [PATCH 1/2] percpu: allow pcpu_alloc() to be called with IRQs off
Date: Tue, 27 Oct 2009 13:55:27 +0100	[thread overview]
Message-ID: <4AE6EDBF.7040905@kernel.org> (raw)
In-Reply-To: <alpine.LSU.2.00.0910271328340.19847@wotan.suse.de>

Jiri Kosina wrote:
> pcpu_alloc() and pcpu_extend_area_map() perform a series of
> spin_lock_irq()/spin_unlock_irq() calls, which make them unsafe
> with respect to being called from contexts which have IRQs off.
> 
> This patch converts the code to perform save/restore of flags instead,
> making pcpu_alloc() (or __alloc_percpu() respectively) to be called
> from early kernel startup stage, where IRQs are off.
> 
> This is needed for proper initialization of per-cpu rq_weight data from
> sched_init().
> 
> Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Acked-by: Tejun Heo <tj@kernel.org>

I'll wait for response on the series and push it through percpu#fixes
tomorrow if there's no objection.

Thanks.

-- 
tejun

  reply	other threads:[~2009-10-27 12:55 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-27 12:32 [PATCH 1/2] percpu: allow pcpu_alloc() to be called with IRQs off Jiri Kosina
2009-10-27 12:32 ` Jiri Kosina
2009-10-27 12:55 ` Tejun Heo [this message]
2009-10-27 12:55   ` Tejun Heo
2009-10-27 13:04   ` [PATCH 1/2] percpu: allow pcpu_alloc() to be called with IRQs Ingo Molnar
2009-10-27 13:04     ` [PATCH 1/2] percpu: allow pcpu_alloc() to be called with IRQs off Ingo Molnar
2009-10-28 14:59   ` [PATCH 1/2] percpu: allow pcpu_alloc() to be called with IRQs Tejun Heo
2009-10-28 14:59     ` [PATCH 1/2] percpu: allow pcpu_alloc() to be called with IRQs off Tejun Heo

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