From: Andi Kleen <andi@firstfloor.org>
To: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC 4/9] Atomic reclaim: Save irq flags in vmscan.c
Date: Tue, 14 Aug 2007 22:33:29 +0200 [thread overview]
Message-ID: <20070814203329.GA22202@one.firstfloor.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0708141209270.29498@schroedinger.engr.sgi.com>
> There are other lock interactions that may cause problems. If we do not
> switch to the saving of irq flags then all involved spinlocks must become
> trylocks because the interrupt could have happened while the spinlock is
> held. So interrupts must be disabled on locks acquired during an
> interrupt.
I was thinking of a per cpu flag that is set before and unset after
taking the lock in process context. If the flag is set the interrupt
will never try to take the spinlock and return NULL instead.
That should be equivalent to cli/sti for this special case.
-Andi
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next prev parent reply other threads:[~2007-08-14 20:33 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-14 15:30 [RFC 0/9] Reclaim during GFP_ATOMIC allocs Christoph Lameter
2007-08-14 15:30 ` [RFC 1/9] Allow reclaim via __GFP_NOMEMALLOC reclaim Christoph Lameter
2007-08-14 15:30 ` [RFC 2/9] Use NOMEMALLOC reclaim to allow reclaim if PF_MEMALLOC is set Christoph Lameter
2007-08-18 7:10 ` Pavel Machek
2007-08-20 19:00 ` Christoph Lameter
2007-08-20 20:17 ` Peter Zijlstra
2007-08-20 20:27 ` Christoph Lameter
2007-08-20 21:14 ` Peter Zijlstra
2007-08-20 21:17 ` Christoph Lameter
2007-08-21 14:07 ` Peter Zijlstra
2007-08-21 0:39 ` Nick Piggin
2007-08-21 14:07 ` Peter Zijlstra
2007-08-23 3:38 ` Nick Piggin
2007-08-23 9:26 ` Peter Zijlstra
2007-08-23 10:11 ` Nikita Danilov
2007-08-23 13:58 ` Peter Zijlstra
2007-08-24 4:00 ` Nick Piggin
2007-08-14 15:30 ` [RFC 3/9] Make cond_rescheds conditional on __GFP_WAIT Christoph Lameter
2007-08-14 15:30 ` [RFC 4/9] Atomic reclaim: Save irq flags in vmscan.c Christoph Lameter
2007-08-14 20:02 ` Andi Kleen
2007-08-14 19:12 ` Christoph Lameter
2007-08-14 20:05 ` Peter Zijlstra
2007-08-14 20:34 ` Andi Kleen
2007-08-14 20:33 ` Andi Kleen [this message]
2007-08-14 20:42 ` Christoph Lameter
2007-08-14 20:44 ` Andi Kleen
2007-08-14 21:15 ` Christoph Lameter
2007-08-14 21:23 ` Andi Kleen
2007-08-14 21:26 ` Christoph Lameter
2007-08-14 21:29 ` Andi Kleen
2007-08-14 21:37 ` Christoph Lameter
2007-08-14 21:44 ` Andi Kleen
2007-08-14 21:48 ` Christoph Lameter
2007-08-14 21:56 ` Andi Kleen
2007-08-14 22:07 ` Christoph Lameter
2007-08-14 22:16 ` Andi Kleen
2007-08-14 22:20 ` Christoph Lameter
2007-08-14 22:21 ` Andi Kleen
2007-08-14 22:41 ` Christoph Lameter
2007-08-14 15:30 ` [RFC 5/9] Save irqflags on taking the mapping lock Christoph Lameter
2007-08-14 15:30 ` [RFC 6/9] Disable irqs on taking the private_lock Christoph Lameter
2007-08-14 15:30 ` [RFC 7/9] Save flags in swap.c Christoph Lameter
2007-08-14 15:30 ` [RFC 8/9] Reclaim on an atomic allocation if necessary Christoph Lameter
2007-08-14 15:30 ` [RFC 9/9] Testing: Perform GFP_ATOMIC overallocation Christoph Lameter
2007-08-16 2:49 ` [RFC 0/9] Reclaim during GFP_ATOMIC allocs Nick Piggin
2007-08-16 20:24 ` Christoph Lameter
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