[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1219910257.6443.6.camel@twins>
Date: Thu, 28 Aug 2008 09:57:37 +0200
From: Peter Zijlstra <a.p.zijlstra@...llo.nl>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: aneesh.kumar@...ux.vnet.ibm.com, cmm@...ibm.com, tytso@....edu,
sandeen@...hat.com, linux-ext4@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH -V3 01/11] percpu_counters: make fbc->count read atomic
on 32 bit architecture
On Wed, 2008-08-27 at 14:22 -0700, Andrew Morton wrote:
> btw, what the heck is percpu_counter_init_irq()? Some mysterious
> lockdep-specific thing?
>
> <does git-fiddle. Oh. crappy changelog.>
>
> I let that one leak through uncommented. Must be getting old.
> Probably it will need an EXPORT_SYMBOL() sometime.
Basically all it does it break the percpu_counter lock into two classes.
One for the irq-unsafe users and one for the irq-safe users. Without
this lockdep goes splat complaining about irq recursion deadlocks and
the like between these two separate users.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists