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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: James Simmons <jsimmons@infradead.org>
Cc: Linus Torvalds <torvalds@transmeta.com>,
	Linux Fbdev development list
	<linux-fbdev-devel@lists.sourceforge.net>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [BK FBDEV] A few more updates.
Date: 25 Mar 2003 19:35:54 +0100	[thread overview]
Message-ID: <1048617354.10476.6.camel@zion.wanadoo.fr> (raw)
In-Reply-To: <1048616901.10476.3.camel@zion.wanadoo.fr>

On Tue, 2003-03-25 at 19:28, Benjamin Herrenschmidt wrote:

> You "fixed" it by using GFP_ATOMIC but didn't test the result of
> kmalloc. That is very bad. GFP_ATOMIC can fail (return NULL), thus
> you will crash the kernel under high memory pressure.
> 
> I think the proper fix is, as you asked me, using a workqueue,
> that way, you can both use GFP_KERNEL allocations, and avoid
> the spinlock you added to fbmem.c, thus letting the fb_sync()
> ops on fbdev's be able to block.

Well, actually, creating a workqueue would be overhead since
it involves one kernel thread per CPU. After more thinking &
discussion, I beleive you shall rather use keventd existing
workqueue (schedule_work() will do that)

Ben.



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  reply	other threads:[~2003-03-25 18:36 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-03-25 18:32 [BK FBDEV] A few more updates James Simmons
2003-03-25 18:01 ` Russell King
2003-03-25 18:04   ` James Simmons
2003-03-25 18:28 ` Benjamin Herrenschmidt
2003-03-25 18:35   ` Benjamin Herrenschmidt [this message]
2003-03-25 19:48     ` James Simmons
2003-03-25 20:10       ` Benjamin Herrenschmidt
2003-03-25 20:14         ` James Simmons
2003-03-25 18:44   ` James Simmons
2003-03-26  3:37 ` Antonino Daplas
2003-03-26  5:34   ` James Simmons
2003-03-26  9:53     ` Antonino Daplas
2003-03-26 10:20     ` Antonino Daplas
  -- strict thread matches above, loose matches on Subject: below --
2003-03-26 10:42 Petr Vandrovec
2003-03-26 11:20 ` Antonino Daplas
2003-03-26 10:53 Petr Vandrovec

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