linux-kernel - Re: GFP_ATOMIC page allocation failures.

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Date:	Thu, 3 Apr 2008 16:57:43 +1100
From:	Nick Piggin <nickpiggin@...oo.com.au>
To:	Jeff Garzik <jeff@...zik.org>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Chris Snook <csnook@...hat.com>,
	Dave Jones <davej@...emonkey.org.uk>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	NetDev <netdev@...r.kernel.org>,
	David Miller <davem@...emloft.net>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: GFP_ATOMIC page allocation failures.

On Thursday 03 April 2008 05:18, Jeff Garzik wrote:

> Turning to Nick's comment,
>
> > It's still actually nice to know how often it is happening even for
> > these known good sites because too much can indicate a problem and
> > that you could actually bring performance up by tuning some things.
>
> then create a counter or acculuation buffer somewhere.
>
> We don't need spew every time there is memory pressure of this magnitude.

Not a complete solution. Counter would be nice, but you need backtraces
and want a way to more proactively warn the user/tester/developer.

I agree that I don't exactly like adding nowarns around, and I don't think
places like driver writers should have to know about this stuff.


> IMO there are much better ways than printk(), to inform tasks, and
> humans, of allocation failures.

I think with a tweaked warning message, a ratelimited printk is OK.
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