From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: GFP_ATOMIC page allocation failures. Date: Thu, 03 Apr 2008 14:20:03 -0400 Message-ID: <47F51FD3.604@garzik.org> References: <20080401235609.GA6947@codemonkey.org.uk> <20080402103355.77ef22ff.akpm@linux-foundation.org> <47F3CE10.1060903@garzik.org> <200804031657.43895.nickpiggin@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Andrew Morton , Chris Snook , Dave Jones , Linux Kernel , NetDev , David Miller , Linus Torvalds To: Nick Piggin Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:49546 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756953AbYDCSUR (ORCPT ); Thu, 3 Apr 2008 14:20:17 -0400 In-Reply-To: <200804031657.43895.nickpiggin@yahoo.com.au> Sender: netdev-owner@vger.kernel.org List-ID: Nick Piggin wrote: > 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. No objections here, and agreed on all points. Though IMO adding __GFP_NOWARN to netdev_alloc_skb() falls into that category (should not generally be in a driver or driver API). Jeff