From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [PATCH 06/33] mm: allow PF_MEMALLOC from softirq context Date: Wed, 31 Oct 2007 21:49:24 +1100 Message-ID: <200710312149.25296.nickpiggin@yahoo.com.au> References: <20071030160401.296770000@chello.nl> <200710311451.56747.nickpiggin@yahoo.com.au> <1193827359.27652.129.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no To: Peter Zijlstra Return-path: Received: from smtp102.mail.mud.yahoo.com ([209.191.85.212]:47220 "HELO smtp102.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754372AbXJaMCz (ORCPT ); Wed, 31 Oct 2007 08:02:55 -0400 In-Reply-To: <1193827359.27652.129.camel@twins> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wednesday 31 October 2007 21:42, Peter Zijlstra wrote: > On Wed, 2007-10-31 at 14:51 +1100, Nick Piggin wrote: > > On Wednesday 31 October 2007 03:04, Peter Zijlstra wrote: > > > Allow PF_MEMALLOC to be set in softirq context. When running softirqs > > > from a borrowed context save current->flags, ksoftirqd will have its > > > own task_struct. > > > > What's this for? Why would ksoftirqd pick up PF_MEMALLOC? (I guess > > that some networking thing must be picking it up in a subsequent patch, > > but I'm too lazy to look!)... Again, can you have more of a rationale in > > your patch headers, or ref the patch that uses it... thanks > > Right, I knew I was forgetting something in these changelogs. > > The network stack does quite a bit of packet processing from softirq > context. Once you start swapping over network, some of the packets want > to be processed under PF_MEMALLOC. Hmm... what about processing from interrupt context?