From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Mackall Subject: Re: 2.6.23 WARNING: at kernel/softirq.c:139 local_bh_enable() Date: Fri, 23 Nov 2007 13:20:33 -0600 Message-ID: <20071123192032.GB19691@waste.org> References: <4745DCD7.8070805@simon.arlott.org.uk> <20071123002157.cb27f4a1.akpm@linux-foundation.org> <20071123105518.GA22062@2ka.mipt.ru> <20071123170756.GV19691@waste.org> <20071123175757.GA23991@2ka.mipt.ru> <20071123185943.GZ19691@waste.org> <20071123191524.GA6273@2ka.mipt.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , Simon Arlott , Linux Kernel Mailing List , netdev@vger.kernel.org, Ingo Molnar To: Evgeniy Polyakov Return-path: Received: from waste.org ([66.93.16.53]:39037 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752738AbXKWTbk (ORCPT ); Fri, 23 Nov 2007 14:31:40 -0500 Content-Disposition: inline In-Reply-To: <20071123191524.GA6273@2ka.mipt.ru> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, Nov 23, 2007 at 10:15:24PM +0300, Evgeniy Polyakov wrote: > On Fri, Nov 23, 2007 at 12:59:43PM -0600, Matt Mackall (mpm@selenic.com) wrote: > > So I'd be surprised if that was a problem. But I can imagine having > > problems for skbs without destructors which run into one of these in > > __kfree_skb: > > > > dst_release > > secpath_put > > nf_conntrack_put > > nf_conntrack_put_reasm > > nf_bridge_put > > > > ..some or all of which assume a softirq context. > > bridging is ok, others require softirq context. > I've sent a patch (the last one should be ok) to guard against xfrm and > connection tracking. > > > > No matter if we are under memory pressure or whatever - it is not > > > allowed - a lot of skbs are supposed to be freed in softirq context, > > > that is why dev_kfree_skb_any() exists. > > > > Some skbs we definitely -can- free in irq context. The only ones we > > care about are the ones generated by netpoll. If there's a reason you > > think netpoll's own skbs can't be freed, please describe it. > > Only some and to distinguish them we can not use destructor - if it is > set (even empty function) it will fire an alarm. Yep, please look at the patch I just posted. -- Mathematics is the supreme nostalgia of our time.