From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Klassert Subject: Re: [PATCH] flow_cache_flush soft lockup with heavy ipsec traffic Date: Wed, 9 Nov 2011 14:43:48 +0100 Message-ID: <20111109134348.GD10138@secunet.com> References: <4EBA7038.4050702@mt.lv> <1320844564.3916.4.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Maris Paupe , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from a.mx.secunet.com ([195.81.216.161]:40274 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752021Ab1KINny (ORCPT ); Wed, 9 Nov 2011 08:43:54 -0500 Content-Disposition: inline In-Reply-To: <1320844564.3916.4.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Nov 09, 2011 at 02:16:04PM +0100, Eric Dumazet wrote: > > Sorry, I dont understand your patch. > > BH are disabled by the spin_lock_bh() call. > > Once flow_cache_entry are in garbage list, nothing but garbage collector > can access them. I see no possible deadlock. Or there is a bug somewhere > and your patch avoid it. > > Whole point of using a work queue to perform garbage collect was to not > hold BH too long (allowing sotirq to process incoming packets), so you > basically remove what was done in commit 8e4795605d. > I guess this tries to address a problem that was already discussed here: http://patchwork.ozlabs.org/patch/116457/