From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] CIFS: make cifsd (more) Date: Sat, 30 Jun 2007 09:42:09 +0100 Message-ID: <20070630084209.GA21186@infradead.org> References: <524f69650706251525g7b17ea02o5fb3e637615fe542@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, jlayton@redhat.com, linux-kernel@vger.kernel.org, linux-cifs-client@lists.samba.org, netdev@vger.kernel.org To: Steve French Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:58954 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753153AbXF3ImK (ORCPT ); Sat, 30 Jun 2007 04:42:10 -0400 Content-Disposition: inline In-Reply-To: <524f69650706251525g7b17ea02o5fb3e637615fe542@mail.gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Mon, Jun 25, 2007 at 05:25:00PM -0500, Steve French wrote: > Jeff, > Not seeing any objections to your revised approach (to not allowing > signals for cifsd kernel thread), I just merged something similar to > your patch to the cifs-2.6.git tree (also fixed some nearby lines that > went past 80 columns). Ok, I'm back to this. As I said mixing force_sig with the kthread infrastructure is a bad idea. The proper short-term (aka 2.6.22) fix is to revert the kthread conversion for this particular thread. Just go back to what worked before. Now the right fix is a lot more complicated and involved: Stop using blocking recvmsg (or read) in kernel threads! If you look at what the other consumers of networking reads from kernel threads do is they either use tcp_read_sock and hooks into the sk_ callbacks which would be nice for high performance reads in cifs aswell, but probably not the demultiplexer thread, or they use MSG_DONTWAIT to avoid this problems and deal with the blocking behaviour on a higher level.