From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from hera.kernel.org ([140.211.167.34]:59772 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751254Ab0KRGeM (ORCPT ); Thu, 18 Nov 2010 01:34:12 -0500 Message-ID: <4CE4C8DD.6010806@kernel.org> Date: Thu, 18 Nov 2010 07:34:05 +0100 From: Tejun Heo MIME-Version: 1.0 To: Johannes Berg CC: Ben Greear , linux-wireless@vger.kernel.org Subject: Re: [PATCH] mac80211: Fix deadlock in ieee80211_do_stop. References: <1289592426-5367-1-git-send-email-greearb@candelatech.com> <1289594998.3736.11.camel@jlt3.sipsolutions.net> <4CDDAA3B.9090007@candelatech.com> <1289596096.3736.13.camel@jlt3.sipsolutions.net> <4CDE699B.70401@kernel.org> <4CE1A344.7040201@candelatech.com> <4CE292F7.4090200@kernel.org> <1289929258.3673.1.camel@jlt3.sipsolutions.net> <4CE396A9.1050908@kernel.org> <1290020005.3777.6.camel@jlt3.sipsolutions.net> In-Reply-To: <1290020005.3777.6.camel@jlt3.sipsolutions.net> Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hello, On 11/17/2010 07:53 PM, Johannes Berg wrote: >> WQ_NON_REENTRANT doesn't guarantee ordered execution but it guarantees >> that a single work is not executed concurrently on multiple CPUs. I'm >> not sure whether this would be safe for the workqueue used by mac80211 >> but it should let us know whether the workqueue is choked due to a >> work which is executing for long time. In the long run, if using non >> reentrant is safe for mac80211, using it would be much better. > > No, I don't think it's safe for mac80211. I see. In the longer run tho, it would be much better to convert to NRT workqueue. The behavior would be more robust with much lower latencies. Thanks. -- tejun