Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422644AbWCWSVe (ORCPT ); Thu, 23 Mar 2006 13:21:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422645AbWCWSVe (ORCPT ); Thu, 23 Mar 2006 13:21:34 -0500 Received: from mail.tv-sign.ru ([213.234.233.51]:42646 "EHLO several.ru") by vger.kernel.org with ESMTP id S1422644AbWCWSVe (ORCPT ); Thu, 23 Mar 2006 13:21:34 -0500 Message-ID: <4422E670.1E88A0F8@tv-sign.ru> Date: Thu, 23 Mar 2006 21:18:24 +0300 From: Oleg Nesterov X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.2.20 i686) X-Accept-Language: en MIME-Version: 1.0 To: Ravikiran G Thirumalai Cc: Christoph Lameter , Shai Fultheim , Nippun Goel , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [rfc][patch] Avoid taking global tasklist_lock for single threadedprocess at getrusage() References: <43B2874F.F41A9299@tv-sign.ru> <20051228183345.GA3755@localhost.localdomain> <20051228225752.GB3755@localhost.localdomain> <43B57515.967F53E3@tv-sign.ru> <20060104231600.GA3664@localhost.localdomain> <43BD70AD.21FC6862@tv-sign.ru> <20060106094627.GA4272@localhost.localdomain> <20060106194623.GA4078@localhost.localdomain> <441EEEC8.D4D9C40A@tv-sign.ru> <20060322221844.GA3300@localhost.localdomain> Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 874 Lines: 25 Ravikiran G Thirumalai wrote: > > __exit_signal > cleanup_sighand(tsk); > kmem_cache_free(sighand) > spin_unlock(sighand->lock) > > It looked suspicious to me until I realised sighand cache now had > SLAB_DESTROY_BY_RCU. Can we please add comments (at cleanup_sighand or > __exit_signal) to make it a bit clearer for people like me :) Yes, this is really confusing, see also http://marc.theaimsgroup.com/?l=linux-kernel&m=114089590923893 I'll send a cleanup patch soon. > How is the following patch to avoid tasklist lock completely at getrusage? I think this patch is correct, thanks. Oleg. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/