From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754942AbaCLQQ0 (ORCPT ); Wed, 12 Mar 2014 12:16:26 -0400 Received: from smtp03.stone-is.org ([87.238.162.6]:44002 "EHLO smtpgw.stone-is.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753198AbaCLQQW (ORCPT ); Wed, 12 Mar 2014 12:16:22 -0400 X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network X-No-Relay: not in my network Message-ID: <53208851.8080103@acm.org> Date: Wed, 12 Mar 2014 17:16:17 +0100 From: Bart Van Assche User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Alexander Gordeev CC: Jens Axboe , Kent Overstreet , Shaohua Li , Christoph Hellwig , Mike Christie , linux-kernel Subject: Re: [PATCH] percpu_ida: Handle out-of-tags gracefully References: <531DC851.5060400@acm.org> <20140311135137.GA22995@dhcp-26-207.brq.redhat.com> <531F518A.1070808@acm.org> <20140311204826.GA30105@dhcp-26-207.brq.redhat.com> <53200B2E.4060805@acm.org> <20140312152140.GA14305@dhcp-26-207.brq.redhat.com> In-Reply-To: <20140312152140.GA14305@dhcp-26-207.brq.redhat.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/12/14 16:21, Alexander Gordeev wrote: > While 'remote->nr_free' could be dropped on another CPU it still does not > explain how steal_tags() enters the loop, but fails to locate 'cpus_have_tags' > count of bits. > > So although v2 of your patch fixes the crash it does not address the root > cause IMHO. Hmm ... you are probably right. I will analyze this further and see what I can come up with. Bart.