Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932625Ab3ICI5R (ORCPT ); Tue, 3 Sep 2013 04:57:17 -0400 Received: from mail-bk0-f41.google.com ([209.85.214.41]:57847 "EHLO mail-bk0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932557Ab3ICI5P (ORCPT ); Tue, 3 Sep 2013 04:57:15 -0400 Message-ID: <5225A466.2080303@colorfullife.com> Date: Tue, 03 Sep 2013 10:57:10 +0200 From: Manfred Spraul User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130805 Thunderbird/17.0.8 MIME-Version: 1.0 To: Vineet Gupta CC: Linus Torvalds , Davidlohr Bueso , Sedat Dilek , Davidlohr Bueso , linux-next , LKML , Stephen Rothwell , Andrew Morton , linux-mm , Andi Kleen , Rik van Riel , Jonathan Gonzalez Subject: Re: ipc-msg broken again on 3.11-rc7? References: <1372202983.1888.22.camel@buesod1.americas.hpqcorp.net> <521DE5D7.4040305@synopsys.com> <52205597.3090609@synopsys.com> <5224BCF6.2080401@colorfullife.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1413 Lines: 38 On 09/03/2013 10:44 AM, Vineet Gupta wrote: >> b) Could you check that it is not just a performance regression? >> Does ./msgctl08 1000 16 hang, too? > Nope that doesn't hang. The minimal configuration that hangs reliably is msgctl > 50000 2 > > With this config there are 3 processes. > ... > 555 554 root S 1208 0.4 0 0.0 ./msgctl08 50000 2 > 554 551 root S 1208 0.4 0 0.0 ./msgctl08 50000 2 > 551 496 root S 1208 0.4 0 0.0 ./msgctl08 50000 2 > ... > > [ARCLinux]$ cat /proc/551/stack > [<80aec3c6>] do_wait+0xa02/0xc94 > [<80aecad2>] SyS_wait4+0x52/0xa4 > [<80ae24fc>] ret_from_system_call+0x0/0x4 > > [ARCLinux]$ cat /proc/555/stack > [<80c2950e>] SyS_msgrcv+0x252/0x420 > [<80ae24fc>] ret_from_system_call+0x0/0x4 > > [ARCLinux]$ cat /proc/554/stack > [<80c28c82>] do_msgsnd+0x116/0x35c > [<80ae24fc>] ret_from_system_call+0x0/0x4 > > Is this a case of lost wakeup or some such. I'm running with some more diagnostics > and will report soon ... What is the output of ipcs -q? Is the queue full or empty when it hangs? I.e. do we forget to wake up a receiver or forget to wake up a sender? -- Manfred -- 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/