From patchwork Thu Aug 4 09:53:08 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 9263229 X-Patchwork-Delegate: snitzer@redhat.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B39DD60754 for ; Thu, 4 Aug 2016 10:12:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A47A82832B for ; Thu, 4 Aug 2016 10:12:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 990E5283AC; Thu, 4 Aug 2016 10:12:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mx5-phx2.redhat.com (mx5-phx2.redhat.com [209.132.183.37]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 115412832B for ; Thu, 4 Aug 2016 10:12:36 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by mx5-phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u74A8oio014946; Thu, 4 Aug 2016 06:08:51 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id u74A8nD3019448 for ; Thu, 4 Aug 2016 06:08:49 -0400 Received: from mx1.redhat.com (ext-mx04.extmail.prod.ext.phx2.redhat.com [10.5.110.28]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u74A8nmR022442 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Thu, 4 Aug 2016 06:08:49 -0400 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 53B9B821C7 for ; Thu, 4 Aug 2016 10:08:48 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 0EB71ACBA for ; Thu, 4 Aug 2016 10:08:47 +0000 (UTC) To: dm-devel@redhat.com References: <536022978.7668211.1470060125271.JavaMail.zimbra@redhat.com> <931235537.7668834.1470060339483.JavaMail.zimbra@redhat.com> <1264951811.7684268.1470065187014.JavaMail.zimbra@redhat.com> <17da3ab0-233a-2cec-f921-bfd42c953ccc@sandisk.com> <20160801175948.GA6685@redhat.com> <20160801204628.GA94704@redhat.com> <8e265fcc-8021-830e-ffcb-23a8a28ec247@sandisk.com> <20160802174533.GA18714@redhat.com> <1a460c29-1530-d3e1-25ba-736d86aff12e@sandisk.com> <20160803004013.GA19956@redhat.com> From: Hannes Reinecke Message-ID: Date: Thu, 4 Aug 2016 11:53:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2 MIME-Version: 1.0 In-Reply-To: X-Greylist: Sender IP whitelisted by DNSRBL, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 04 Aug 2016 10:08:48 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 04 Aug 2016 10:08:48 +0000 (UTC) for IP:'195.135.220.15' DOMAIN:'mx2.suse.de' HELO:'mx2.suse.de' FROM:'hare@suse.de' RCPT:'' X-RedHat-Spam-Score: -3.146 (BAYES_50, DCC_REPUT_00_12, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, SPF_PASS) 195.135.220.15 mx2.suse.de 195.135.220.15 mx2.suse.de X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Scanned-By: MIMEDefang 2.78 on 10.5.110.28 X-loop: dm-devel@redhat.com Subject: Re: [dm-devel] dm-mq and end_clone_request() X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Virus-Scanned: ClamAV using ClamSMTP On 08/03/2016 06:55 PM, Bart Van Assche wrote: > On 08/02/2016 05:40 PM, Mike Snitzer wrote: >> But I asked you to run the v4.7 kernel patches I >> pointed to _without_ any of your debug patches. > > I need several patches to fix bugs that are not related to the device > mapper, e.g. "sched: Avoid that __wait_on_bit_lock() hangs" > (https://lkml.org/lkml/2016/8/3/289). > Hmm. Can you test with this patch? Reasoning: The original check for dm_noflush_suspending() was for bio-based drivers, which needed to queue I/O within the device-mapper core. So during suspend this I/O would keep a reference to the device-mapper core and the table couldn't be swapped. For request-based multipathing, however, the I/O is _never_ held within the device-mapper core but rather pushed back to the request queue. IE even for pushback the I/O will never hold a reference to the device-mapper core, and the tables can be swapped irrespective of the 'dm_noflush_suspend()' setting. Or that's the idea, at least :-) Yes Mike, I know, it's not going to work with bio-based multipathing. But this is just for figuring out where the real issue is. Cheers, Hannes diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 7790a70..9daed03 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -439,8 +439,7 @@ static int must_push_back(struct multipath *m) { return (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || ((test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) != - test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) && - dm_noflush_suspending(m->ti))); + test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags))); } /*