From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1A5CBC433E8 for ; Tue, 28 Jul 2020 10:57:48 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DFB00204EA for ; Tue, 28 Jul 2020 10:57:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="2rqiBWCO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DFB00204EA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=sKrXieyaVMmBaX1+auCL320jkgLv1toJngq7a//V/4U=; b=2rqiBWCO+iY+gcQfaKuJHg1S9 5zgpuRSot08FSUg66zgnFHefZBMIuEHnjtT5D5Gv6pfaMZE2tbv96UejGfOiahcZGzf+44LCv/e9o aw3OsuXbAja8tXz7NqFdj5xfPuJLKGoJugldTikGe5QzLugSqKBa3WfwZRym+Az0Cf3/OmDPcMWJX AsCrvLqGtVXTEH61lEbpwuwAwbl2yrn83p2dUMrcRpS7YDRr5v+RoMobL1xGHmIhBiuv7JTV9zs29 GVP8ZCcifMeTlKPfof5bPn6cHx0du5DnS9nBYtLQUqSTg07T+BmEqc/1yY3IO1JtPvuSEtEhUrwzP o2nMdsFYA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0NIo-0004k1-2Y; Tue, 28 Jul 2020 10:57:46 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0NIm-0004jB-6B for linux-nvme@lists.infradead.org; Tue, 28 Jul 2020 10:57:44 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id AC52D68C4E; Tue, 28 Jul 2020 12:57:41 +0200 (CEST) Date: Tue, 28 Jul 2020 12:57:41 +0200 From: Christoph Hellwig To: Ming Lei Subject: Re: [PATCH v5 1/2] blk-mq: add tagset quiesce interface Message-ID: <20200728105741.GA29763@lst.de> References: <20200727231022.307602-1-sagi@grimberg.me> <20200727231022.307602-2-sagi@grimberg.me> <20200728071859.GA21629@lst.de> <20200728091633.GB1326626@T590> <20200728093326.GC1326626@T590> <44f07df6-3107-3e7f-ee02-7bc43293ee6b@grimberg.me> <6a678d5d-22b2-5238-92c5-d68e2aafeb9e@grimberg.me> <20200728101042.GA1336890@T590> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200728101042.GA1336890@T590> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200728_065744_378707_48DA7175 X-CRM114-Status: GOOD ( 16.45 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jens Axboe , Sagi Grimberg , "Paul E. McKenney" , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, Chao Leng , Keith Busch , Ming Lin , Christoph Hellwig Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Jul 28, 2020 at 06:10:42PM +0800, Ming Lei wrote: > + struct blk_mq_hw_ctx *hctx = (void *)srcu - > + sizeof(struct blk_mq_hw_ctx); I think this should use container_of. > +{ > + struct blk_mq_hw_ctx *hctx; > + unsigned int i; > + > + blk_mq_quiesce_queue_nowait(q); > + > + queue_for_each_hw_ctx(q, hctx, i) { > + WARN_ON_ONCE(!(hctx->flags & BLK_MQ_F_BLOCKING)); > + init_rcu_head(&hctx->srcu->head); We only need to initialize the rcu head once when we allocate the hctx. > + mutex_lock(&set->tag_list_lock); > + if (set->flags & BLK_MQ_F_BLOCKING) { > + int count = 0; > + > + list_for_each_entry(q, &set->tag_list, tag_set_list) > + count++; > + > + atomic_set(&set->quiesce_count, count); > + init_completion(&set->quiesce_completion); > + > + list_for_each_entry(q, &set->tag_list, tag_set_list) > + blk_mq_quiesce_blocking_queue_async(q); > + wait_for_completion(&set->quiesce_completion); > + } else { > + list_for_each_entry(q, &set->tag_list, tag_set_list) > + blk_mq_quiesce_queue_nowait(q); > + synchronize_rcu(); > + } > + mutex_unlock(&set->tag_list_lock); It would be great to do the wait_for_completion and synchronize_rcu outside the lock. Also I think the blocking case probably wants to be split into a separate little helper. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme