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, NICE_REPLY_A,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 4EB20C433DF for ; Tue, 11 Aug 2020 03:13:41 +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 1BF71206C3 for ; Tue, 11 Aug 2020 03:13:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="qdjMpGC1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BF71206C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com 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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=kM0JI6t1buL4E6JcPlufApF2oepCdQmaFNmi+xnAvaI=; b=qdjMpGC1ZV6cIMoaCuNmKdmBP OUmIdaqKO0Az89/MmRsS3jjS0X9z3augpaPv6mK9QuWXZwCY+ILlQCQoyFtsCowjUnckdEeNhe5wH /dT2Jkh/H4bzjYGeIb1l4vtKQ7NAnzHD8rj5Fc8wirkSMUuAvF/M2zQC9PCwDyR5qTOKnB/x81UpA fRHdCNrX7wD1XWbKg3S6fD5Mix20xJfjYBj0HvylXfmwDAXlj0/g5Mc2DdCdFxZ+oCkrhOsTKoDJQ vu4jM2qVOuU7MbPOF9sAEfiQ88Jf2uMM0i2p4LkaGLtM0SgL+7DKidB+AQMxZJdpZVqnSEM17amPl 91+iCHqmA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k5KjF-0004dY-QO; Tue, 11 Aug 2020 03:13:33 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k5KjA-0004cG-KP for linux-nvme@lists.infradead.org; Tue, 11 Aug 2020 03:13:29 +0000 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 7E13A863C7704E13A4B4; Tue, 11 Aug 2020 11:13:20 +0800 (CST) Received: from [10.169.42.93] (10.169.42.93) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.487.0; Tue, 11 Aug 2020 11:13:14 +0800 Subject: Re: [PATCH v2 0/3] reduce quiesce time for lots of name spaces To: Ming Lei References: <20200807090559.29582-1-lengchao@huawei.com> <20200807134932.GA2122627@T590> <61a78a78-73aa-1c67-1e8c-eae8f7c3a4e0@huawei.com> <20200810031547.GB2202641@T590> From: Chao Leng Message-ID: <6dc6bb01-5bfd-bf13-f53a-1bc75a6b3991@huawei.com> Date: Tue, 11 Aug 2020 11:13:14 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200810031547.GB2202641@T590> Content-Language: en-US X-Originating-IP: [10.169.42.93] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200810_231328_972371_1AFCB1EE X-CRM114-Status: UNSURE ( 7.10 ) X-CRM114-Notice: Please train this message. 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: axboe@fb.com, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, kbusch@kernel.org, hch@lst.de Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 2020/8/10 11:15, Ming Lei wrote: >> About using per_cpu to replace SRCU, I suggest separate discussion. >> Can you show the patch? This will make it easier to discuss. > https://lore.kernel.org/linux-block/20200728134938.1505467-1-ming.lei@redhat.com/ Directly replace SRCU with percpu_ref, is not safe. This may make quiesce queue wait extra time, in extreme scenario, maybe wait for ever. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme