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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 68A77C433EF for ; Fri, 17 Sep 2021 13:41:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EA8D60F38 for ; Fri, 17 Sep 2021 13:41:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232849AbhIQNnU (ORCPT ); Fri, 17 Sep 2021 09:43:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:20296 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232579AbhIQNnT (ORCPT ); Fri, 17 Sep 2021 09:43:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631886115; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=qPKKKwH2jQdgPx6wq21W8Af/fgq6lGJhjobpr3nUL5w=; b=ffcT7K/hO9LyVTTwwp4lP+nhae7e1C+vVx/t0Jv5bnC2VOwBoIGv4YaJCOU51Yde8T36qp 9CppBcU/8NUNV7mAnOKsOeSdNgrX3nFCfIg5wYia8inrambSXzuFWiUDYnQjmx0rNH8965 m3DsAgShbNZpRwn7PMFSOp39x9/pxno= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-47-3drzJqFtNCmlyFNSItDhQw-1; Fri, 17 Sep 2021 09:41:54 -0400 X-MC-Unique: 3drzJqFtNCmlyFNSItDhQw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 453631054F90; Fri, 17 Sep 2021 13:41:53 +0000 (UTC) Received: from T590 (ovpn-12-131.pek2.redhat.com [10.72.12.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2B3635D9C6; Fri, 17 Sep 2021 13:41:36 +0000 (UTC) Date: Fri, 17 Sep 2021 21:41:49 +0800 From: Ming Lei To: Christoph Hellwig Cc: Jens Axboe , linux-block@vger.kernel.org, "Martin K . Petersen" , linux-scsi@vger.kernel.org, Sven Schnelle Subject: Re: [PATCH] scsi: core: cleanup request queue before releasing gendisk Message-ID: References: <20210916101451.GA26782@lst.de> <20210916142009.GA12603@lst.de> <20210917065305.GA24012@lst.de> <20210917075650.GA28455@lst.de> <20210917123719.GA17003@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210917123719.GA17003@lst.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Sep 17, 2021 at 02:37:19PM +0200, Christoph Hellwig wrote: > On Fri, Sep 17, 2021 at 04:32:15PM +0800, Ming Lei wrote: > > > Is it? For the typical case the second free in blk_cleanp_queue will > > > be bsically free because there is no pending I/O. The only case > > > where that matters if if there is pending passthrough I/O again, > > > which can only happen with SCSI, and even there is highly unusual. > > > > RCU grace period is involved in blk_freeze_queue(). > > where? __percpu_ref_switch_to_atomic(). -- Ming