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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C621C433EF for ; Tue, 12 Oct 2021 15:07:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40D066052B for ; Tue, 12 Oct 2021 15:07:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237352AbhJLPJK (ORCPT ); Tue, 12 Oct 2021 11:09:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:28493 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237062AbhJLPJJ (ORCPT ); Tue, 12 Oct 2021 11:09:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634051227; 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=jXSeKkVlYOYMFbXldE+ZY1oBqyx/jHfPT9bwC8eSB9I=; b=GnkxLJCLlKkFPd4hnCTJzmYQrQ0Mlimn71OFaj0+vDL+k9txag/Io7+7MhMooJTnSqdmxw /L0rbtcn3cXV4mdigx3RGkv8aG+SrZFNPvlzZpr/FL3WzOekm8/oFvt88H9gCIhkNEob5G du5oDRCFv/2Pck3d8pPz4Y0znNCgrmc= 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-214-SY_I9Pu1M9WRGHWECdziKg-1; Tue, 12 Oct 2021 11:07:02 -0400 X-MC-Unique: SY_I9Pu1M9WRGHWECdziKg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C29BA19067E4; Tue, 12 Oct 2021 15:07:00 +0000 (UTC) Received: from T590 (ovpn-8-34.pek2.redhat.com [10.72.8.34]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4248F5D6A8; Tue, 12 Oct 2021 15:06:55 +0000 (UTC) Date: Tue, 12 Oct 2021 23:06:51 +0800 From: Ming Lei To: Christoph Hellwig Cc: Jens Axboe , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, Chaitanya Kulkarni , Sagi Grimberg , Keith Busch , Bart Van Assche Subject: Re: [PATCH V3 6/6] blk-mq: support concurrent queue quiesce/unquiesce Message-ID: References: <20211009034713.1489183-1-ming.lei@redhat.com> <20211009034713.1489183-7-ming.lei@redhat.com> <20211012103010.GA29640@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211012103010.GA29640@lst.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Oct 12, 2021 at 12:30:10PM +0200, Christoph Hellwig wrote: > On Sat, Oct 09, 2021 at 11:47:13AM +0800, Ming Lei wrote: > > + spin_lock_irqsave(&q->queue_lock, flags); > > + if (!q->quiesce_depth++) > > + blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q); > > We can get rid of the QUEUE_FLAG_QUIESCED flag now and just look > at ->quiesce_depth directly. I'd rather not to do that given we need to check QUEUE_FLAG_QUIESCED in fast path. > > > + spin_lock_irqsave(&q->queue_lock, flags); > > + WARN_ON_ONCE(q->quiesce_depth <= 0); > > + if (q->quiesce_depth > 0 && !--q->quiesce_depth) { > > if (WARN_ON_ONCE(q->quiesce_depth <= 0)) > ; /* oops */ > else if (!--q->quiesce_depth) > run_queue = true; OK. Thanks, Ming