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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1378C6FA8B for ; Thu, 22 Sep 2022 06:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=XkufidiM4E8AW79WmG+yUVbbnK8Hjd8wG2FuMFk9k9Y=; b=KF7nV19AUhKY3upQD54KOnCPNV lY0eGA/4D9q47XM0f0xtUOpCTv24V7qM4PK4M0n71cnC3WhxmMDWt5Zb5QbYQWG/fTTYF8MjWxXrT vZniE5vg1aZbiwI4DtyO67Gwzh2OSg2eEi0VrJX4Wr/gpb8r2ZYl4t0PZrgc/kGJGnOw8EA1B4rza al3eLOgrVwpZTGOgI1rsCup383yV3x87LrDBUZrlMP8CdRR94R31J/qepeBmvjxWoPDaQZ9LrSK65 y39mo08N2LjfENQTeMFVFzUVuHUCrF53f+8F0rmo16Jo5IBjeLLKQC6XW1hVQCkCmLYhyCuBz1O3Z fDFq5WGg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1obFZI-00DX7T-UQ; Thu, 22 Sep 2022 06:20:16 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1obFZG-00DX6b-F5 for linux-nvme@lists.infradead.org; Thu, 22 Sep 2022 06:20:15 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6262168BEB; Thu, 22 Sep 2022 08:20:10 +0200 (CEST) Date: Thu, 22 Sep 2022 08:20:10 +0200 From: Christoph Hellwig To: Liu Song Cc: axboe@kernel.dk, hch@lst.de, kbusch@kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, sagi@grimberg.me Subject: Re: [RFC PATCH] blk-mq: hctx has only one ctx mapping is no need to redirect the completion Message-ID: <20220922062010.GA27946@lst.de> References: <894e18a4-4504-df48-6429-a04c222ca064@kernel.dk> <1663731123-81536-1-git-send-email-liusong@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1663731123-81536-1-git-send-email-liusong@linux.alibaba.com> 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-20220921_232014_670140_4FD31E4B X-CRM114-Status: GOOD ( 13.91 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Sep 21, 2022 at 11:32:03AM +0800, Liu Song wrote: > From: Liu Song > > High-performance NVMe devices usually support a large hw queue, which a larger number of? > /* > - * For a polled request, always complete locally, it's pointless > - * to redirect the completion. > + * For request which hctx has only one ctx mapping, > + * or a polled request, always complete locally, > + * it's pointless to redirect the completion. > */ > - if (rq->cmd_flags & REQ_POLLED) > + if (rq->mq_hctx->nr_ctx == 1 || > + rq->cmd_flags & REQ_POLLED) Some very odd comment formatting and and indentation here.