From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6094833DF for ; Tue, 15 Apr 2025 02:05:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744682738; cv=none; b=qxKSkBaxYaqFUvrD3pT78ks3Xn6wtr4xVwUeAoo3j3Aj5ZoA4P6sMt6En/kl/P/ICIYTgVVQUuPr/lTAAc4VvSAqH8LlavLM3OlplZAE0vM8iiUwq0IUNzoSmM37y8sfLozgPeArzjcfOdL9OjvRiUEB82mr6djbaywjUSF3WI4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744682738; c=relaxed/simple; bh=kMjAo71Sn0fyCc9X4XMEeo3L9tp+WLVeQenG/kvkplU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CZRrR5KHxOOUKN/e1Pz77/AM0XOMGz5BIWD9DEgCWRADTAfGH36gZsfwaSzsdVUK8KnrynNsItcwolMHbipi7TxrWGflLD+LJrR0oqWmZBfD/sFfDpiVkwa4UMMYF+S20PFngnx7MoohRGd30oI2rlV0IGHOdaHhlLO0/vSPsLQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=JiVVAdsC; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JiVVAdsC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744682735; 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=qAbl51vBbU9TsoQAQrWTusQOKiOqUp740Q7mupXqAao=; b=JiVVAdsCUcqEW/Fj7Z0PsDe/+yN6oth2rzaQgeacHtAr+Xx+1ptPTZfJpGj2D0qagJC5vA fA812+hM6YWm2qpTiIob3PIvhmUv1tAZsaj3Vrjs12Dg3A6iIL8CFHXjZ3+l9/HnhOCDKX D1e/PCDsa7RatzJ50W3hVrCuA5yP6p4= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-31-YGziZXAPM46RjAXEsB4QMw-1; Mon, 14 Apr 2025 22:05:31 -0400 X-MC-Unique: YGziZXAPM46RjAXEsB4QMw-1 X-Mimecast-MFC-AGG-ID: YGziZXAPM46RjAXEsB4QMw_1744682729 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7E36E180035E; Tue, 15 Apr 2025 02:05:29 +0000 (UTC) Received: from fedora (unknown [10.72.116.40]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7AA27180B488; Tue, 15 Apr 2025 02:05:24 +0000 (UTC) Date: Tue, 15 Apr 2025 10:05:16 +0800 From: Ming Lei To: Christoph Hellwig Cc: Jens Axboe , linux-block@vger.kernel.org, Nilay Shroff , Shinichiro Kawasaki , Thomas =?iso-8859-1?Q?Hellstr=F6m?= Subject: Re: [PATCH 05/15] block: simplify elevator reset for updating nr_hw_queues Message-ID: References: <20250410133029.2487054-1-ming.lei@redhat.com> <20250410133029.2487054-6-ming.lei@redhat.com> <20250410153417.GA12430@lst.de> <20250414060959.GB6451@lst.de> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250414060959.GB6451@lst.de> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On Mon, Apr 14, 2025 at 08:09:59AM +0200, Christoph Hellwig wrote: > On Mon, Apr 14, 2025 at 08:58:28AM +0800, Ming Lei wrote: > > > Coming back to this after looking through the next patches. > > > > > > Why do we even need the __elevator_change call here? We've not > > > actually disabled the elevator, and we prevent other callers > > > from changing it. > > > > > > As you pass in the force argument this now always calls > > > elevator_switch and thus blk_mq_init_sched. But why? > > > > sched tags is built over hctx and depends on ->nr_hw_queues, > > when nr_hw_queues is changed, sched tags has to be rebuilt. > > Can you add a comment explaining this? Sure. Thanks, Ming