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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 05641C433F5 for ; Tue, 7 Sep 2021 23:04:38 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 9401A60E52 for ; Tue, 7 Sep 2021 23:04:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9401A60E52 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 5657D402B9; Tue, 7 Sep 2021 23:04:37 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ufHn3Gfo-Jmk; Tue, 7 Sep 2021 23:04:36 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp2.osuosl.org (Postfix) with ESMTPS id C191B40104; Tue, 7 Sep 2021 23:04:35 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9BCC3C0011; Tue, 7 Sep 2021 23:04:35 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 0BC77C000D for ; Tue, 7 Sep 2021 23:04:35 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id E1D7640410 for ; Tue, 7 Sep 2021 23:04:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp4.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=kernel.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eZvwhm2TVGfq for ; Tue, 7 Sep 2021 23:04:34 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp4.osuosl.org (Postfix) with ESMTPS id 6F06440401 for ; Tue, 7 Sep 2021 23:04:34 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 365DD61102; Tue, 7 Sep 2021 23:04:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631055873; bh=U4r90XGeMFMBTYQzJqJqJ72n/aEzus0q4Z98AOX2grc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sKXNN3dc3jccHx69/sKD47gbQLIRPr5FvdMGBsnJ/eUfbMNTLqUqNfWSvns+I69ck U25GKT7tGRJbAWVj0zvnCcxOB6w4HzBT1Fe6R/PlLWnsRJcpQuvxrlr71Ab0Gl0r/g yCUbkzUr9DQXvBlG7STLjsnFeql70rUCYRhVNXo5P9Gd5NRMXopOXF68LZg0JtLbDj NWDsTld22BYYdo8O+Vk07IJEW02ZwlwcdChvtN2kzeHNXcIDL0mt9ZFToQ/iPeAFMS FGhfCRqW9/t3Jn7umP3x8hpJMQ+gNd+0TD6+cH0YIKQMIROMhf40SlprUdwNv8QkXz HpLc51HwA2u3Q== Date: Wed, 8 Sep 2021 02:04:30 +0300 From: Leon Romanovsky To: "Michael S. Tsirkin" Subject: Re: [PATCH v3 1/1] virtio-blk: add num_request_queues module parameter Message-ID: References: <20210902204622.54354-1-mgurtovoy@nvidia.com> <20210905111415-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210905111415-mutt-send-email-mst@kernel.org> Cc: Max Gurtovoy , linux-block@vger.kernel.org, kvm@vger.kernel.org, israelr@nvidia.com, nitzanc@nvidia.com, virtualization@lists.linux-foundation.org, hch@infradead.org, Chaitanya Kulkarni , axboe@kernel.dk, stefanha@redhat.com, oren@nvidia.com X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" On Sun, Sep 05, 2021 at 11:15:16AM -0400, Michael S. Tsirkin wrote: > On Sun, Sep 05, 2021 at 01:20:24PM +0300, Leon Romanovsky wrote: > > On Sun, Sep 05, 2021 at 01:49:46AM -0700, Chaitanya Kulkarni wrote: > > > > > > On 9/5/2021 12:46 AM, Leon Romanovsky wrote: > > > > > +static unsigned int num_request_queues; > > > > > +module_param_cb(num_request_queues, &queue_count_ops, &num_request_queues, > > > > > + 0644); > > > > > +MODULE_PARM_DESC(num_request_queues, > > > > > + "Number of request queues to use for blk device. Should > 0"); > > > > > + > > > > Won't it limit all virtio block devices to the same limit? > > > > > > > > It is very common to see multiple virtio-blk devices on the same system > > > > and they probably need different limits. > > > > > > > > Thanks > > > > > > > > > Without looking into the code, that can be done adding a configfs > > > > > > interface and overriding a global value (module param) when it is set from > > > > > > configfs. > > > > So why should we do double work instead of providing one working > > interface from the beginning? > > > > Thanks > > > > > > > > > > The main way to do it is really from the hypervisor. This one > is a pretty blunt instrument, Max here says it's useful to reduce > memory usage of the driver. If that's the usecase then a global limit > seems sufficient. How memory will you reduce? It is worth to write it in the commit message. Thanks > > -- > MST > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization