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 1D7C5C433F5 for ; Wed, 29 Sep 2021 01:36:20 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C8F11613A9 for ; Wed, 29 Sep 2021 01:36:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C8F11613A9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=POz/zP0D2PljP4wozLKC0rOOB6eXRtnWIQN80oojYnI=; b=Pibc8RVuQT2Z+D 33+hEpLUtFxburqYk1cHJmZd/T32RerNFmkR80Tqon7yxE8QMNwr9jij5kwcXOdHipXu6EzXzwLiD +/Imgt0oeCZ/9Jscy+/TBvdIDgcrCruPR4+Afqevm/LYKsv9mlAwx4Is2ZfxSrMAwLIeOPZ85pG9v 8SKXZgRJgxpy7oWmxaATmjY1a+FpBOSeeAYIN9DCf6VkvY1guKrpv1txMT3TPJCU0BKpLbBZ75qwb 1Z0tCFJh0UtmTJL1OJ4vaKuvCIBX0GgA8/gsfeCXH2950WP7kS7VFRAw1va4sj/gfU1S48kovtgY1 dWWEYMcf3hzM/5hiljJQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mVOVs-009YlG-M0; Wed, 29 Sep 2021 01:36:00 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mVOVq-009Ykn-5T for linux-nvme@lists.infradead.org; Wed, 29 Sep 2021 01:35:59 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 45B99613C8; Wed, 29 Sep 2021 01:35:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632879357; bh=xSMiKh7QybnDR2qbX+96VqnNYtclBvGgdVuMnAe6HPs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=snEgIBY9KwHbHJZMaGeeE3aPZ4kMKYkw5to0k3mYm6bOmfNaZU6It3CRXmtghMB47 YatMOyOxPwD7RF0L+57kTPJz0kCtXi9ZGR8TZrE/RigfnOpKX143V9kOVtwsW7CZ/H NYPRLCe0LUI9OUwuOWdOsQmAnZOTRGwWSZ0BV78bbQyUKk/RYDYHfT84wjiiBThpTT 7v5sCROQb/6ARL0vDStXZyFNqaPslXEvDqBVtp9iedJlbY89AU0AfPyjW5nzWFb0f5 p1HtfGN8PiJ1tWsmbXi3M1gA3gRkXyLle92oFVx17W/xF5SthfApsqciD2Eb8d3YRK 1t1OYfPpxz2uA== Date: Tue, 28 Sep 2021 18:35:54 -0700 From: Keith Busch To: "Nikitin, Andrey" Cc: Christoph Hellwig , Benjamin Herrenschmidt , "linux-nvme@lists.infradead.org" , "Buches, Dave" Subject: Re: [RFC PATCH 0/3] nvme sq associations Message-ID: <20210929013554.GA405465@dhcp-10-100-145-180.wdc.com> References: <79563B18-671F-4654-AE74-7FD9AB5417EF@amazon.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <79563B18-671F-4654-AE74-7FD9AB5417EF@amazon.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210928_183558_249129_B5174B3A X-CRM114-Status: GOOD ( 14.02 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Sep 29, 2021 at 12:48:49AM +0000, Nikitin, Andrey wrote: > On 9/25/21, 01:38, "Christoph Hellwig" wrote: > > > > Honestly I'd rather not merge this whole patchset at all. It is a > > completly frinde feature for a totally misdesigned part of the NVMe > > spec. Until actual controller in the hands of prosumers support > > anything like that I'm very reluctant to bloat the driver fast path for > > it. > > Thank you for the feedback. > While I agree with your remarks regarding feature design in NVMe spec > the minimal implementation proposed in this patchset would help resolving > the problems outlined int the original post (undesired queue sharing and > noisy neighbor). You still get noisy neighbor with this approach, though: completions from one set can stall the driver from reaping another set's completions that were posted earlier. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme