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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 3F3C9C3A5A7 for ; Tue, 3 Sep 2019 16:08:53 +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 1434B208E4 for ; Tue, 3 Sep 2019 16:08:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="qeqhsONX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1434B208E4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=deltatee.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Subject:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=DeRRIUCwZpjmVfrCXs3xldJCEKPctGP/95pDDDxu2C4=; b=qeqhsONXwkamhU Y/RRJ9I0dTN8ZK7xt/v8pouveS3pdP845VsaJtUK2RRbfH6Ne2zFA3PaRwZNKy2G7CP3D4laLmvg3 a7Zoks9PwaKbPmpfc3A4N0Yf6dcRV8QwzU1kF7cX5Ihf2Y6dZLIiNCI/doms1RsNvBkCh16PRgFLk TXQXHVit2Kd0p7flSXuDWRy14RZuefltz05j6LJoyd56ttK7xHOEeGbpNFZNkOrRQokD2EITc/PKD sF7DWVZ5tY+fpBaUvSjJF/umtVjUP+h6qNo3elQUNc2/Ax94KwHODuQdjGy5tlBTz1nekzWQVTS2v hubsB7/uDcqGujJPnACw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i5BML-0002V4-1s; Tue, 03 Sep 2019 16:08:45 +0000 Received: from ale.deltatee.com ([207.54.116.67]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i5BMH-0002UJ-II for linux-nvme@lists.infradead.org; Tue, 03 Sep 2019 16:08:43 +0000 Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtp (Exim 4.89) (envelope-from ) id 1i5BLi-0007Ci-LT; Tue, 03 Sep 2019 10:08:08 -0600 To: Keith Busch References: <20190831000139.7662-1-logang@deltatee.com> <20190831152910.GA29439@localhost.localdomain> From: Logan Gunthorpe Message-ID: <33af4d94-9f6d-9baa-01fa-0f75ccee263e@deltatee.com> Date: Tue, 3 Sep 2019 10:08:01 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190831152910.GA29439@localhost.localdomain> Content-Language: en-CA X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: martin.petersen@oracle.com, hare@suse.com, kbusch@kernel.org, axboe@fb.com, sagi@grimberg.me, hch@lst.de, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, keith.busch@intel.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [PATCH] nvme-core: Fix subsystem instance mismatches X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190903_090842_011567_3700B5C3 X-CRM114-Status: GOOD ( 10.55 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Hannes Reinecke , Sagi Grimberg , "Martin K . Petersen" , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Jens Axboe , Keith Busch , Christoph Hellwig 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 2019-08-31 9:29 a.m., Keith Busch wrote: > On Fri, Aug 30, 2019 at 06:01:39PM -0600, Logan Gunthorpe wrote: >> To fix this, assign the subsystem's instance based on the instance >> number of the controller's instance that first created it. There should >> always be fewer subsystems than controllers so the should not be a need >> to create extra subsystems that overlap existing controllers. > > The subsystem's lifetime is not tied to the controller's. When the > controller is removed and releases its instance, the next controller > to take that available instance will create naming collisions with the > subsystem still using it. > Hmm, yes, ok. So perhaps we can just make the subsystem prefer the ctrl's instance when allocating the ID? Then at least, in the common case, the controller numbers will match the subsystem numbers. Only when there's random hot-plugs would the numbers get out of sync. Logan _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme