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 78389C433EF for ; Thu, 18 Nov 2021 08:29:47 +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 46481611C5 for ; Thu, 18 Nov 2021 08:29:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 46481611C5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:In-Reply-To: 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=rCLQQuEeZkbftRFn3kR0ZgS+cL9uIv0W8JgXgekwkI0=; b=gfsPIsJBLF6tcxPwXLNymRTDUr PcoSex2MnWwGPAXf2SErsX4WyRF+TdxIW3LclEKR74DQpGVPj6JOCwlxgE/3dHi3yV9Lp1eeo4oc7 5DFbDjFKGn4jXjXzJnItpvfjyrKCcbQR3AXUi+7tUfC41aQciZ0wZfAGHZmZBIHvwvnDE32RwAiq1 URA2vdHDVi1aJJap4ZlUxdA8cwwOx1Vh5SXgHSKiALWl8KYszXhCSLpx0hhnHOvEolMbRfBIGnrUo rVtlSqi6tyh+/sCfIFg7o0o1i/Kk98EXPY1fz6G63M/ksoMKO6SO8byvLENHGMmtPc8uKW5EOtl1P SndwZp+A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mncng-007CQK-M5; Thu, 18 Nov 2021 08:29:44 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mncnd-007CPV-KY for linux-nvme@lists.infradead.org; Thu, 18 Nov 2021 08:29:43 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637224179; 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=rCLQQuEeZkbftRFn3kR0ZgS+cL9uIv0W8JgXgekwkI0=; b=N9skeedkU+KfBsCoydp2UDlHVuqYMe0gFyeEUaQdT6rqa0YmJN1Ac5Cmjd/UkgWQYxVbVv zhoQo9TUfJliUh2XxGdlFWJGe0+NKETRZ05oFEU+DCSK/XH5YQuqN4QhDJe0A+qvZhV4bV 4ldGl0/CVOUJzpE/BR/Z6JVQCzrJwsA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-271-vAYGcVNIPbunw06HcK2yhA-1; Thu, 18 Nov 2021 03:29:33 -0500 X-MC-Unique: vAYGcVNIPbunw06HcK2yhA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A31F7804140; Thu, 18 Nov 2021 08:29:32 +0000 (UTC) Received: from raketa (unknown [10.40.192.80]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 18EF45D9DE; Thu, 18 Nov 2021 08:29:30 +0000 (UTC) Date: Thu, 18 Nov 2021 09:29:28 +0100 From: Maurizio Lombardi To: Chaitanya Kulkarni Cc: "linux-nvme@lists.infradead.org" , "sagi@grimberg.me" , "hch@lst.de" Subject: Re: [PATCH RFC] nvmet: fix tmpfs-based backstores support Message-ID: <20211118082928.GA82729@raketa> References: <20211117152454.122014-1-mlombard@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mlombard@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211118_002941_771886_28AEF6FE X-CRM114-Status: GOOD ( 13.55 ) 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 Thu, Nov 18, 2021 at 01:59:29AM +0000, Chaitanya Kulkarni wrote: > We will need blktests for this. > > Also, can you share performance numbers with this patch and > the errors that you are getting without this patch ? Ok, I will try to run blktests and provide some performance numbers. Without this patch, writes get lost: [root@kvm-02-guest03 ~]# nvme connect -t tcp -a 10.37.153.75 -n test-nqn -s 4080 [root@kvm-02-guest03 ~]# dd if=/dev/urandom of=/dev/nvme0n1 bs=1M count=1 1+0 records in 1+0 records out 1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0604551 s, 17.3 MB/s [root@kvm-02-guest03 ~]# hexdump -C /dev/nvme0n1 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 06400000 dmesg output: [81489.687548] blk_update_request: critical target error, dev nvme0c0n1, sector 0 op 0x1:(WRITE) flags 0x2000800 phys_seg 256 prio class 0 [81489.691139] buffer_io_error: 246 callbacks suppressed [81489.691141] Buffer I/O error on dev nvme0n1, logical block 0, lost async page write [81489.695013] Buffer I/O error on dev nvme0n1, logical block 1, lost async page write [81489.697183] Buffer I/O error on dev nvme0n1, logical block 2, lost async page write [81489.699239] Buffer I/O error on dev nvme0n1, logical block 3, lost async page write [81489.701297] Buffer I/O error on dev nvme0n1, logical block 4, lost async page write [81489.703374] Buffer I/O error on dev nvme0n1, logical block 5, lost async page write [81489.705459] Buffer I/O error on dev nvme0n1, logical block 6, lost async page write [81489.707511] Buffer I/O error on dev nvme0n1, logical block 7, lost async page write [81489.709438] Buffer I/O error on dev nvme0n1, logical block 8, lost async page write [81489.711364] Buffer I/O error on dev nvme0n1, logical block 9, lost async page write Maurizio