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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 7F79AD6ED09 for ; Thu, 21 Nov 2024 11:31:16 +0000 (UTC) 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:In-Reply-To:Content-Type: 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=09vF4pX8kaQ+dR6O2t20RwvdrQl+POuIrCNnkaiSmgA=; b=guegO3Ty2n6tVfDBIZNBN7wgTO Bc6vfoCQfevkStOrEHWGeTCM6/FFj9XIOFIKPKrYPnogKOeIRbC21/k45Eg6yQ6lzpZ9F+DB4fzx+ bTVVBCh5dC5cnYaOMIEqJZbTCeo3wUO6YxxQm3nBNysCvWsR/TtCAb/Ime0SFxBLXg3WyzGSj1YRh 3mhM0zeRk/Kev8DlUDGRQn9ChNWADiYIzC/hCXdB6NZXbT6NDPOL/JYxT3ag6VPBGqYEpRxJZLmVJ lBv6FmYR+66LPm0t/17VuM9U95R8Ba6kmUcgjnhz/H6SZeXEtG7vm9TNyjYy7kIZ5gXv5Fc/6uU5j 8OshHrYQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tE5Oz-0000000HU8M-1Fvd; Thu, 21 Nov 2024 11:31:13 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tE5Ov-0000000HU6D-1YwD for linux-nvme@lists.infradead.org; Thu, 21 Nov 2024 11:31:11 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1732188666; 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=09vF4pX8kaQ+dR6O2t20RwvdrQl+POuIrCNnkaiSmgA=; b=Ay76XVSCjUAfFZmUQr1F4Ch/gUzCrDBcgGHawtUbhFxiLw6xB4Fsi48fYmbDcF/63l5j3a l5sW5BJo4VHdSc1bip+DheqlhuIVzDIR6k0IePiWlBlBwJQ/cHoJdciBufBEuY/FpNbtN7 ppwCXNcYVLzZQkyuUwe9FB/ouhvhZP0= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-335-VkpqpWfkOBifU72Bt2MalA-1; Thu, 21 Nov 2024 06:31:05 -0500 X-MC-Unique: VkpqpWfkOBifU72Bt2MalA-1 X-Mimecast-MFC-AGG-ID: VkpqpWfkOBifU72Bt2MalA Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 646091955D62; Thu, 21 Nov 2024 11:31:03 +0000 (UTC) Received: from pauld.westford.csb (unknown [10.22.80.137]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 07F81195607C; Thu, 21 Nov 2024 11:31:00 +0000 (UTC) Date: Thu, 21 Nov 2024 06:30:58 -0500 From: Phil Auld To: Jens Axboe Cc: Chaitanya Kulkarni , Saeed Mirzamohammadi , "linux-kernel@vger.kernel.org" , "linux-nvme@lists.infradead.org" , Ramanan Govindarajan , Sagi Grimberg , Paul Webb , Christoph Hellwig , Keith Busch Subject: Re: [bug-report] 5-9% FIO randomwrite ext4 perf regression on 6.12.y kernel Message-ID: <20241121113058.GA394828@pauld.westford.csb> References: <392209D9-5AC6-4FDE-8D84-FB8A82AD9AEF@oracle.com> <0cfbfcf6-08f5-4d1b-82c4-729db9198896@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241121_033109_482718_60A4CB53 X-CRM114-Status: GOOD ( 30.89 ) 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 Hi, On Wed, Nov 20, 2024 at 06:20:12PM -0700 Jens Axboe wrote: > On 11/20/24 5:00 PM, Chaitanya Kulkarni wrote: > > On 11/20/24 13:35, Saeed Mirzamohammadi wrote: > >> Hi, > >> > >> I?m reporting a performance regression of up to 9-10% with FIO randomwrite benchmark on ext4 comparing 6.12.0-rc2 kernel and v5.15.161. Also, standard deviation after this change grows up to 5-6%. > >> > >> Bisect root cause commit > >> =================== > >> - commit 63dfa1004322 ("nvme: move NVME_QUIRK_DEALLOCATE_ZEROES out of nvme_config_discard?) > >> > >> > >> Test details > >> ========= > >> - readwrite=randwrite bs=4k size=1G ioengine=libaio iodepth=16 direct=1 time_based=1 ramp_time=180 runtime=1800 randrepeat=1 gtod_reduce=1 > >> - Test is on ext4 filesystem > >> - System has 4 NVMe disks > >> > > > > Thanks a lot for the report, to narrow down this problem can you > > please :- > > > > 1. Run the same test on the raw nvme device /dev/nvme0n1 that you > > have used for this benchmark ? > > 2. Run the same test on the XFS formatted nvme device instead of ext4 ? > > > > This way we will know if there is an issue only with the ext4 or > > with other file systems are suffering from this problem too or > > it is below the file system layer such as block layer and nvme pci driver ? > > > > It will also help if you can repeat these numbers for io_uring fio io_engine > > to narrow down this problem to know if the issue is ioengine specific. > > > > Looking at the commit [1], it only sets the max value to write zeroes > > sectors > > if NVME_QUIRK_DEALLOCATE_ZEROES is set, else uses the controller max > > write zeroes value. > > There's no way that commit is involved, the test as quoted doesn't even > touch write zeroes. Hence if there really is a regression here, then > it's either not easily bisectable, some error was injected while > bisecting, or the test itself is bimodal. I was just going to ask how confident we are in that bisect result. I suspect this is the same issue I've been fighting here: https://lore.kernel.org/lkml/20241101124715.GA689589@pauld.westford.csb/ Saeed, can you try your randwrite test after "echo NO_DELAY_DEQUEUE > /sys/kernel/debug/sched/features" please? We don't as yet have a general fix for it as it seems to be a bit of a trade off. Cheers, Phil > > -- > Jens Axboe > --