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 3D237C53200 for ; Wed, 29 Jul 2026 08:35:21 +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:References:Content-Type: Content-Transfer-Encoding:MIME-Version:In-Reply-To:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=nMumBf6pcwJN35QNg21EPnkz/AZt8LVlK2YGNnvhzR0=; b=opIf8INXm2yLjNNrQePNTv2uYh 6LBaVjF1K/5AyvCjBoL4PJFnUxl/T5m2LxlXWJP7Z+MylZyFDCGl2pGtird9cFGa1H8wFNvq7EdOV MWOamNAVpvpJH53W1tmqECaU0ApX2Aojg1SQZQIfiYY77OnSRNcER1Nty/lo5+vkx5xwVXEHIQbtQ oXxne+wVk1HkKGFmAFdkEwG/AQ6CAHOpvu/6MKmZ4WcyV9krcLvqUZ6dp5b7IHEz/rTP9/tPpX/x3 KpnBMKiw9y3m+2p8dF5NLGjKAGH8NAcW57DkGhGvisYPXA/Zv+dv+vkOXkBkzS1gEGCv0LuP5Ktp4 4+d3XPOQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wozl0-00000007FEv-1yhP; Wed, 29 Jul 2026 08:35:18 +0000 Received: from mailout4.samsung.com ([203.254.224.34]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wozkv-00000007FB8-1EFl for linux-nvme@lists.infradead.org; Wed, 29 Jul 2026 08:35:17 +0000 Received: from epcas5p4.samsung.com (unknown [182.195.41.42]) by mailout4.samsung.com (KnoxPortal) with ESMTP id 20260729083503epoutp0464ea8448ebefe006dbac0040965bf576~GtbfPB_x80385403854epoutp04c for ; Wed, 29 Jul 2026 08:35:03 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20260729083503epoutp0464ea8448ebefe006dbac0040965bf576~GtbfPB_x80385403854epoutp04c DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1785314103; bh=nMumBf6pcwJN35QNg21EPnkz/AZt8LVlK2YGNnvhzR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=saiJoAhy/r7KRwVHHR7YIjl+Nj7jXx0336/L9WpCTejiCSFqRiZqSbxMvaUbv8NU+ kkSUaNQ8zh8zuU9bBheB7sAGTwYiYPlFaARqwxR9n2aNYqgqXqjBwiJx3DUq/t9TEv QBtUstpUNwLJo7RQ4CaoQbXAPVsNOYFEScxUaHCY= Received: from epsnrtp01.localdomain (unknown [182.195.42.153]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPS id 20260729083502epcas5p2956791f6317ffa4deaefdfb2eaa3c15c~Gtbeng5sa2833528335epcas5p2F; Wed, 29 Jul 2026 08:35:02 +0000 (GMT) Received: from epcpadp1new (unknown [182.195.40.141]) by epsnrtp01.localdomain (Postfix) with ESMTP id 4h95HV4cXxz6B9m7; Wed, 29 Jul 2026 08:35:02 +0000 (GMT) Received: from epsmtip1.samsung.com (unknown [182.195.34.30]) by epcas5p4.samsung.com (KnoxPortal) with ESMTPA id 20260728145333epcas5p427c6b6d72bff02de3f29e6a6a2108958~Ge8rj7-9K0791907919epcas5p40; Tue, 28 Jul 2026 14:53:33 +0000 (GMT) Received: from green245.samsungds.net (unknown [107.99.41.245]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20260728145330epsmtip1f20094ebf53bcd1bb08fe2dba866c798~Ge8oxGFnu0743207432epsmtip1b; Tue, 28 Jul 2026 14:53:30 +0000 (GMT) From: Alok Rathore To: wangyang.guo@intel.com Cc: akpm@linux-foundation.org, axboe@fb.com, dan.liang@intel.com, hch@lst.de, kbusch@kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, ming.lei@redhat.com, rrendec@redhat.com, sagi@grimberg.me, tglx@linutronix.de, tianyou.li@intel.com, tim.c.chen@linux.intel.com, virtualization@lists.linux-foundation.org, asml.silence@gmail.com, cpgs@samsung.com, gost.dev@samsung.com, alokrathore20@gmail.com, nitheshshetty@gmail.com, Alok Rathore Subject: Re: [PATCH v2] lib/group_cpus: make group CPU cluster aware Date: Tue, 28 Jul 2026 20:23:03 +0530 Message-Id: <561480862.11785314102640.JavaMail.epsvc@epcpadp1new> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20260113022958.3379650-1-wangyang.guo@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CMS-MailID: 20260728145333epcas5p427c6b6d72bff02de3f29e6a6a2108958 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 105P X-CPGSPASS: Y X-Hop-Count: 3 X-CMS-RootMailID: 20260728145333epcas5p427c6b6d72bff02de3f29e6a6a2108958 References: <20260113022958.3379650-1-wangyang.guo@intel.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260729_013514_798402_01E74143 X-CRM114-Status: UNSURE ( 8.25 ) X-CRM114-Notice: Please train this message. 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 For higher number of jobs(>=64), we are seeing ~8% regression with this patch. Tool: fio with io_uring engine [1] +------------+------------+-------------------+ | numjobs | before | after patch | +------------+------------+-------------------+ | 1 | 89 | 88.8 (-0.22%) | | 2 | 169 | 168 (-0.59%) | | 4 | 338 | 337 (-0.30%) | | 8 | 533 | 533 (0.00%) | | 16 | 538 | 541 (+0.56%) | | 32 | 685 | 716 (+4.53%) | | 64 | 933 | 859 (-7.93%) | | 128 | 941 | 867 (-7.86%) | +------------+------------+-------------------+ * Metric: IOPS (K) (Block device, QD = 1, bs = 4K, Random Read) As shown in the table above, while performance is comparable at low job counts, there is a drop starting from 64 jobs after this patch. HW info: Intel(R) Core(TM) Ultra 7 265K CPU=20 IRQ-CPU are 1:1 mapped. [1] fio -filename=/dev/nvme0n1 -direct=1 -size=4g -rw=randread \ -numjobs=$(numjobs) -bs=4096 -ioengine=io_uring -iodepth=1 \ -name=uring_test --registerfiles=1 --ramp_time=5 \ --group_reporting --thread