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 36AE6C2BD09 for ; Mon, 1 Jul 2024 07:21:43 +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=M+g42u0E0RJmKENIvoxoEw3yJCtdKnco3k8DpYO4KE0=; b=SuCj4zOJAXE4u8FKg2BWIp1nP+ wloN9n1NAd9QM6vAN6q8lAFTTc98MUSiGQfX2+MAs3MvBJYp7NwLQzoMHSRPQC7gMsRL+o4nqamO5 HCqlEZScwJy4Z4vBTzbqAOcGj6iMYQLPkljgj8bgLZSLLcHsnF4uxzruPonONtzW7618dw5o/gpiT wUBTyQ+nq5oxSwhsLXlo4Wv64eCL7eBDX9RIia8rjAfa+GzyuN0EtEWhIHrKhvskNFwUGUv3KwdHV lJhvXPxoy3b33i7YlTOWUGw4DIuyOkTuu+5roHpFSbIiEiwqEqok7Tv4SGXU3f2ZH1Z/Mg8W9YKL5 ta+1Bj0w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOBM4-000000020kf-3av2; Mon, 01 Jul 2024 07:21:40 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOBM1-000000020k9-3pXi for linux-nvme@lists.infradead.org; Mon, 01 Jul 2024 07:21:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719818496; 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=M+g42u0E0RJmKENIvoxoEw3yJCtdKnco3k8DpYO4KE0=; b=TNjTi7BxFekd93M/TjrCY2zXFYLf+uufMJpiehKXhVpFsX4NrrYLS+LpnaeCLJKooDHqBO BPVK3/CcxNagO/HA2tUjIwKHaBq5NdCw1+j6LcCxi+H5aGC84/0jD1OnTC/0XdJyp9R8XJ gTpboaKzy0pEI2FvRNXNmp3wPXbV98Y= Received: from mx-prod-mc-02.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-135-6rDNLKIsNk6DoD4JULhg0w-1; Mon, 01 Jul 2024 03:21:30 -0400 X-MC-Unique: 6rDNLKIsNk6DoD4JULhg0w-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C7B1419560B0; Mon, 1 Jul 2024 07:21:27 +0000 (UTC) Received: from fedora (unknown [10.72.112.45]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5D40A3000229; Mon, 1 Jul 2024 07:21:18 +0000 (UTC) Date: Mon, 1 Jul 2024 15:21:13 +0800 From: Ming Lei To: Daniel Wagner Cc: Jens Axboe , Keith Busch , Sagi Grimberg , Thomas Gleixner , Christoph Hellwig , Frederic Weisbecker , Mel Gorman , Hannes Reinecke , Sridhar Balaraman , "brookxu.cn" , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH v2 3/3] lib/group_cpus.c: honor housekeeping config when grouping CPUs Message-ID: References: <20240627-isolcpus-io-queues-v2-0-26a32e3c4f75@suse.de> <20240627-isolcpus-io-queues-v2-3-26a32e3c4f75@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240701_002138_059151_78E5377B X-CRM114-Status: GOOD ( 20.04 ) 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 Mon, Jul 01, 2024 at 09:08:32AM +0200, Daniel Wagner wrote: > On Sun, Jun 30, 2024 at 09:39:59PM GMT, Ming Lei wrote: > > > Make group_cpus_evenly aware of isolcpus configuration and use the > > > housekeeping CPU mask as base for distributing the available CPUs into > > > groups. > > > > > > Fixes: 11ea68f553e2 ("genirq, sched/isolation: Isolate from handling managed interrupts") > > > > isolated CPUs are actually handled when figuring out irq effective mask, > > so not sure how commit 11ea68f553e2 is wrong, and what is fixed in this > > patch from user viewpoint? > > IO queues are allocated/spread on the isolated CPUs and if there is an > thread submitting IOs from an isolated CPU it will cause noise on the > isolated CPUs. The question is this a use case you need/want to support? I have talked RH Openshift team weeks ago and they have such usage. userspace is free to run any application from isolated CPUs via 'taskset -c' even though 'isolcpus=' is passed from command line. Kernel can not add such new constraint on userspace. > We have customers who are complaining that even with isolcpus provided > they still see IO noise on the isolated CPUs. That is another issue, which has been fixed by the following patch: a46c27026da1 blk-mq: don't schedule block kworker on isolated CPUs Thanks, Ming