From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A45E61FC4 for ; Mon, 1 Jul 2024 07:21:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719818497; cv=none; b=VSF3H/vdXw37cWGMbi1np+f9pNanOwweBP+22mUxaWVBAXrZObCf1QsaSMlAfoq5QqtWLBHW7Cy1UdYefvZ1nlo8bkGT+qy4rQYCFKJ587Z8M3brivn59YxgjKftcjDdh5N7YYYS5GNSIlcfdGAM1n+WoEe3MlQkDzomRN1yWD8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719818497; c=relaxed/simple; bh=3fZtaBbbZzsHhLK/3C1yQIXRmJwQkiJgXyvRD2amXCU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=O84a0p2baDsXbTPr1z8Bpeqiig2PTg6NOw9N1cV3bhXuIdeXN3dZ6+ItKTTQWnDJ8MprOieCe8uL4G6dVtLGz7FIA3AnUjd9QMV6sTkf3vZCnMbe1o8paxP/wQrpdpdJLlgbNqrIWLeczQYTAfzY1Be9NPxpmFTm41VgpQeFwO0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=jAe/qCCt; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="jAe/qCCt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719818495; 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=jAe/qCCtMxor1/lz4kI2ZWVPju4UPSR1dMWBv8ikGPYlP7crddTiQ2vDvZtipLOBYrVob1 ifIfzzLNtTGAhyp5DYEUB5ag6nmKzPV1u1Mpx3Z5m8bhKFFiSWeJIyRBi5oqBNn0w+Rwll HeENownzDgPmvyMxT4mZJf+SnOsMkhM= 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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