From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 2D61FDF5C for ; Mon, 1 Jul 2024 02:09:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719799788; cv=none; b=YueV3PH/nqZIoJt+1FFkL2mf/+dSzWVxvqvjXie5MraHXK1PQXjOCYEc/QZ5eBWWWHTzCCKlugMTZduBqWw4P5AGVL7gCDSawlmf2sGTjyiFEFKWHbg7/s7sA04qkd96J3jpQWMjdr4cAKI1xewVQl4lTZaCtQoJ8Qr65k6Fki8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719799788; c=relaxed/simple; bh=/wd3LnG2ga9Hft6t4lrf1Af+kA3o7IIoJmye8zqEneI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Df2Kpw8es4pa/HxToNdz5WsoQQjJCHRXRmfRB898kMzPkERey9fO1aUAv9JhafNXmJAqosGmQr7Du3JgbBJeIV99yFQ53Uld9o6s/LTSZjlKz3mtThLu2IM9PX9otkFf5kqOOowj0IkEPjTiAjf3lQFeyGgX0Xvi1gM+Mc9rQyU= 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=iN+dYJZ6; arc=none smtp.client-ip=170.10.133.124 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="iN+dYJZ6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719799786; 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=YFBv2GNzfwr96rwHa3FF1YMIpAUxs+Y9neXUQdtqtGE=; b=iN+dYJZ6+v4cYETqV40f7hMKP4S4g24ahVHGl+SrYnjNPm0sS3sQv7mC+ADt3aXeyD2hNI rWahmbmrwBrPdStyMqkvGVxoj3vKlQyzBAA+csWUMDVXx1yHmSC4nmTZGilmvGpjwcYU0Z oViN6fzJzORfPoTSaIyoft7ApEfPqLc= 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-434-rNlGfnrSPya_7Tl82MuDLg-1; Sun, 30 Jun 2024 22:09:42 -0400 X-MC-Unique: rNlGfnrSPya_7Tl82MuDLg-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 03491194510D; Mon, 1 Jul 2024 02:09:34 +0000 (UTC) Received: from fedora (unknown [10.72.112.45]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CB67819560A3; Mon, 1 Jul 2024 02:09:22 +0000 (UTC) Date: Mon, 1 Jul 2024 10:09:17 +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, ming.lei@redhat.com 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: <20240627-isolcpus-io-queues-v2-3-26a32e3c4f75@suse.de> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On Thu, Jun 27, 2024 at 04:10:53PM +0200, Daniel Wagner wrote: > group_cpus_evenly distributes all present CPUs into groups. This ignores > the isolcpus configuration and assigns isolated CPUs into the groups. > > 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") > Signed-off-by: Daniel Wagner > --- > lib/group_cpus.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 73 insertions(+), 2 deletions(-) > > diff --git a/lib/group_cpus.c b/lib/group_cpus.c > index ee272c4cefcc..19fb7186f9d4 100644 > --- a/lib/group_cpus.c > +++ b/lib/group_cpus.c > @@ -8,6 +8,7 @@ > #include > #include > #include > +#include > > #ifdef CONFIG_SMP > > @@ -330,7 +331,7 @@ static int __group_cpus_evenly(unsigned int startgrp, unsigned int numgrps, > } > > /** > - * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality > + * group_possible_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality > * @numgrps: number of groups > * > * Return: cpumask array if successful, NULL otherwise. And each element > @@ -344,7 +345,7 @@ static int __group_cpus_evenly(unsigned int startgrp, unsigned int numgrps, > * We guarantee in the resulted grouping that all CPUs are covered, and > * no same CPU is assigned to multiple groups > */ > -struct cpumask *group_cpus_evenly(unsigned int numgrps) > +static struct cpumask *group_possible_cpus_evenly(unsigned int numgrps) > { > unsigned int curgrp = 0, nr_present = 0, nr_others = 0; > cpumask_var_t *node_to_cpumask; > @@ -423,6 +424,76 @@ struct cpumask *group_cpus_evenly(unsigned int numgrps) > } > return masks; > } > + > +/** > + * group_mask_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality > + * @numgrps: number of groups > + * @cpu_mask: CPU to consider for the grouping > + * > + * Return: cpumask array if successful, NULL otherwise. And each element > + * includes CPUs assigned to this group. > + * > + * Try to put close CPUs from viewpoint of CPU and NUMA locality into > + * same group. Allocate present CPUs on these groups evenly. > + */ > +static struct cpumask *group_mask_cpus_evenly(unsigned int numgrps, > + const struct cpumask *cpu_mask) > +{ > + cpumask_var_t *node_to_cpumask; > + cpumask_var_t nmsk; > + int ret = -ENOMEM; > + struct cpumask *masks = NULL; > + > + if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL)) > + return NULL; > + > + node_to_cpumask = alloc_node_to_cpumask(); > + if (!node_to_cpumask) > + goto fail_nmsk; > + > + masks = kcalloc(numgrps, sizeof(*masks), GFP_KERNEL); > + if (!masks) > + goto fail_node_to_cpumask; > + > + build_node_to_cpumask(node_to_cpumask); > + > + ret = __group_cpus_evenly(0, numgrps, node_to_cpumask, cpu_mask, nmsk, > + masks); > + > +fail_node_to_cpumask: > + free_node_to_cpumask(node_to_cpumask); > + > +fail_nmsk: > + free_cpumask_var(nmsk); > + if (ret < 0) { > + kfree(masks); > + return NULL; > + } > + return masks; > +} > + > +/** > + * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality > + * @numgrps: number of groups > + * > + * Return: cpumask array if successful, NULL otherwise. > + * > + * group_possible_cpus_evently() is used for distributing the cpus on all > + * possible cpus in absence of isolcpus command line argument. > + * group_mask_cpu_evenly() is used when the isolcpus command line > + * argument is used with managed_irq option. In this case only the > + * housekeeping CPUs are considered. > + */ > +struct cpumask *group_cpus_evenly(unsigned int numgrps) > +{ > + const struct cpumask *hk_mask; > + > + hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ); > + if (!cpumask_empty(hk_mask)) > + return group_mask_cpus_evenly(numgrps, hk_mask); > + > + return group_possible_cpus_evenly(numgrps); Since this patch, some isolated CPUs may not be covered in blk-mq queue mapping. Meantime people still may submit IO workload from isolated CPUs such as by 'taskset -c', blk-mq may not work well for this situation, for example, IO hang may be caused during cpu hotplug. I did see this kind of usage in some RH Openshift workloads. If blk-mq problem can be solved, I am fine with this kind of change. Thanks, Ming