From patchwork Tue Aug 16 18:07:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Valentin Schneider X-Patchwork-Id: 12945180 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AC1DC25B0E for ; Tue, 16 Aug 2022 18:08:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236993AbiHPSIT (ORCPT ); Tue, 16 Aug 2022 14:08:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236934AbiHPSHy (ORCPT ); Tue, 16 Aug 2022 14:07:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EF9C85FDF for ; Tue, 16 Aug 2022 11:07:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660673264; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qZr7gdCnQUFeKt5ugQdZLofQqTfC3GDipKWYJIctC0o=; b=RsTC7p/RmGUnFOh53qXF8Z4ItmXGIkd19R2tC3DPyflaW9lA67PEAqnqDuP2UdzAEJkfLg ZKcSHb3IYXaDkPi9E7AEI9g/+cgq+3XdEQdW5MIh6XuJ938kMT5g2mjamL6bnqlm+o1gZ4 8cfSWyxYlYyzWYsLnv9zoN+24JoaRXs= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-154-caT8VHlLMuKRC0hw8qYKXw-1; Tue, 16 Aug 2022 14:07:42 -0400 X-MC-Unique: caT8VHlLMuKRC0hw8qYKXw-1 Received: by mail-wm1-f69.google.com with SMTP id f7-20020a1c6a07000000b003a60ede816cso318466wmc.0 for ; Tue, 16 Aug 2022 11:07:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=qZr7gdCnQUFeKt5ugQdZLofQqTfC3GDipKWYJIctC0o=; b=nHg7sCo6/mUGphs2OZsZp4q1X0kqI0dqSxXIlvWIqVQnFOseADP1lgU2/YUanHAWnE HQhz9EIIvbOCtJPM4YgaK/y1eUMhioZqmJkBJGUrcwMw8j/+Nam6ta/zFwj62fNC6owK yQFi0wg8xR1pBK3O1/5MO5vnSy/4DVJEYBfKd+DjY9ISNVDHUtU4KW2k+tnvdUt5Z1XM KmasyoWJ4cn+otWZ0gkCxMsEBkRH91a4uNUfIFATOCjQhzr+dSrzPl6AGPO1HgX86VlK iZJ4oQWEgyldY3ZdnGS83JXQ0H7sakYbm9sc5Z+LTin+RJszXtt/rcAL2TUX0UDGHh3m /BVA== X-Gm-Message-State: ACgBeo28WOZkRHaVZf0VwK1jFP3dglrVN3aIzwRgCOYMU5s0ELqCu4CG LKZAhJ0AQUJruz/SRK+yn5XEQDpX5927Q/PSHyzxLQSJLJ9OhDSTjm0jbEAeStVHku4JlTOTbsa kIqrGE09kLmAs3SrymMc5pg== X-Received: by 2002:a7b:c852:0:b0:3a5:407a:76df with SMTP id c18-20020a7bc852000000b003a5407a76dfmr13708349wml.101.1660673260911; Tue, 16 Aug 2022 11:07:40 -0700 (PDT) X-Google-Smtp-Source: AA6agR7UPXSQNMLUdzm2OIU4YmRzUCveA1esyoYO7MxQEQacoH/hwrHSpxGq4VehHXhVW3FIbjDgTw== X-Received: by 2002:a7b:c852:0:b0:3a5:407a:76df with SMTP id c18-20020a7bc852000000b003a5407a76dfmr13708328wml.101.1660673260684; Tue, 16 Aug 2022 11:07:40 -0700 (PDT) Received: from vschneid.remote.csb ([185.11.37.247]) by smtp.gmail.com with ESMTPSA id o8-20020a05600c4fc800b003a319bd3278sm14694961wmq.40.2022.08.16.11.07.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Aug 2022 11:07:40 -0700 (PDT) From: Valentin Schneider To: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Saeed Mahameed , Leon Romanovsky , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Yury Norov , Andy Shevchenko , Rasmus Villemoes , Ingo Molnar , Peter Zijlstra , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Mel Gorman , Greg Kroah-Hartman , Barry Song , Heiko Carstens , Tony Luck , Jonathan Cameron , Gal Pressman , Tariq Toukan Subject: [PATCH 3/5] sched/topology: Introduce sched_numa_hop_mask() Date: Tue, 16 Aug 2022 19:07:25 +0100 Message-Id: <20220816180727.387807-4-vschneid@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220816180727.387807-1-vschneid@redhat.com> References: <20220816180727.387807-1-vschneid@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Tariq has pointed out that drivers allocating IRQ vectors would benefit from having smarter NUMA-awareness - cpumask_local_spread() only knows about the local node and everything outside is in the same bucket. sched_domains_numa_masks is pretty much what we want to hand out (a cpumask of CPUs reachable within a given distance budget), introduce sched_numa_hop_mask() to export those cpumasks. Link: http://lore.kernel.org/r/20220728191203.4055-1-tariqt@nvidia.com Signed-off-by: Valentin Schneider --- include/linux/topology.h | 9 +++++++++ kernel/sched/topology.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/include/linux/topology.h b/include/linux/topology.h index 4564faafd0e1..13b82b83e547 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -245,5 +245,14 @@ static inline const struct cpumask *cpu_cpu_mask(int cpu) return cpumask_of_node(cpu_to_node(cpu)); } +#ifdef CONFIG_NUMA +extern const struct cpumask *sched_numa_hop_mask(int node, int hops); +#else +static inline const struct cpumask *sched_numa_hop_mask(int node, int hops) +{ + return ERR_PTR(-EOPNOTSUPP); +} +#endif /* CONFIG_NUMA */ + #endif /* _LINUX_TOPOLOGY_H */ diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 8739c2a5a54e..f0236a0ae65c 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -2067,6 +2067,34 @@ int sched_numa_find_closest(const struct cpumask *cpus, int cpu) return found; } +/** + * sched_numa_hop_mask() - Get the cpumask of CPUs at most @hops hops away. + * @node: The node to count hops from. + * @hops: Include CPUs up to that many hops away. 0 means local node. + * + * Requires rcu_lock to be held. Returned cpumask is only valid within that + * read-side section, copy it if required beyond that. + * + * Note that not all hops are equal in size; see sched_init_numa() for how + * distances and masks are handled. + * + * Also note that this is a reflection of sched_domains_numa_masks, which may change + * during the lifetime of the system (offline nodes are taken out of the masks). + */ +const struct cpumask *sched_numa_hop_mask(int node, int hops) +{ + struct cpumask ***masks = rcu_dereference(sched_domains_numa_masks); + + if (node >= nr_node_ids || hops >= sched_domains_numa_levels) + return ERR_PTR(-EINVAL); + + if (!masks) + return NULL; + + return masks[hops][node]; +} +EXPORT_SYMBOL_GPL(sched_numa_hop_mask); + #endif /* CONFIG_NUMA */ static int __sdt_alloc(const struct cpumask *cpu_map)