From patchwork Mon Jan 22 16:00:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Souradeep Chakrabarti X-Patchwork-Id: 13525682 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C20114CDFF; Mon, 22 Jan 2024 16:01:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705939268; cv=none; b=mmKNjd5DQ520O/F1AaNT8wDhcKvwZYGvKWF7L4Vd2XBQEb78LVF4aw+z3OM2Myzjmbc3H7WrBFo3ls/3H8Kh/aDoW9J/z58AtAGm8eQ7LjalrespIY/nk6yWcP5ucEnAaHv3TBGiQehdPGsUlYHQI05AeyfPCfQnge55sY5Z/4M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705939268; c=relaxed/simple; bh=N8bi7iOk7SkztwFK/cTk8Cvbzl4tKg+IpZOOTeXUr6o=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=ryYj9hDnYEGnj6gMPOIHMh3hp4yE4ei5b/6a6TP7UTX77VlDD3hTIq2kWXY33Ww3fkfzoqnLYryEUDTFwSGKcxdcO3Rq2FVJXdxMHm7EU4e9Q+t0o2HiWC9MS9x+iq9QNu8rgE4BzobL4jHF1sBVfh3hdVw4VUQl3xhF8USbuZ0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=SubS0tyP; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="SubS0tyP" Received: by linux.microsoft.com (Postfix, from userid 1099) id 6E9C320E2C18; Mon, 22 Jan 2024 08:01:06 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 6E9C320E2C18 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1705939266; bh=cbmGLa7jFFF/JRYGhEzNHaYORqYhPABgjUC6W0VOrNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SubS0tyP8urJZaV8+SNr5Mkqmw9yXRsJhNyyr4V5+6DV7itg2ID45oGaGKIrssbbh ghRzfxu3Ebzvpvtj3LbIdMVYlX8scdA4VTb+4imrCnnzru9vRrAcidMD0yf6eCzC6h C0UJK4W/oXcKKXZ0+52O9z3n7r36Ol8G/Iudqd4s= From: Souradeep Chakrabarti To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, longli@microsoft.com, yury.norov@gmail.com, leon@kernel.org, cai.huoqing@linux.dev, ssengar@linux.microsoft.com, vkuznets@redhat.com, tglx@linutronix.de, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org Cc: schakrabarti@microsoft.com, paulros@microsoft.com Subject: [PATCH 3/4 V2 net-next] net: mana: add a function to spread IRQs per CPUs Date: Mon, 22 Jan 2024 08:00:58 -0800 Message-Id: <1705939259-2859-4-git-send-email-schakrabarti@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1705939259-2859-1-git-send-email-schakrabarti@linux.microsoft.com> References: <1705939259-2859-1-git-send-email-schakrabarti@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: From: Yury Norov Souradeep investigated that the driver performs faster if IRQs are spread on CPUs with the following heuristics: 1. No more than one IRQ per CPU, if possible; 2. NUMA locality is the second priority; 3. Sibling dislocality is the last priority. Let's consider this topology: Node 0 1 Core 0 1 2 3 CPU 0 1 2 3 4 5 6 7 The most performant IRQ distribution based on the above topology and heuristics may look like this: IRQ Nodes Cores CPUs 0 1 0 0-1 1 1 1 2-3 2 1 0 0-1 3 1 1 2-3 4 2 2 4-5 5 2 3 6-7 6 2 2 4-5 7 2 3 6-7 The irq_setup() routine introduced in this patch leverages the for_each_numa_hop_mask() iterator and assigns IRQs to sibling groups as described above. According to [1], for NUMA-aware but sibling-ignorant IRQ distribution based on cpumask_local_spread() performance test results look like this: ./ntttcp -r -m 16 NTTTCP for Linux 1.4.0 --------------------------------------------------------- 08:05:20 INFO: 17 threads created 08:05:28 INFO: Network activity progressing... 08:06:28 INFO: Test run completed. 08:06:28 INFO: Test cycle finished. 08:06:28 INFO: ##### Totals: ##### 08:06:28 INFO: test duration :60.00 seconds 08:06:28 INFO: total bytes :630292053310 08:06:28 INFO: throughput :84.04Gbps 08:06:28 INFO: retrans segs :4 08:06:28 INFO: cpu cores :192 08:06:28 INFO: cpu speed :3799.725MHz 08:06:28 INFO: user :0.05% 08:06:28 INFO: system :1.60% 08:06:28 INFO: idle :96.41% 08:06:28 INFO: iowait :0.00% 08:06:28 INFO: softirq :1.94% 08:06:28 INFO: cycles/byte :2.50 08:06:28 INFO: cpu busy (all) :534.41% For NUMA- and sibling-aware IRQ distribution, the same test works 15% faster: ./ntttcp -r -m 16 NTTTCP for Linux 1.4.0 --------------------------------------------------------- 08:08:51 INFO: 17 threads created 08:08:56 INFO: Network activity progressing... 08:09:56 INFO: Test run completed. 08:09:56 INFO: Test cycle finished. 08:09:56 INFO: ##### Totals: ##### 08:09:56 INFO: test duration :60.00 seconds 08:09:56 INFO: total bytes :741966608384 08:09:56 INFO: throughput :98.93Gbps 08:09:56 INFO: retrans segs :6 08:09:56 INFO: cpu cores :192 08:09:56 INFO: cpu speed :3799.791MHz 08:09:56 INFO: user :0.06% 08:09:56 INFO: system :1.81% 08:09:56 INFO: idle :96.18% 08:09:56 INFO: iowait :0.00% 08:09:56 INFO: softirq :1.95% 08:09:56 INFO: cycles/byte :2.25 08:09:56 INFO: cpu busy (all) :569.22% [1] https://lore.kernel.org/all/20231211063726.GA4977@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net/ Signed-off-by: Yury Norov Co-developed-by: Souradeep Chakrabarti --- .../net/ethernet/microsoft/mana/gdma_main.c | 29 +++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c index d33b27214539..05a0ac054823 100644 --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c @@ -1249,6 +1249,35 @@ void mana_gd_free_res_map(struct gdma_resource *r) r->size = 0; } +static __maybe_unused int irq_setup(unsigned int *irqs, unsigned int len, int node) +{ + const struct cpumask *next, *prev = cpu_none_mask; + cpumask_var_t cpus __free(free_cpumask_var); + int cpu, weight; + + if (!alloc_cpumask_var(&cpus, GFP_KERNEL)) + return -ENOMEM; + + rcu_read_lock(); + for_each_numa_hop_mask(next, node) { + weight = cpumask_weight_andnot(next, prev); + while (weight > 0) { + cpumask_andnot(cpus, next, prev); + for_each_cpu(cpu, cpus) { + if (len-- == 0) + goto done; + irq_set_affinity_and_hint(*irqs++, topology_sibling_cpumask(cpu)); + cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu)); + --weight; + } + } + prev = next; + } +done: + rcu_read_unlock(); + return 0; +} + static int mana_gd_setup_irqs(struct pci_dev *pdev) { unsigned int max_queues_per_port = num_online_cpus();