RE: [RFC PATCH v5 4/4] scheduler: Add cluster scheduler level for x86
From: Song Bao Hua (Barry Song) <hidden>
Date: 2021-03-23 23:21:55
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-----Original Message----- From: Tim Chen [mailto:tim.c.chen@linux.intel.com] Sent: Wednesday, March 24, 2021 11:51 AM To: Song Bao Hua (Barry Song) <redacted>; catalin.marinas@arm.com; will@kernel.org; rjw@rjwysocki.net; vincent.guittot@linaro.org; bp@alien8.de; tglx@linutronix.de; mingo@redhat.com; lenb@kernel.org; peterz@infradead.org; dietmar.eggemann@arm.com; rostedt@goodmis.org; bsegall@google.com; mgorman@suse.de Cc: msys.mizuma@gmail.com; valentin.schneider@arm.com; gregkh@linuxfoundation.org; Jonathan Cameron [off-list ref]; juri.lelli@redhat.com; mark.rutland@arm.com; sudeep.holla@arm.com; aubrey.li@linux.intel.com; linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-acpi@vger.kernel.org; x86@kernel.org; xuwei (O) [off-list ref]; Zengtao (B) [off-list ref]; guodong.xu@linaro.org; yangyicong [off-list ref]; Liguozhu (Kenneth) [off-list ref]; linuxarm@openeuler.org; hpa@zytor.com Subject: Re: [RFC PATCH v5 4/4] scheduler: Add cluster scheduler level for x86 On 3/18/21 9:16 PM, Barry Song wrote:quoted
From: Tim Chen <redacted> There are x86 CPU architectures (e.g. Jacobsville) where L2 cahce is shared among a cluster of cores instead of being exclusive to one single core. To prevent oversubscription of L2 cache, load should be balanced between such L2 clusters, especially for tasks with no shared data. Also with cluster scheduling policy where tasks are woken up in the same L2 cluster, we will benefit from keeping tasks related to each other and likely sharing data in the same L2 cluster. Add CPU masks of CPUs sharing the L2 cache so we can build such L2 cluster scheduler domain. Signed-off-by: Tim Chen <redacted> Signed-off-by: Barry Song <redacted>Barry, Can you also add this chunk to the patch. Thanks.
Sure, Tim, Thanks. I'll put that into patch 4/4 in v6.
quoted hunk ↗ jump to hunk
Timdiff --git a/arch/x86/include/asm/topology.hb/arch/x86/include/asm/topology.h index 2a11ccc14fb1..800fa48c9fcd 100644--- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h@@ -115,6 +115,7 @@ extern unsigned int __max_die_per_package; #ifdef CONFIG_SMP #define topology_die_cpumask(cpu) (per_cpu(cpu_die_map, cpu)) +#define topology_cluster_cpumask(cpu) (cpu_clustergroup_mask(cpu)) #define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu)) #define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
Thanks Barry _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel