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authorWanpeng Li <wanpengli@tencent.com>2019-06-28 16:51:41 +0800
committerIngo Molnar <mingo@kernel.org>2019-07-25 15:51:55 +0200
commite0e8d4911ed2695b12c3a01c15634000ede9bc73 (patch)
treeb8979a4489332dc02e52988d52396627ab263fd6 /kernel/sched/topology.c
parent65d74e91694e1afac40c96fb64a9ef120757729e (diff)
downloadlinux-e0e8d4911ed2695b12c3a01c15634000ede9bc73.tar.bz2
sched/isolation: Prefer housekeeping CPU in local node
In real product setup, there will be houseeking CPUs in each nodes, it is prefer to do housekeeping from local node, fallback to global online cpumask if failed to find houseeking CPU from local node. Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1561711901-4755-2-git-send-email-wanpengli@tencent.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/topology.c')
-rw-r--r--kernel/sched/topology.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index f751ce0b783e..4eea2c9bc732 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1724,6 +1724,26 @@ void sched_domains_numa_masks_clear(unsigned int cpu)
}
}
+/*
+ * sched_numa_find_closest() - given the NUMA topology, find the cpu
+ * closest to @cpu from @cpumask.
+ * cpumask: cpumask to find a cpu from
+ * cpu: cpu to be close to
+ *
+ * returns: cpu, or nr_cpu_ids when nothing found.
+ */
+int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
+{
+ int i, j = cpu_to_node(cpu);
+
+ for (i = 0; i < sched_domains_numa_levels; i++) {
+ cpu = cpumask_any_and(cpus, sched_domains_numa_masks[i][j]);
+ if (cpu < nr_cpu_ids)
+ return cpu;
+ }
+ return nr_cpu_ids;
+}
+
#endif /* CONFIG_NUMA */
static int __sdt_alloc(const struct cpumask *cpu_map)