Commit 22da9569 authored Jun 04, 2013 by Viresh Kumar Committed by Ingo Molnar Jun 19, 2013

sched: Optimize build_sched_domains() for saving first SD node for a cpu



We are saving first scheduling domain for a cpu in build_sched_domains() by
iterating over the nested sd->child list. We don't actually need to do it this
way.

tl will be equal to sched_domain_topology for the first iteration and so we can
set *per_cpu_ptr(d.sd, i) based on that.  So, save pointer to first SD while
running the iteration loop over tl's.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/fc473527cbc4dfa0b8eeef2a59db74684eb59a83.1370436120.git.viresh.kumar@linaro.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 4a850cbe

kernel/sched/core.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -5985,16 +5985,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
		sd = NULL;
		for (tl = sched_domain_topology; tl->init; tl++) {
		sd = build_sched_domain(tl, cpu_map, attr, sd, i);
		if (tl == sched_domain_topology)
		*per_cpu_ptr(d.sd, i) = sd;
		if (tl->flags & SDTL_OVERLAP \|\| sched_feat(FORCE_SD_OVERLAP))
		sd->flags \|= SD_OVERLAP;
		if (cpumask_equal(cpu_map, sched_domain_span(sd)))
		break;
		}

		while (sd->child)
		sd = sd->child;

		*per_cpu_ptr(d.sd, i) = sd;
		}

		/* Build the groups for the domains */

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