From 7142d17e8f935fa842e9f6eece2281b6d41625d6 Mon Sep 17 00:00:00 2001 From: Hillf Danton Date: Thu, 5 May 2011 20:53:20 +0800 Subject: [PATCH] sched: Shorten the construction of the span cpu mask of sched domain For a given node, when constructing the cpumask for its sched_domain to span, if there is no best node available after searching, further efforts could be saved, based on small change in the return value of find_next_best_node(). Signed-off-by: Hillf Danton Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Yong Zhang Link: http://lkml.kernel.org/r/BANLkTi%3DqPWxRAa6%2BdT3ohEP6Z%3D0v%2Be4EXA@mail.gmail.com Signed-off-by: Ingo Molnar --- kernel/sched.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 3d8a1b2680ee..da9338150484 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6807,7 +6807,7 @@ __setup("isolcpus=", isolated_cpu_setup); */ static int find_next_best_node(int node, nodemask_t *used_nodes) { - int i, n, val, min_val, best_node = 0; + int i, n, val, min_val, best_node = -1; min_val = INT_MAX; @@ -6831,7 +6831,8 @@ static int find_next_best_node(int node, nodemask_t *used_nodes) } } - node_set(best_node, *used_nodes); + if (best_node != -1) + node_set(best_node, *used_nodes); return best_node; } @@ -6857,7 +6858,8 @@ static void sched_domain_node_span(int node, struct cpumask *span) for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { int next_node = find_next_best_node(node, &used_nodes); - + if (next_node < 0) + break; cpumask_or(span, span, cpumask_of_node(next_node)); } }