Commit-ID: c22402a2f76e88b04b7a8b6c0597ad9ba6fd71de Gitweb: http://git.kernel.org/tip/c22402a2f76e88b04b7a8b6c0597ad9ba6fd71de Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> AuthorDate: Fri, 20 Apr 2012 16:57:22 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Wed, 9 May 2012 15:00:51 +0200 sched/fair: Let minimally loaded cpu balance the group Currently we let the leftmost (or first idle) cpu ascend the sched_domain tree and perform load-balancing. The result is that the busiest cpu in the group might be performing this function and pull more load to itself. The next load balance pass will then try to equalize this again. Change this to pick the least loaded cpu to perform higher domain balancing. Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Link: http://lkml.kernel.org/n/tip-v8zlrmgmkne3bkcy9dej1fvm@xxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/sched/fair.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 678966c..968ffee 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3781,7 +3781,8 @@ static inline void update_sg_lb_stats(struct sched_domain *sd, { unsigned long load, max_cpu_load, min_cpu_load, max_nr_running; int i; - unsigned int balance_cpu = -1, first_idle_cpu = 0; + unsigned int balance_cpu = -1; + unsigned long balance_load = ~0UL; unsigned long avg_load_per_task = 0; if (local_group) @@ -3797,12 +3798,11 @@ static inline void update_sg_lb_stats(struct sched_domain *sd, /* Bias balancing toward cpus of our domain */ if (local_group) { - if (idle_cpu(i) && !first_idle_cpu) { - first_idle_cpu = 1; + load = target_load(i, load_idx); + if (load < balance_load || idle_cpu(i)) { + balance_load = load; balance_cpu = i; } - - load = target_load(i, load_idx); } else { load = source_load(i, load_idx); if (load > max_cpu_load) { -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html