Commit-ID: 6dc1a672ab15604947361dcd02e459effa09bad5 Gitweb: http://git.kernel.org/tip/6dc1a672ab15604947361dcd02e459effa09bad5 Author: Rik van Riel <r...@redhat.com> AuthorDate: Mon, 23 Jun 2014 11:46:14 -0400 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sat, 5 Jul 2014 11:17:35 +0200
sched/numa: Use effective_load() to balance NUMA loads When CONFIG_FAIR_GROUP_SCHED is enabled, the load that a task places on a CPU is determined by the group the task is in. The active groups on the source and destination CPU can be different, resulting in a different load contribution by the same task at its source and at its destination. As a result, the load needs to be calculated separately for each CPU, instead of estimated once with task_h_load(). Getting this calculation right allows some workloads to converge, where previously the last thread could get stuck on another node, without being able to migrate to its final destination. Signed-off-by: Rik van Riel <r...@redhat.com> Cc: mgor...@suse.de Cc: chegu_vi...@hp.com Cc: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/1403538378-31571-3-git-send-email-r...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/fair.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f287d0b..d6526d2 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1151,6 +1151,7 @@ static void task_numa_compare(struct task_numa_env *env, struct rq *src_rq = cpu_rq(env->src_cpu); struct rq *dst_rq = cpu_rq(env->dst_cpu); struct task_struct *cur; + struct task_group *tg; long src_load, dst_load; long load; long imp = (groupimp > 0) ? groupimp : taskimp; @@ -1225,14 +1226,21 @@ static void task_numa_compare(struct task_numa_env *env, * In the overloaded case, try and keep the load balanced. */ balance: - load = task_h_load(env->p); - dst_load = env->dst_stats.load + load; - src_load = env->src_stats.load - load; + src_load = env->src_stats.load; + dst_load = env->dst_stats.load; + + /* Calculate the effect of moving env->p from src to dst. */ + load = env->p->se.load.weight; + tg = task_group(env->p); + src_load += effective_load(tg, env->src_cpu, -load, -load); + dst_load += effective_load(tg, env->dst_cpu, load, load); if (cur) { - load = task_h_load(cur); - dst_load -= load; - src_load += load; + /* Cur moves in the opposite direction. */ + load = cur->se.load.weight; + tg = task_group(cur); + src_load += effective_load(tg, env->src_cpu, load, load); + dst_load += effective_load(tg, env->dst_cpu, -load, -load); } if (load_too_imbalanced(src_load, dst_load, env)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
