From 1e3646ffc64b232cb14a5ef01d7b98997c1b73f9 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Mon, 7 Oct 2013 11:29:38 +0100 Subject: [PATCH] mm: numa: Revert temporarily disabling of NUMA migration With the scan rate code working (at least for multi-instance specjbb), the large hammer that is "sched: Do not migrate memory immediately after switching node" can be replaced with something smarter. Revert temporarily migration disabling and all traces of numa_migrate_seq. Signed-off-by: Rik van Riel Signed-off-by: Mel Gorman Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1381141781-10992-61-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar --- include/linux/sched.h | 1 - kernel/sched/core.c | 2 -- kernel/sched/fair.c | 25 +------------------------ mm/mempolicy.c | 12 ------------ 4 files changed, 1 insertion(+), 39 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 2292f6c..d24f70f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1340,7 +1340,6 @@ struct task_struct { #endif #ifdef CONFIG_NUMA_BALANCING int numa_scan_seq; - int numa_migrate_seq; unsigned int numa_scan_period; unsigned int numa_scan_period_max; unsigned long numa_migrate_retry; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 89c5ae8..0c3feeb 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1731,7 +1731,6 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) p->node_stamp = 0ULL; p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0; - p->numa_migrate_seq = 1; p->numa_scan_period = sysctl_numa_balancing_scan_delay; p->numa_work.next = &p->numa_work; p->numa_faults = NULL; @@ -4488,7 +4487,6 @@ void sched_setnuma(struct task_struct *p, int nid) p->sched_class->put_prev_task(rq, p); p->numa_preferred_nid = nid; - p->numa_migrate_seq = 1; if (running) p->sched_class->set_curr_task(rq); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index da6fa22..8454c38 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1261,16 +1261,8 @@ static void numa_migrate_preferred(struct task_struct *p) { /* Success if task is already running on preferred CPU */ p->numa_migrate_retry = 0; - if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid) { - /* - * If migration is temporarily disabled due to a task migration - * then re-enable it now as the task is running on its - * preferred node and memory should migrate locally - */ - if (!p->numa_migrate_seq) - p->numa_migrate_seq++; + if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid) return; - } /* This task has no NUMA fault statistics yet */ if (unlikely(p->numa_preferred_nid == -1)) @@ -1367,7 +1359,6 @@ static void task_numa_placement(struct task_struct *p) if (p->numa_scan_seq == seq) return; p->numa_scan_seq = seq; - p->numa_migrate_seq++; p->numa_scan_period_max = task_scan_max(p); /* If the task is part of a group prevent parallel updates to group stats */ @@ -4730,20 +4721,6 @@ static void move_task(struct task_struct *p, struct lb_env *env) set_task_cpu(p, env->dst_cpu); activate_task(env->dst_rq, p, 0); check_preempt_curr(env->dst_rq, p, 0); -#ifdef CONFIG_NUMA_BALANCING - if (p->numa_preferred_nid != -1) { - int src_nid = cpu_to_node(env->src_cpu); - int dst_nid = cpu_to_node(env->dst_cpu); - - /* - * If the load balancer has moved the task then limit - * migrations from taking place in the short term in - * case this is a short-lived migration. - */ - if (src_nid != dst_nid && dst_nid != p->numa_preferred_nid) - p->numa_migrate_seq = 0; - } -#endif } /* diff --git a/mm/mempolicy.c b/mm/mempolicy.c index a5867ef..2929c24 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2404,18 +2404,6 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long last_cpupid = page_cpupid_xchg_last(page, this_cpupid); if (!cpupid_pid_unset(last_cpupid) && cpupid_to_nid(last_cpupid) != thisnid) goto out; - -#ifdef CONFIG_NUMA_BALANCING - /* - * If the scheduler has just moved us away from our - * preferred node, do not bother migrating pages yet. - * This way a short and temporary process migration will - * not cause excessive memory migration. - */ - if (thisnid != current->numa_preferred_nid && - !current->numa_migrate_seq) - goto out; -#endif } if (curnid != polnid) -- 2.7.4