From 5e1576ed0e54d419286a8096133029062b6ad456 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Mon, 7 Oct 2013 11:29:26 +0100 Subject: [PATCH] sched/numa: Stay on the same node if CLONE_VM A newly spawned thread inside a process should stay on the same NUMA node as its parent. This prevents processes from being "torn" across multiple NUMA nodes every time they spawn a new thread. 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/1381141781-10992-49-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 +- kernel/fork.c | 2 +- kernel/sched/core.c | 14 +++++++++----- 3 files changed, 11 insertions(+), 7 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index ff54385..8563e3d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2021,7 +2021,7 @@ extern void wake_up_new_task(struct task_struct *tsk); #else static inline void kick_process(struct task_struct *tsk) { } #endif -extern void sched_fork(struct task_struct *p); +extern void sched_fork(unsigned long clone_flags, struct task_struct *p); extern void sched_dead(struct task_struct *p); extern void proc_caches_init(void); diff --git a/kernel/fork.c b/kernel/fork.c index 7192d91..c93be06 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1310,7 +1310,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, #endif /* Perform scheduler related setup. Assign this task to a CPU. */ - sched_fork(p); + sched_fork(clone_flags, p); retval = perf_event_init_task(p); if (retval) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 51092d5..3e2c893 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1696,7 +1696,7 @@ int wake_up_state(struct task_struct *p, unsigned int state) * * __sched_fork() is basic setup used by init_idle() too: */ -static void __sched_fork(struct task_struct *p) +static void __sched_fork(unsigned long clone_flags, struct task_struct *p) { p->on_rq = 0; @@ -1725,11 +1725,15 @@ static void __sched_fork(struct task_struct *p) p->mm->numa_scan_seq = 0; } + if (clone_flags & CLONE_VM) + p->numa_preferred_nid = current->numa_preferred_nid; + else + p->numa_preferred_nid = -1; + 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_preferred_nid = -1; p->numa_work.next = &p->numa_work; p->numa_faults = NULL; p->numa_faults_buffer = NULL; @@ -1761,12 +1765,12 @@ void set_numabalancing_state(bool enabled) /* * fork()/clone()-time setup: */ -void sched_fork(struct task_struct *p) +void sched_fork(unsigned long clone_flags, struct task_struct *p) { unsigned long flags; int cpu = get_cpu(); - __sched_fork(p); + __sched_fork(clone_flags, p); /* * We mark the process as running here. This guarantees that * nobody will actually run it, and a signal or other external @@ -4287,7 +4291,7 @@ void init_idle(struct task_struct *idle, int cpu) raw_spin_lock_irqsave(&rq->lock, flags); - __sched_fork(idle); + __sched_fork(0, idle); idle->state = TASK_RUNNING; idle->se.exec_start = sched_clock(); -- 2.7.4