sched/numa: Initialise numa_next_scan properly

Scan delay logic and resets are currently initialised to start scanning
immediately instead of delaying properly. Initialise them properly at
fork time and catch when a new mm has been allocated.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-17-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f575d5b..aee7e4d 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1624,8 +1624,8 @@ static void __sched_fork(struct task_struct *p)
 
 #ifdef CONFIG_NUMA_BALANCING
        if (p->mm && atomic_read(&p->mm->mm_users) == 1) {
-               p->mm->numa_next_scan = jiffies;
-               p->mm->numa_next_reset = jiffies;
+               p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
+               p->mm->numa_next_reset = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_period_reset);
                p->mm->numa_scan_seq = 0;
        }
 

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 49b11fa..0966f0c 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -900,6 +900,13 @@ void task_numa_work(struct callback_head *work)
        if (p->flags & PF_EXITING)
                return;
 
+       if (!mm->numa_next_reset || !mm->numa_next_scan) {
+               mm->numa_next_scan = now +
+                       msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
+               mm->numa_next_reset = now +
+                       msecs_to_jiffies(sysctl_numa_balancing_scan_period_reset);
+       }
+
        /*
         * Reset the scan period if enough time has gone by. Objective is that
         * scanning will be reduced if pages are properly placed. As tasks