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| author | Mel Gorman <mgorman@suse.de> | 2013-10-07 11:28:58 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-10-09 12:40:23 +0200 |
| commit | 688b7585d16ab57a17aa4422a3b290b3a55fa679 (patch) | |
| tree | 2a016719cf05336bf49db699a9268dae6b99310f /kernel/sched | |
| parent | f809ca9a554dda49fb264c79e31c722e0b063ff8 (diff) | |
| download | linux-688b7585d16ab57a17aa4422a3b290b3a55fa679.tar.gz linux-688b7585d16ab57a17aa4422a3b290b3a55fa679.tar.bz2 linux-688b7585d16ab57a17aa4422a3b290b3a55fa679.zip | |
sched/numa: Select a preferred node with the most numa hinting faults
This patch selects a preferred node for a task to run on based on the
NUMA hinting faults. This information is later used to migrate tasks
towards the node during balancing.
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/1381141781-10992-21-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 1 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 17 |
2 files changed, 16 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6808d35fd7ed..d15cd70f85b5 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1633,6 +1633,7 @@ static void __sched_fork(struct task_struct *p) p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0; p->numa_migrate_seq = p->mm ? p->mm->numa_scan_seq - 1 : 0; 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; #endif /* CONFIG_NUMA_BALANCING */ diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0bb3e0aa110b..9efd34f63e81 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -879,7 +879,8 @@ static unsigned int task_scan_max(struct task_struct *p) static void task_numa_placement(struct task_struct *p) { - int seq; + int seq, nid, max_nid = -1; + unsigned long max_faults = 0; if (!p->mm) /* for example, ksmd faulting in a user's mm */ return; @@ -889,7 +890,19 @@ static void task_numa_placement(struct task_struct *p) p->numa_scan_seq = seq; p->numa_scan_period_max = task_scan_max(p); - /* FIXME: Scheduling placement policy hints go here */ + /* Find the node with the highest number of faults */ + for_each_online_node(nid) { + unsigned long faults = p->numa_faults[nid]; + p->numa_faults[nid] >>= 1; + if (faults > max_faults) { + max_faults = faults; + max_nid = nid; + } + } + + /* Update the tasks preferred node if necessary */ + if (max_faults && max_nid != p->numa_preferred_nid) + p->numa_preferred_nid = max_nid; } /* |