From: Mel Gorman <mgorman@suse.de>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@suse.de>
Subject: [PATCH 03/15] sched: Select a preferred node with the most numa hinting faults
Date: Sat, 6 Jul 2013 00:08:50 +0100 [thread overview]
Message-ID: <1373065742-9753-4-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1373065742-9753-1-git-send-email-mgorman@suse.de>
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>
---
include/linux/sched.h | 1 +
kernel/sched/core.c | 1 +
kernel/sched/fair.c | 17 +++++++++++++++--
3 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 72861b4..ba46a64 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1507,6 +1507,7 @@ struct task_struct {
struct callback_head numa_work;
unsigned long *numa_faults;
+ int numa_preferred_nid;
#endif /* CONFIG_NUMA_BALANCING */
struct rcu_head rcu;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f332ec0..ed4e785 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1593,6 +1593,7 @@ 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 904fd6f..c0bee41 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -793,7 +793,8 @@ unsigned int sysctl_numa_balancing_scan_delay = 1000;
static void task_numa_placement(struct task_struct *p)
{
- int seq;
+ int seq, nid, max_nid = 0;
+ unsigned long max_faults = 0;
if (!p->mm) /* for example, ksmd faulting in a user's mm */
return;
@@ -802,7 +803,19 @@ static void task_numa_placement(struct task_struct *p)
return;
p->numa_scan_seq = seq;
- /* FIXME: Scheduling placement policy hints go here */
+ /* Find the node with the highest number of faults */
+ for (nid = 0; nid < nr_node_ids; 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;
}
/*
--
1.8.1.4
--
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next prev parent reply other threads:[~2013-07-05 23:09 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-05 23:08 [PATCH 0/15] Basic scheduler support for automatic NUMA balancing V3 Mel Gorman
2013-07-05 23:08 ` [PATCH 01/15] mm: numa: Document automatic NUMA balancing sysctls Mel Gorman
2013-07-05 23:08 ` [PATCH 02/15] sched: Track NUMA hinting faults on per-node basis Mel Gorman
2013-07-05 23:08 ` Mel Gorman [this message]
2013-07-05 23:08 ` [PATCH 04/15] sched: Update NUMA hinting faults once per scan Mel Gorman
2013-07-05 23:08 ` [PATCH 05/15] sched: Favour moving tasks towards the preferred node Mel Gorman
2013-07-05 23:08 ` [PATCH 06/15] sched: Reschedule task on preferred NUMA node once selected Mel Gorman
2013-07-06 10:38 ` Peter Zijlstra
2013-07-08 8:34 ` Mel Gorman
2013-07-05 23:08 ` [PATCH 07/15] sched: Add infrastructure for split shared/private accounting of NUMA hinting faults Mel Gorman
2013-07-05 23:08 ` [PATCH 08/15] sched: Increase NUMA PTE scanning when a new preferred node is selected Mel Gorman
2013-07-05 23:08 ` [PATCH 09/15] sched: Check current->mm before allocating NUMA faults Mel Gorman
2013-07-05 23:08 ` [PATCH 10/15] sched: Set the scan rate proportional to the size of the task being scanned Mel Gorman
2013-07-05 23:08 ` [PATCH 11/15] mm: numa: Scan pages with elevated page_mapcount Mel Gorman
2013-07-05 23:08 ` [PATCH 12/15] sched: Remove check that skips small VMAs Mel Gorman
2013-07-05 23:09 ` [PATCH 13/15] sched: Set preferred NUMA node based on number of private faults Mel Gorman
2013-07-06 10:41 ` Peter Zijlstra
2013-07-08 9:23 ` Mel Gorman
2013-07-06 10:44 ` Peter Zijlstra
2013-07-05 23:09 ` [PATCH 14/15] sched: Account for the number of preferred tasks running on a node when selecting a preferred node Mel Gorman
2013-07-06 10:46 ` Peter Zijlstra
2013-07-05 23:09 ` [PATCH 15/15] sched: Favour moving tasks towards nodes that incurred more faults Mel Gorman
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