From: Mel Gorman <mgorman@suse.de>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>, Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
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 19/27] sched: Resist moving tasks towards nodes with fewer hinting faults
Date: Thu, 8 Aug 2013 15:00:31 +0100 [thread overview]
Message-ID: <1375970439-5111-20-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1375970439-5111-1-git-send-email-mgorman@suse.de>
Just as "sched: Favour moving tasks towards the preferred node" favours
moving tasks towards nodes with a higher number of recorded NUMA hinting
faults, this patch resists moving tasks towards nodes with lower faults.
[mgorman@suse.de: changelog]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
kernel/sched/fair.c | 33 +++++++++++++++++++++++++++++++++
kernel/sched/features.h | 8 ++++++++
2 files changed, 41 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index dad3ae9..f828803 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4057,12 +4057,43 @@ static bool migrate_improves_locality(struct task_struct *p, struct lb_env *env)
return false;
}
+
+
+static bool migrate_degrades_locality(struct task_struct *p, struct lb_env *env)
+{
+ int src_nid, dst_nid;
+
+ if (!sched_feat(NUMA) || !sched_feat(NUMA_RESIST_LOWER))
+ return false;
+
+ if (!p->numa_faults || !(env->sd->flags & SD_NUMA))
+ return false;
+
+ src_nid = cpu_to_node(env->src_cpu);
+ dst_nid = cpu_to_node(env->dst_cpu);
+
+ if (src_nid == dst_nid ||
+ p->numa_migrate_seq >= sysctl_numa_balancing_settle_count)
+ return false;
+
+ if (p->numa_faults[dst_nid] < p->numa_faults[src_nid])
+ return true;
+
+ return false;
+}
+
#else
static inline bool migrate_improves_locality(struct task_struct *p,
struct lb_env *env)
{
return false;
}
+
+static inline bool migrate_degrades_locality(struct task_struct *p,
+ struct lb_env *env)
+{
+ return false;
+}
#endif
/*
@@ -4125,6 +4156,8 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
* 3) too many balance attempts have failed.
*/
tsk_cache_hot = task_hot(p, rq_clock_task(env->src_rq), env->sd);
+ if (!tsk_cache_hot)
+ tsk_cache_hot = migrate_degrades_locality(p, env);
if (migrate_improves_locality(p, env)) {
#ifdef CONFIG_SCHEDSTATS
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index d9278ce..5716929 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -74,4 +74,12 @@ SCHED_FEAT(NUMA, false)
* balancing.
*/
SCHED_FEAT(NUMA_FAVOUR_HIGHER, true)
+
+/*
+ * NUMA_RESIST_LOWER will resist moving tasks towards nodes where a
+ * lower number of hinting faults have been recorded. As this has
+ * the potential to prevent a task ever migrating to a new node
+ * due to CPU overload it is disabled by default.
+ */
+SCHED_FEAT(NUMA_RESIST_LOWER, false)
#endif
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-08-08 14:01 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-08 14:00 [PATCH 0/27] Basic scheduler support for automatic NUMA balancing V6 Mel Gorman
2013-08-08 14:00 ` [PATCH 01/27] mm: numa: Document automatic NUMA balancing sysctls Mel Gorman
2013-08-08 14:00 ` [PATCH 02/27] sched, numa: Comment fixlets Mel Gorman
2013-08-08 14:00 ` [PATCH 03/27] mm: numa: Account for THP numa hinting faults on the correct node Mel Gorman
2013-08-08 14:00 ` [PATCH 04/27] mm: numa: Do not migrate or account for hinting faults on the zero page Mel Gorman
2013-08-08 14:00 ` [PATCH 05/27] mm, numa: Sanitize task_numa_fault() callsites Mel Gorman
2013-08-08 14:00 ` [PATCH 06/27] sched, numa: Mitigate chance that same task always updates PTEs Mel Gorman
2013-08-08 14:00 ` [PATCH 07/27] sched, numa: Continue PTE scanning even if migrate rate limited Mel Gorman
2013-08-08 14:00 ` [PATCH 08/27] Revert "mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node" Mel Gorman
2013-08-08 14:00 ` [PATCH 09/27] sched: numa: Initialise numa_next_scan properly Mel Gorman
2013-08-08 14:00 ` [PATCH 10/27] sched: numa: Slow scan rate if no NUMA hinting faults are being recorded Mel Gorman
2013-08-08 14:00 ` [PATCH 11/27] sched: Set the scan rate proportional to the memory usage of the task being scanned Mel Gorman
2013-08-08 14:00 ` [PATCH 12/27] sched: numa: Correct adjustment of numa_scan_period Mel Gorman
2013-08-08 14:00 ` [PATCH 13/27] mm: Only flush TLBs if a transhuge PMD is modified for NUMA pte scanning Mel Gorman
2013-08-08 14:00 ` [PATCH 14/27] mm: Do not flush TLB during protection change if !pte_present && !migration_entry Mel Gorman
2013-08-08 14:00 ` [PATCH 15/27] sched: Track NUMA hinting faults on per-node basis Mel Gorman
2013-08-08 14:00 ` [PATCH 16/27] sched: Select a preferred node with the most numa hinting faults Mel Gorman
2013-08-08 14:00 ` [PATCH 17/27] sched: Update NUMA hinting faults once per scan Mel Gorman
2013-08-08 14:00 ` [PATCH 18/27] sched: Favour moving tasks towards the preferred node Mel Gorman
2013-08-08 14:00 ` Mel Gorman [this message]
2013-08-08 14:00 ` [PATCH 20/27] sched: Reschedule task on preferred NUMA node once selected Mel Gorman
2013-08-08 14:00 ` [PATCH 21/27] sched: Add infrastructure for split shared/private accounting of NUMA hinting faults Mel Gorman
2013-08-08 14:00 ` [PATCH 22/27] sched: Check current->mm before allocating NUMA faults Mel Gorman
2013-08-08 14:00 ` [PATCH 23/27] mm: numa: Scan pages with elevated page_mapcount Mel Gorman
2013-08-08 14:00 ` [PATCH 24/27] sched: Remove check that skips small VMAs Mel Gorman
2013-08-08 14:00 ` [PATCH 25/27] sched: Set preferred NUMA node based on number of private faults Mel Gorman
2013-08-08 14:00 ` [PATCH 26/27] sched: Avoid overloading CPUs on a preferred NUMA node Mel Gorman
2013-08-08 14:00 ` [PATCH 27/27] sched: Retry migration of tasks to CPU on a preferred node Mel Gorman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1375970439-5111-20-git-send-email-mgorman@suse.de \
--to=mgorman@suse.de \
--cc=a.p.zijlstra@chello.nl \
--cc=aarcange@redhat.com \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@kernel.org \
--cc=riel@redhat.com \
--cc=srikar@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox