lkml.org 
[lkml]   [2013]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:sched/core] sched/numa: Take false sharing into account when adapting scan rate
Commit-ID:  3e6a9418cf05638b103e34f5d13be0321872e623
Gitweb: http://git.kernel.org/tip/3e6a9418cf05638b103e34f5d13be0321872e623
Author: Mel Gorman <mgorman@suse.de>
AuthorDate: Mon, 7 Oct 2013 11:29:35 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 9 Oct 2013 14:48:14 +0200

sched/numa: Take false sharing into account when adapting scan rate

Scan rate is altered based on whether shared/private faults dominated.
task_numa_group() may detect false sharing but that information is not
taken into account when adapting the scan rate. Take it into account.

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/1381141781-10992-58-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/fair.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 222c2d0..d26a16e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1381,7 +1381,8 @@ static void double_lock(spinlock_t *l1, spinlock_t *l2)
spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
}

-static void task_numa_group(struct task_struct *p, int cpupid, int flags)
+static void task_numa_group(struct task_struct *p, int cpupid, int flags,
+ int *priv)
{
struct numa_group *grp, *my_grp;
struct task_struct *tsk;
@@ -1447,6 +1448,9 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags)
if (flags & TNF_SHARED)
join = true;

+ /* Update priv based on whether false sharing was detected */
+ *priv = !join;
+
if (join && !get_numa_group(grp))
join = false;

@@ -1545,7 +1549,7 @@ void task_numa_fault(int last_cpupid, int node, int pages, int flags)
} else {
priv = cpupid_match_pid(p, last_cpupid);
if (!priv && !(flags & TNF_NO_GROUP))
- task_numa_group(p, last_cpupid, flags);
+ task_numa_group(p, last_cpupid, flags, &priv);
}

/*

\
 
 \ /
  Last update: 2013-10-09 20:21    [W:0.493 / U:5.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site