linux-kernel - [PATCH] sched,numa: always try to migrate to preferred node at task_numa

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140604163315.1dbc7b56@cuia.bos.redhat.com>
Date:	Wed, 4 Jun 2014 16:33:15 -0400
From:	Rik van Riel <riel@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	peterz@...radead.org, mgorman@...e.de, mingo@...nel.org
Subject: [PATCH] sched,numa: always try to migrate to preferred node at
 task_numa_placement time

It is possible that at task_numa_placement time, the task's
numa_preferred_nid does not change, but the task is not
actually running on the preferred node at the time.

In that case, we still want to attempt migration to the
preferred node.

Signed-off-by: Rik van Riel <riel@...hat.com>
---
 kernel/sched/fair.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0fdb96d..708c6a9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1575,11 +1575,13 @@ static void task_numa_placement(struct task_struct *p)
 		spin_unlock_irq(group_lock);
 	}
 
-	/* Preferred node as the node with the most faults */
-	if (max_faults && max_nid != p->numa_preferred_nid) {
-		/* Update the preferred nid and migrate task if possible */
-		sched_setnuma(p, max_nid);
-		numa_migrate_preferred(p);
+	if (max_faults) {
+		/* Set the new preferred node */
+		if (max_nid != p->numa_preferred_nid)
+			sched_setnuma(p, max_nid);
+
+		if (task_node(p) != p->numa_preferred_nid)
+			numa_migrate_preferred(p);
 	}
 }
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/