linux-kernel - [PATCH] sched: fix constructing the span cpu mask of sched domain

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 for Android: free password hash cracker in your pocket

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

Date:	Thu, 5 May 2011 20:53:20 +0800
From:	Hillf Danton <dhillf@...il.com>
To:	LKML <linux-kernel@...r.kernel.org>
Cc:	Ingo Molnar <mingo@...e.hu>, Peter Zijlstra <peterz@...radead.org>,
	Mike Galbraith <efault@....de>,
	Yong Zhang <yong.zhang0@...il.com>
Subject: [PATCH] sched: fix constructing the span cpu mask of sched domain

For a given node, when constructing the cpumask for its sched_domain
to span, if there is no best node available after searching, further
efforts could be saved, based on small change in the return value of
find_next_best_node().

Signed-off-by: Hillf Danton <dhillf@...il.com>
---

--- a/kernel/sched.c	2011-04-27 11:48:50.000000000 +0800
+++ b/kernel/sched.c	2011-05-05 20:44:52.000000000 +0800
@@ -6787,7 +6787,7 @@ init_sched_build_groups(const struct cpu
  */
 static int find_next_best_node(int node, nodemask_t *used_nodes)
 {
-	int i, n, val, min_val, best_node = 0;
+	int i, n, val, min_val, best_node = -1;

 	min_val = INT_MAX;

@@ -6811,7 +6811,8 @@ static int find_next_best_node(int node,
 		}
 	}

-	node_set(best_node, *used_nodes);
+	if (best_node != -1)
+		node_set(best_node, *used_nodes);
 	return best_node;
 }

@@ -6837,7 +6838,8 @@ static void sched_domain_node_span(int n

 	for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
 		int next_node = find_next_best_node(node, &used_nodes);
-
+		if (next_node < 0)
+			break;
 		cpumask_or(span, span, cpumask_of_node(next_node));
 	}
 }
--
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/