linux-kernel - [patchlet] sched: minor fast-path overhead reduction

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]

Date:	Fri, 17 Oct 2008 15:33:21 +0200
From:	Mike Galbraith <efault@....de>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc:	Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>
Subject: [patchlet] sched: minor fast-path overhead reduction

Greetings,

103638d added a bit of avoidable overhead to the fast-path.

Use sysctl_sched_min_granularity instead of sched_slice() to restrict buddy wakeups.

Signed-off-by: Mike Galbraith <efault@....de>
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 18fd171..6708493 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -747,7 +747,7 @@ pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	struct rq *rq = rq_of(cfs_rq);
 	u64 pair_slice = rq->clock - cfs_rq->pair_start;
 
-	if (!cfs_rq->next || pair_slice > sched_slice(cfs_rq, cfs_rq->next)) {
+	if (!cfs_rq->next || pair_slice > sysctl_sched_min_granularity) {
 		cfs_rq->pair_start = rq->clock;
 		return se;
 	}


--
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/