linux-kernel - [patch 3/4] BFS 420: add task state check in ttwu

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>] [day] [month] [year] [list]

Date:	Fri, 25 May 2012 21:35:37 +0800
From:	Hillf Danton <dhillf@...il.com>
To:	LKML <linux-kernel@...r.kernel.org>,
	Hillf Danton <dhillf@...il.com>
Subject: [patch 3/4] BFS 420: add task state check in ttwu

If the given state does not match task, no bother acquiring the global
runqueue lock.

--- a/kernel/sched/bfs.c	Mon May 14 20:50:38 2012
+++ b/kernel/sched/bfs.c	Fri May 25 20:28:00 2012
@@ -1583,6 +1583,8 @@ static bool try_to_wake_up(struct task_s
 	/* This barrier is undocumented, probably for p->state? くそ */
 	smp_wmb();

+	if (!(p->state & state))
+		goto out;
 	/*
 	 * No need to do time_lock_grq as we only need to update the rq clock
 	 * if we activate the task
@@ -1597,14 +1599,14 @@ static bool try_to_wake_up(struct task_s
 	if (task_queued(p) || task_running(p))
 		goto out_running;

-	ttwu_activate(p, rq, wake_flags & WF_SYNC);
+	ttwu_activate(p, rq, !!(wake_flags & WF_SYNC));
 	success = true;

 out_running:
 	ttwu_post_activation(p, rq, success);
 out_unlock:
 	task_grq_unlock(&flags);
-
+out:
 	ttwu_stat(p, cpu, success);

 	put_cpu();
--
--
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/