linux-kernel - [PATCH 2/5] workqueue: change value of lcpu in queue_delayed_work

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

Date:	Tue, 14 Aug 2012 01:17:49 +0900
From:	Joonsoo Kim <js1304@...il.com>
To:	Tejun Heo <tj@...nel.org>
Cc:	linux-kernel@...r.kernel.org, Joonsoo Kim <js1304@...il.com>
Subject: [PATCH 2/5] workqueue: change value of lcpu in queue_delayed_work_on()

We assign cpu id into work struct in queue_delayed_work_on().
In current implementation, when work is come in first time,
current running cpu id is assigned.
If we do queue_delayed_work_on() with CPU A on CPU B,
__queue_work() invoked in delayed_work_timer_fn() go into sub-optimal path
in case of WQ_NON_REENTRANT.
Change it to cpu argument is prevent to go into sub-optimal path.

Signed-off-by: Joonsoo Kim <js1304@...il.com>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 188eef8..bc5c5e1 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1158,6 +1158,8 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 
 			if (gcwq && gcwq->cpu != WORK_CPU_UNBOUND)
 				lcpu = gcwq->cpu;
+			else if (cpu >= 0)
+				lcpu = cpu;
 			else
 				lcpu = raw_smp_processor_id();
 		} else
-- 
1.7.9.5

--
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/