On Thursday, September 16, 2010, Tejun Heo wrote: > Hello, Rafael. > > On 09/15/2010 09:56 PM, Rafael J. Wysocki wrote: > > I'm not sure about that WQ_RESCUER thing. Can you please tell me what > > exactly it is for? > > It's to guarantee forward progress for workqueues which process work > items which may be used to reclaim memory. It reserves a rescue > worker thread to be used under memory pressure. I finished workqueue > documentation a few days ago and sent pull request to Linus. > > http://git.kernel.org/?p=linux/kernel/git/tj/wq.git;a=blob;f=Documentation/workqueue.txt;h=e4498a2872c37a0b3b156ddc7ad7135d030d224d;hb=c54fce6eff197d9c57c97afbf6c9722ce434fc8f > > So, for pm_wq, there's no reason to use WQ_RESUER. > alloc_workqueue("pm", WQ_FREEZEABLE, 0) should do it. Great, thanks! > Thanks for doing it. No big deal. Actually I should thank you for making it possible to use freezable workqueues that are not singlethread. :-) Updated patch follows. Thanks, Rafael --- From: Rafael J. Wysocki <rjw@xxxxxxx> Subject: PM / Runtime: Use alloc_workqueue() for creating the PM workqueue Although we need the PM workqueue to be freezable, we don't need it to be singlethread. Also, the number of concurrent work items running on a single CPU need not be constrained. For these reasons use alloc_workqueue() directly, with suitable arguments, instead of create_freezeable_workqueue(), to create the runtime PM workqueue. Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- kernel/power/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6/kernel/power/main.c =================================================================== --- linux-2.6.orig/kernel/power/main.c +++ linux-2.6/kernel/power/main.c @@ -308,7 +308,7 @@ EXPORT_SYMBOL_GPL(pm_wq); static int __init pm_start_workqueue(void) { - pm_wq = create_freezeable_workqueue("pm"); + pm_wq = alloc_workqueue("pm", WQ_FREEZEABLE, 0); return pm_wq ? 0 : -ENOMEM; } _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
