Re: [PATCH 1/8] PM: Add suspend block api.

Tejun Heo
2010-04-30T04:24:43Z

Hello,

On 04/29/2010 11:16 PM, Rafael J. Wysocki wrote:
>>> Also, we already have one PM workqueue. It is used for runtime PM, but I guess
>>> it may be used just as well for the opportunistic suspend. It is freezable,
>>> but would it hurt?
>>
>> No, it works, the freezable flag is just ignored when I call
>> pm_suspend and I don't run anything else on the workqueue while
>> threads are frozen. It does need to be a single threaded workqueue
>> though, so make sure you don't just change that.
>
> Freezable workqueues have to be singlethread or else there will be unfixable
> races, so you can safely assume things will stay as they are in this respect.

Rafael, can you elaborate a bit more on this? Just in case I missed
something while doing cmwq as it currently doesn't have such limit.

Thanks.

--
tejun