linux-kernel - Re: Re: [PATCH v2] PM / Sleep: Use workqueue for user space wakeup sources garbage collector

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Date:	Fri, 3 Jul 2015 14:03:05 +0900
From:	"SungEun Kim(cleaneye.kim@....com)" <cleaneye.kim@....com>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	pavel@....cz, len.brown@...el.com, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: Re: [PATCH v2] PM / Sleep: Use workqueue for user space wakeup
 sources garbage collector

On 2015-07-03 오전 9:15, Rafael J. Wysocki wrote:
> On Wednesday, July 01, 2015 05:28:48 PM SungEun Kim wrote:
>> From: "SungEun Kim" <cleaneye.kim@....com>
>>
>> The synchronous synchronize_rcu in wakeup_source_remove makes user
> process
>> which writes to /sys/kernel/wake_unlock blocked sometimes.
>>
>> For example, when android eventhub tries to release wakelock,
>> this blocking process can occur, and eventhub can't get input event
>> for a while.
>>
>> Using workqueue instead of direct function call at pm_wake_unlock
>> can prevent this unnecessary delay of an user space process.
> 
> The idea is defendable, but the patch is too simple.
> 
> For example, if the garbage collection is in progress, it is not useful
> to start a new one.
> 
> Also the incrementation and clearing of wakelocks_gc_count should be under
> the lock.

Thank you for your advices.
I will correct and amend my patch and then submit v3 patch.

Thank you.
SungEun Kim

> 
> 
> -- 
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
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