linux-kernel - Re: [PATCH] drivers: base: power: Fix GFP

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Date:   Sat, 16 Dec 2017 13:51:08 +0530
From:   shrikant <shrikant.maurya@...hveda.org>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Pavel Machek <pavel@....cz>, Len Brown <len.brown@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        sunil.m@...hveda.org, karthik@...hveda.org, raghu@...hveda.org
Subject: Re: [PATCH] drivers: base: power: Fix GFP_KERNEL in spinlock context



On Tuesday 12 December 2017 10:25 PM, Rafael J. Wysocki wrote:
> On Tue, Dec 12, 2017 at 2:45 PM,  <shrikant.maurya@...hveda.org> wrote:
>> From: Shrikant Maurya <shrikant.maurya@...hveda.org>
>>
>> As reported by Jia-Ju Bai (https://lkml.org/lkml/2017/12/11/872):
>> API's are using GFP_KERNEL to allocate memory which may sleep.
>>
>> To ensure atomicity such allocations must be avoided in critical
>> sections under spinlock.
> 
> That's right.
> 
> Which is why wakeup_source_create() should never be called under a spinlock.

Yes.

Better approach is, to move the call to device_init_wakeup() before the spinlock.

> 
> Are you aware of any place that happens in the mainline kernel?

No.

> 
> Thanks,
> Rafael
> 

Thank you Rafeal.
-- 
Shrikant
techveda.org