2018-01-11 18:29:58

by Laura Abbott

[permalink] [raw]
Subject: Re: 答复: 答复: [PATCH] ION: Sys_heap: fix the incorrect pool->gfp_mask setting

On 01/10/2018 06:06 PM, Zengtao (B) wrote:
>> -----?ʼ?ԭ??-----
>> ??????: Laura Abbott [mailto:[email protected]]
>> ????ʱ??: 2018??1??11?? 8:01
>> ?ռ???: Zengtao (B) <[email protected]>; Dan Carpenter
>> <[email protected]>; Chenfeng (puck) <[email protected]>
>> ????: [email protected]; [email protected];
>> [email protected]; [email protected]; [email protected];
>> [email protected]; [email protected]
>> ????: Re: ????: [PATCH] ION: Sys_heap: fix the incorrect pool->gfp_mask
>> setting
>>
>> On 01/09/2018 04:06 AM, Zengtao (B) wrote:
>>>> -----?ʼ?ԭ??-----
>>>> ??????: Dan Carpenter [mailto:[email protected]]
>>>> ????ʱ??: 2018??1??9?? 17:14
>>>> ?ռ???: Chenfeng (puck) <[email protected]>
>>>> ????: Zengtao (B) <[email protected]>; [email protected];
>>>> [email protected]; [email protected];
>>>> [email protected]; [email protected]; [email protected];
>>>> [email protected]; [email protected]
>>>> ????: Re: [PATCH] ION: Sys_heap: fix the incorrect pool->gfp_mask
>>>> setting
>>>>
>>>> On Tue, Jan 09, 2018 at 11:30:09AM +0800, Chen Feng wrote:
>>>>>
>>>>>
>>>>> On 2018/1/9 18:43, Zeng Tao wrote:
>>>>>> This issue is introduced by the commit <e7f63771b60e> ("ION: Sys_heap:
>>>>>> Add cached pool to spead up cached buffer alloc"),
>>>>
>>>> Use the Fixes tag.
>>>>
>>>> Fixes: e7f63771b60e ("ION: Sys_heap: Add cached pool to spead up
>>>> cached buffer alloc")
>>>>
>>> Agree, thanks.
>>>
>>
>> If you're going to be fixing this, it would be good to fix the other problems
>> pointed out (stop with the #define of the flags).
>>
> It is OK, I will fix in the new version fix.
>
> And to make the code more explicit, I have to choices of fixes:
> Choice 1:
> if (orders[i] > 4)
> gfp_flags = high_order_gfp_flags;
> else
> gfp_flags = low_order_gfp_flags;
> Choice 2:
> gfp_flags = (orders[i] > 4) ? high_order_gfp_flags : low_order_gfp_flags;
>

I prefer #1, but please make sure you are following the
suggestions in https://marc.info/?l=linux-kernel&m=151518104214191&w=2

> Any suggestion ?
>
>
> BTW, I found another problem related:
> Currently the order 4 and order 0 allocation flag haven't got the __GFP_NOWARN set,
> if the order 4 allocation failed but the allocation of order 0 success, it will print warning
> message which is useless.
>
> Of course, this is not related to this fix, but this is what I have met when test this fix.
>

Yes, go ahead and fix that in a separate patch too.

> Thanks
> Zengtao
>

Thanks,
Laura