[Freedreno] [PATCH -next] drm/msm/msm_gem_shrinker: fix compile error in can_block()

[Yang Yingliang]

Hi,

On 2022/9/30 4:38, Rob Clark wrote:
> On Thu, Sep 29, 2022 at 4:51 AM Akhil P Oommen <quic_akhilpo at quicinc.com> wrote:
>> On 9/29/2022 3:00 PM, Yang Yingliang wrote:
>>> I got the compile error:
>>>
>>>     drivers/gpu/drm/msm/msm_gem_shrinker.c: In function ‘can_block’:
>>>     drivers/gpu/drm/msm/msm_gem_shrinker.c:29:21: error: ‘__GFP_ATOMIC’ undeclared (first use in this function); did you mean ‘GFP_ATOMIC’?
>>>       if (sc->gfp_mask & __GFP_ATOMIC)
>>>                          ^~~~~~~~~~~~
>>>                          GFP_ATOMIC
>>>     drivers/gpu/drm/msm/msm_gem_shrinker.c:29:21: note: each undeclared identifier is reported only once for each function it appears in
>>>
>>> __GFP_ATOMIC is dropped by commit 6708fe6bec50 ("mm: discard __GFP_ATOMIC").
>>> Use __GFP_HIGH instead.
>>>
>>> Fixes: 025d27239a2f ("drm/msm/gem: Evict active GEM objects when necessary")
>>> Signed-off-by: Yang Yingliang <yangyingliang at huawei.com>
>>> ---
>>>    drivers/gpu/drm/msm/msm_gem_shrinker.c | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
>>> index 58e0513be5f4..6a0de6cdb82b 100644
>>> --- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
>>> +++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
>>> @@ -26,7 +26,7 @@ static bool can_swap(void)
>>>
>>>    static bool can_block(struct shrink_control *sc)
>>>    {
>>> -     if (sc->gfp_mask & __GFP_ATOMIC)
>>> +     if (sc->gfp_mask & __GFP_HIGH)
>>>                return false;
>>>        return current_is_kswapd() || (sc->gfp_mask & __GFP_RECLAIM);
>>>    }
>> Reviewed-by: Akhil P Oommen <quic_akhilpo at quicinc.com>
>>
> Somehow the original patch didn't show up in my inbox, but I've sent this:
>
> https://patchwork.freedesktop.org/series/109255/
When __GFP_ATOMIC is not dropped, if __GFP_KSWAPD_RECLAIM is set,
it allows sleep(can_block() returns true).
In your patch case, if __GFP_KSWAPD_RECLAIM is set but 
__GFP_DIRECT_RECLAIM is
not set, it don't allows sleep(can_blcok() returns false). It's 
different from earlier behavior.

Thanks,
Yang
>
> I guess __GFP_HIGH could also be used to detect GFP_ATOMIC, but
> checking that direct reclaim is ok seems safer (ie. it should always
> be safe to sleep in that case)
>
> BR,
> -R
>
>> -Akhil.
> .