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Message-ID: <733f5d3f-293e-f951-a00b-fcd3052f68e7@collabora.com>
Date:   Mon, 1 Aug 2022 23:13:44 +0300
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Subject: Re: [PATCH v3 09/15] drm/gem: Add LRU/shrinker helper
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From:   Dmitry Osipenko <dmitry.osipenko@collabora.com>
To:     Rob Clark <robdclark@gmail.com>
Cc:     dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org,
        linux-arm-msm@vger.kernel.org, Rob Clark <robdclark@chromium.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        David Airlie <airlied@linux.ie>,
        open list <linux-kernel@vger.kernel.org>
References: <20220726175043.1027731-1-robdclark@gmail.com>
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 <def8e47c-067e-0841-4ae4-1eb90244cd50@collabora.com>
 <CAF6AEGtV4GY6=PmQh0wrKxjxk_baRCzOo=s=Uz-uKBNEn7SBBg@mail.gmail.com>
 <6b35b912-68e5-e722-0b5a-0f7bd06c22c2@collabora.com>
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On 8/1/22 23:11, Dmitry Osipenko wrote:
> On 8/1/22 23:00, Rob Clark wrote:
>> On Mon, Aug 1, 2022 at 12:41 PM Dmitry Osipenko
>> <dmitry.osipenko@collabora.com> wrote:
>>>
>>> On 7/26/22 20:50, Rob Clark wrote:
>>>> +/**
>>>> + * drm_gem_lru_remove - remove object from whatever LRU it is in
>>>> + *
>>>> + * If the object is currently in any LRU, remove it.
>>>> + *
>>>> + * @obj: The GEM object to remove from current LRU
>>>> + */
>>>> +void
>>>> +drm_gem_lru_remove(struct drm_gem_object *obj)
>>>> +{
>>>> +     struct drm_gem_lru *lru = obj->lru;
>>>> +
>>>> +     if (!lru)
>>>> +             return;
>>>> +
>>>> +     mutex_lock(lru->lock);
>>>> +     lru_remove(obj);
>>>> +     mutex_unlock(lru->lock);
>>>> +}
>>>> +EXPORT_SYMBOL(drm_gem_lru_remove);
>>>
>>> I made a preliminary port of the DRM-SHMEM shrinker on top of the the
>>> latest version of dma-buf locking convention and yours LRU patches. It
>>> all works good, the only thing that is missing for the DRM-SHMEM
>>> shrinker is the drm_gem_lru_remove_locked().
>>>
>>> What about to add a locked variant of drm_gem_lru_remove()?
>>
>> Sounds fine to me.. the only reason it didn't exist yet was because it
>> wasn't needed yet..
> 
> There is no use for the drm_gem_lru_move_tail_locked() as well, you're
> not using it in the MSM driver. Hence I thought it might be good to add
> the drm_gem_lru_remove_locked(), or maybe the
> drm_gem_lru_move_tail_locked() should be dropped then?
> 
>> I can respin w/ an addition of a _locked() version, or you can add it
>> on top in your patchset.  Either is fine by me
> 
> The either option is fine by me too. If you'll keep the unused
> drm_gem_lru_move_tail_locked(), then will be nice to add
> drm_gem_lru_remove_locked().
> 

The drm_gem_lru_move_tail_locked() will be needed by DRM-SHMEM shrinker,
BTW.

-- 
Best regards,
Dmitry