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Message-ID: <49fe9ecf-b1bd-a21b-8d8c-e4a33e3fa821@collabora.com>
Date:   Fri, 29 Jul 2022 18:27:19 +0300
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Subject: Re: [PATCH v3 09/15] drm/gem: Add LRU/shrinker helper
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To:     Rob Clark <robdclark@gmail.com>, dri-devel@lists.freedesktop.org
Cc:     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>
 <20220726175043.1027731-10-robdclark@gmail.com>
From:   Dmitry Osipenko <dmitry.osipenko@collabora.com>
In-Reply-To: <20220726175043.1027731-10-robdclark@gmail.com>
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On 7/26/22 20:50, Rob Clark wrote:
> +/**
> + * drm_gem_lru_move_tail_locked - move the object to the tail of the LRU
> + *
> + * If the object is already in this LRU it will be moved to the
> + * tail.  Otherwise it will be removed from whichever other LRU
> + * it is in (if any) and moved into this LRU.
> + *
> + * Call with LRU lock held.
> + *
> + * @lru: The LRU to move the object into.
> + * @obj: The GEM object to move into this LRU
> + */
> +void
> +drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj)
> +{
> +	lockdep_assert_held_once(lru->lock);
> +
> +	if (obj->lru)
> +		lru_remove(obj);

The obj->lru also needs to be locked if lru != obj->lru, isn't it? And
then we should add lockdep_assert_held_once(obj->lru->lock).

-- 
Best regards,
Dmitry