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From:   Emil Velikov <emil.l.velikov@gmail.com>
Date:   Fri, 21 Apr 2023 12:45:29 +0100
Message-ID: <CACvgo53dP03r1BuxntyyoYjua5k6XPvVhu4iTGqXJq31UMUgxg@mail.gmail.com>
Subject: Re: [PATCH v4 5/6] drm: Add fdinfo memory stats
To:     Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc:     Rob Clark <robdclark@gmail.com>, dri-devel@lists.freedesktop.org,
        linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org,
        Boris Brezillon <boris.brezillon@collabora.com>,
        Christopher Healy <healych@amazon.com>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Clark <robdclark@chromium.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Jonathan Corbet <corbet@lwn.net>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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On Fri, 21 Apr 2023 at 12:23, Tvrtko Ursulin
<tvrtko.ursulin@linux.intel.com> wrote:

> On 21/04/2023 11:26, Emil Velikov wrote:
> > On Wed, 12 Apr 2023 at 23:43, Rob Clark <robdclark@gmail.com> wrote:
> >
> >> +/**
> >> + * enum drm_gem_object_status - bitmask of object state for fdinfo reporting
> >> + * @DRM_GEM_OBJECT_RESIDENT: object is resident in memory (ie. not unpinned)
> >> + * @DRM_GEM_OBJECT_PURGEABLE: object marked as purgeable by userspace
> >> + *
> >> + * Bitmask of status used for fdinfo memory stats, see &drm_gem_object_funcs.status
> >> + * and drm_show_fdinfo().  Note that an object can DRM_GEM_OBJECT_PURGEABLE if
> >> + * it still active or not resident, in which case drm_show_fdinfo() will not
> >
> > nit: s/can/can be/;s/if it still/if it is still/
> >
> >> + * account for it as purgeable.  So drivers do not need to check if the buffer
> >> + * is idle and resident to return this bit.  (Ie. userspace can mark a buffer
> >> + * as purgeable even while it is still busy on the GPU.. it does not _actually_
> >> + * become puregeable until it becomes idle.  The status gem object func does
> >
> > nit: s/puregeable/purgeable/
> >
> >
> > I think we want a similar note in the drm-usage-stats.rst file.
> >
> > With the above the whole series is:
> > Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
>
> Have you maybe noticed my slightly alternative proposal? (*) I am not a
> fan of putting this flavour of accounting into the core with no way to
> opt out. I think it leaves no option but to add more keys in the future
> for any driver which will not be happy with the core accounting.
>
> *) https://patchwork.freedesktop.org/series/116581/
>

Indeed I saw it. Not a fan of it, I'm afraid.

> > Fwiw: Keeping the i915 patch as part of this series would be great.
> > Sure i915_drm_client->id becomes dead code, but it's a piece one can
> > live with for a release or two. Then again it's not my call to make.
>
> Rob can take the i915 patch from my RFC too.
>

Indeed.

-Emil