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Message-ID: <5b6d3e7f-c638-fdc7-5080-44d34abed610@ideasonboard.com>
Date:   Thu, 17 Feb 2022 14:46:00 +0200
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Subject: Re: [PATCH 3/3] drm: omapdrm: Do no allocate non-scanout GEMs through
 DMM/TILER
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To:     Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>, tomba@kernel.org,
        airlied@linux.ie, daniel@ffwll.ch
Cc:     dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        linux-omap@vger.kernel.org, merlijn@wizzup.org, tony@atomide.com
References: <1642587791-13222-1-git-send-email-ivo.g.dimitrov.75@gmail.com>
 <1642587791-13222-4-git-send-email-ivo.g.dimitrov.75@gmail.com>
From:   Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
In-Reply-To: <1642587791-13222-4-git-send-email-ivo.g.dimitrov.75@gmail.com>
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Hi,

On 19/01/2022 12:23, Ivaylo Dimitrov wrote:
> On devices with DMM, all allocations are done through either DMM or TILER.
> DMM/TILER being a limited resource means that such allocations will start
> to fail before actual free memory is exhausted. What is even worse is that
> with time DMM/TILER space gets fragmented to the point that even if we have
> enough free DMM/TILER space and free memory, allocation fails because there
> is no big enough free block in DMM/TILER space.
> 
> Such failures can be easily observed with OMAP xorg DDX, for example -
> starting few GUI applications (so buffers for their windows are allocated)
> and then rotating landscape<->portrait while closing and opening new
> windows soon results in allocation failures.
> 
> Fix that by mapping buffers through DMM/TILER only when really needed,
> like, for scanout buffers.

Doesn't this break users that get a buffer from omapdrm and expect it to 
be contiguous?

  Tomi