Re: [PATCH] udmabuf: vastly increase the size limit per dmabuf

Hi,

Vivek (thanks!) just pulled the patch into drm-misc-next / 
for-linux-next so it should go into 7.3 \o/

On 03.08.26 17:04, Xaver Hugl wrote:
> Oh, nice! I should've checked the list before making a patch :D
>
> Could your commit also be backported to stable? I fear I'll need to
> find ways to work around this or disable the relevant optimizations in
> KWin on older kernels either way, but it would be great if that could
> at least be a very temporary problem.

I'm not sure how realistic that is / how the policies around such 
changes are - there shouldn't be any serious risk of regressions, but 
who knows.

OTOH there are several other options AFAICS:

1. affected distros could backport the patch or set a higher limit via 
kernel command line

2. kwin could try to check the size 
(`/sys/module/udmabuf/parameters/size_limit_mb`) and disallow the code 
path if the required buffer size exceeds it (or just have a fallback in 
place whenever allocation fails)

Arguably having a working fallback path were possible would be good 
style either way - would it be a big effort to do so in kwin?

Best regards

>
> - Xaver

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Robert Mader
Consultant Software Developer

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