On 18/05/2021 10:16, Daniel Stone wrote:> Hi,
>
> On Tue, 18 May 2021 at 10:09, Tvrtko Ursulin
> <tvrtko.ursulin at linux.intel.com> wrote:
>> I was just wondering if stat(2) and a chrdev major check would be a
>> solid criteria to more efficiently (compared to parsing the text
>> content) detect drm files while walking procfs.
>
> Maybe I'm missing something, but is the per-PID walk actually a
> measurable performance issue rather than just a bit unpleasant?
Per pid and per each open fd.
As said in the other thread what bothers me a bit in this scheme is that
the cost of obtaining GPU usage scales based on non-GPU criteria.
For use case of a top-like tool which shows all processes this is a
smaller additional cost, but then for a gpu-top like tool it is somewhat
higher.
Regards,
Tvrtko