Re: [RFC PATCH 0/5] Introduce /proc/all/ to gather stats from all processes

Eugene Lubarsky
2020-08-13T15:01:30Z

On Wed, 12 Aug 2020 00:51:35 -0700
Andrei Vagin <avagin@gmail.com> wrote:

> Maybe we need resurrect the task_diag series instead of inventing
> another less-effective interface...

I would certainly welcome the resurrection of task_diag - it is clearly
more efficient than this /proc/all/ idea. It would be good to find out
if there's anything in particular that's currently blocking it.

This RFC is mainly meant to check whether such an addition would
be acceptable from an API point of view. It currently has an obvious
performance issue in that seq_file seems to only return one page at a
time so lots of read syscalls are still required. However I may not
have the time to figure out a proposed fix for this by myself.
Regardless, text-based formats can't match the efficiency of task_diag,
but binary ones are also possible.

Best Wishes,
Eugene