Re: [PATCH 0/24] kernel: add a netlink interface to get information about processes (v2)

[Arnaldo Carvalho de Melo <acme-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

Em Tue, Jul 07, 2015 at 06:43:46PM +0300, Andrew Vagin escreveu:
> On Mon, Jul 06, 2015 at 10:10:32AM -0700, Andy Lutomirski wrote:
> > On Mon, Jul 6, 2015 at 1:47 AM, Andrey Vagin <avagin-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org> wrote:
> > Would it make more sense to have a new syscall instead?  You could
> > even still use nlattr formatting for the syscall results.
> 
> Andy, thank you for the feedback. I got your points. I need time to
> think about them. I suppose that a new syscall can be more suitable in
> this case, and I need time to form a vision of it. If you have any ideas
> or thoughts, I would be glad to know about them.

If a new syscall would indeed be better for this, then using
sys_perf_event_open and on one of the perf_event_attr flip a bit to ask
for those PERF_RECORD_{COMM,FORK,PERF_RECORD_MMAP2, etc} to be generated
in the perf buffer could make it reuse all the userspace tooling, with
really minimal change: flip the bit, don't synthesize it from /proc.

- Arnaldo