Re: [PATCH v8 01/13] tools/libperf: avoid moving of fds at fdarray__filter() call

Jiri Olsa
2020-06-29T19:17:13Z

On Mon, Jun 29, 2020 at 06:11:52PM +0300, Alexey Budankov wrote:

SNIP

> >>
> >> I'm confused, are you talking about file descriptors limit now?
> >> this wont be affected by epoll change.. what do I miss?
> >
> > Currently there is already uname -n limit on the amount of open file descriptors
> > and Perf tool process is affected by that limit.
> >
> > Moving to epoll() will impose one more max_user_watches limit and that can additionally
> > confine Perf applicability even though default value on some machines currently
> > is high enough.
>
> Prior making v9 I would prefer to agree on some design to be implemented in order to
> avoid guessing and redundant reiterating.
>
> Options that I see as good balanced ones are 1) or 5), + non screwing of fds to fix
> staleness of pos(=fdarray__add()).
>
> Are there any thoughts so far?

let's try it and discuss over the code

jirka