On Mon, Dec 05, 2016 at 03:54:46AM -0000, zfnoctis(a)gmail.com wrote:
I've created some flamegraphs of sssd_be, hovering your mouse
over the elements should show more information.
This is of sssd_be while running "id <domain user>" with the caches
completely flushed: http://svgshare.com/i/MJ.svg
This is of sssd_be while running "sudo -l" as a domain user with sudo
Clearly there are some symbols missing, but I wasn't sure how to resolve this. If
someone could point me to the package(s) needed to fix this, I'd be happy to rerun
First, sorry for not following up sooner, but there was quite a bit of
different new cases and bugs coming in internally last week, so the
sssd-users list responses are a bit delayed. But some quick thoughts on
the systemtap output and the flame graphs:
1) I think it would be nice (and this is a work for us)
to decorate the paths in sssd_be a bit more with systemtap probes
because there the probes just indicate that sssd started parsing
entries which takes a long time, but we need to break down that
part better into smaller parts to see which exact part of code is
2) Thank you very much for the flame graphs. I'm also a fan of
Brendan Gregg's work :-) Could you tell us how exactly did you
generate those? And to resolve the missing symbols, normally
debuginfo-install sssd should be enough. If you already did that,
maybe 'dnf --enablerepo=\*debuginfo upgrade' would sync the
debuginfo packages in sync with the non-debuginfo ones.
btw especially the flame graphs that captures the sudo output IMO
correlatest with the theory that parsing the entries we receive from
LDAP should be optimized, because the strcasecmp() function appears so
often in the flame graph and I suspect this is coming from us finding
the attributes and the values we are interested in.
I will try to find a bit more time this week to follow up (or ask
some other developer :-) and decorate the hot pats with more systemtap
Thank you for working on us on investigating the performance.