Re: Add LWLock blocker(s) information

Hi,

On 2020-08-12 16:47:13 -0700, Peter Geoghegan wrote:
> On Mon, Aug 10, 2020 at 5:41 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
> > Most of the cases where this kind of information really is interesting
> > seem to benefit a lot from having stack information available. That
> > obviously has overhead, so we don't want the cost all the
> > time. The script at
> > https://postgr.es/m/20170622210845.d2hsbqv6rxu2tiye%40alap3.anarazel.de
> > can give you results like e.g.
> > https://anarazel.de/t/2017-06-22/pgsemwait_64_async.svg
>
> It seems to have bitrot. Do you have a more recent version of the script?

Attached. Needed one python3 fix, and to be adapted so it works with
futex based semaphores. Seems to work for both sysv and posix semaphores
now, based a very short test.

sudo python3 ./pgsemwait.py -x /home/andres/build/postgres/dev-optimize/vpath/src/backend/postgres -f 3|~/src/flamegraph/flamegraph.pl

Will add a note to the other thread.

Greetings,

Andres Freund