My weapon of choice there would be oprofile, run something like this under high load and/or when you have a lot of threads active:
opcontrol --init # You'll want a debug kernel # For example, the Ubuntu package is linux-image-debug-server opcontrol --setup --vmlinux=/boot/vmlinux-2.6.24-server opcontrol --reset ; opcontrol --start ; sleep 60 ; opcontrol --stop opreport -r -l (with and without -l) At the bottom you'll see the most costly calls and any obvious stand- outs. My runs on Varnish show an interestingly high amount of timezone stuff in libc, but no real low-hanging fruit. -- kb On Sep 10, 2009, at 1:22 AM, Václav Bílek wrote: > > >> >> I guess my point is that certain use cases (some valid, some not, >> some >> involving bad pthread libraries in distributions (lots of them out >> there!)) > > How can I identify if our pthread libraries are in trouble? _______________________________________________ varnish-misc mailing list [email protected] http://projects.linpro.no/mailman/listinfo/varnish-misc
