Re: [naviserver-devel] tcmalloc and jemalloc results with naviserver

[John B. <jo...@ma...>]

On Jan 5, 2014, at 2:27 PM, Wolfgang Winkler <wol...@di...> wrote:

> I was wondering, why you'll want to have 100 threads, because the number seems a little high to me. So I've just conducted some test on two of our development system.

You're right, 100 is high, but I do use SQL quite a lot, and so long running threads, where the cpu is blocking, waiting for a SQL server response, can generate a lot of pending threads.

I wanted enough threads to be around to handle short running page requests too.

But besides that, it's very odd that tcmalloc had this huge decrease in performance at 100 threads.  It's perhaps not enough of a reason to avoid tcmalloc, but it's a cause to worry, nonetheless.

Gustaf's tests didn't show that same slowdown result, and the big slowdown I have at 100 threads only happens with tcmalloc, not with jemalloc or zippy, with a simple [clock seconds] ADP page.

-john