From: Jeffrey 'jf' Lim <jfs.world@...>
Date: 2007-09-05T12:38:41+09:00
Subject: Re: Ruby is much slower on linux when compiled with --enable-pthread?

On 9/4/07, Adam Kramer <akramer@google.com> wrote:
> Hi,
>
> I was seeing significant performance differences between ruby 1.8.4 on
> an old distribution and a newer one. I spent some hours ... <snip>
>

I would be curious about this - are you talking about between ubuntu
6.06, and a newer version of ubuntu?


>
> It appears that when compiled with --enable-pthread ruby will call
> sigprocmask MANY MANY more times than without. You can verify this
> with strace -c:
> $ strace -c ruby -e '1.upto(100000) {|i| i.to_s}'
> % time     seconds  usecs/call     calls    errors syscall
> ------ ----------- ----------- --------- --------- ----------------
> 100.00    0.000655           0    200006           sigprocmask
>
> Yeah - it called sigprocmask over 200,000 times during that 100,000
> iteration loop.
>

same here - ubuntu 7.04 64-bit, ruby 1.8.6 -

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
100.00    0.002105           0    200009           rt_sigprocmask

I also see some errors (8, 3, and 7 respectively - and consistently)
on 'open', 'stat', and 'access'. Do you see those as well?


> When compiled with --disable-pthread and running the same command,
> rt_sigprocmask gets called 4 times.
>

:) for me, this is 2 times.


> I also tested on OS X, ruby is compiled with --enable-pthread but
> sigprocmask doesn't get called an inordinate number of times, so this
> may be a linux-only issue.
>

hmm.. what would be the equivalent of 'strace' here?

-jf

--
In the meantime, here is your PSA:
"It's so hard to write a graphics driver that open-sourcing it would not help."
    -- Andrew Fear, Software Product Manager, NVIDIA Corporation
http://kerneltrap.org/node/7228