From: Hugh Sasse Staff Elec Eng <hgs@...>
Date: 2005-02-28T19:31:52+09:00
Subject: Re: ruby, solaris, and high cpu load relating to SIGVTALRM

On Mon, 28 Feb 2005, Jim Helm wrote:

> Is anyone else seeing high cpu loads under solaris? When installing

I think I've seen this, ruby processing appearing high up with top.

> gems, during RDoc generation, the cpu load goes to 100%. Even when
> there's no disk I/O.  When I run truss, I get near continuous output
> of:
>
> 12619:  setcontext(0xFFBEC840)
> 12619:      Received signal #28, SIGVTALRM [caught]
> 12619:  lwp_sigmask(SIG_SETMASK, 0x08000000, 0x00000000) = 0xFFBFFEFF
> [0x0000FFFF]

http://groups-beta.google.com/group/comp.lang.ruby/browse_thread/thread/c333cdd2c9793a10/

might be relevant here, or look for SIGVTALRM in 
http://rubygarden.org/ruby/ruby?RubyNews/2005-02-14
which is a shorter URL.


Have you a small example I can use to replicate this? 
truss gem list --local 
doesn't leave SIGVT in the typescript file...
>
> The addresses change on each iteration, of course.
>
> This happens at other times too, but I can reproduce it consistently
> with gem installs (during rdoc gen) or by running 'make install-docs'

Anything "non-destructive" that does this, i.e. which I can run and
leave my system unchanged?

> from the source tree. Is this just a side effect of ruby's built-in
> threading?   Or something quirky about ruby under solaris?

Possibly threading, but I don't know enough about internals to
comment
>
> This happens under Solaris 2.6, 9, and 10, on three different servers
> (all sparc based).

I can try to reproduce this on Solaris 9.

         Hugh