Subject: Re: [PATCH] t9501: Skip testing load if we can't detect it

From: Jakub Narebski <[email-masked]>
Date: Sat, 06 Feb 2010 03:22:44 -0800 (PST)

Brian Gernhardt <[email-masked]> writes:

> Currently gitweb only knows how to check for load using /proc/loadavg,
> which isn't available on all systems.  We shouldn't fail the test just
> because we don't know how to check the system load.
> 
> Signed-off-by: Brian Gernhardt <[email-masked]>

NAK.  It is not necessary, and it would be hindrance (one more place
to update) if we are to extend get_loadavg() in gitweb to work without
/proc/loadavg, e.g. via BSD::loadavg module.

Let me explain how it currently works without /proc/loadavg.  

First, load average is by definition non-negative number (>= 0).

Second, the get_loadavg() subroutine is written to be resilent and
robust, and it returns 0 if it can't get load average from system
(which _currently_ means no well-formatted /proc/loadavg file)

Third, the test (as you can see below in context line in quoted diff
below) forces gitweb to go over maximum load by setting $maxload to 0.
This means that regardless of true load, and regardless whether gitweb
can detect system load (remember that if it cant get system load it
returns 0 instead) gitweb would be in "load too high" situation.

> ---
>  t/t9501-gitweb-standalone-http-status.sh |    9 ++++++++-
>  1 files changed, 8 insertions(+), 1 deletions(-)
> 
> diff --git a/t/t9501-gitweb-standalone-http-status.sh b/t/t9501-gitweb-standalone-http-status.sh
> index 7590f10..992d729 100755
> --- a/t/t9501-gitweb-standalone-http-status.sh
> +++ b/t/t9501-gitweb-standalone-http-status.sh
> @@ -115,12 +115,19 @@ test_debug 'cat gitweb.output'
>  # ----------------------------------------------------------------------
>  # load checking
>  
> +if test -e /proc/loadavg
> +then
> +	test_set_prereq PROC_LOADAVG
> +else
> +	say 'skipping load tests (no /proc/loadavg found)'
> +fi
> +
>  # always hit the load limit
>  cat >>gitweb_config.perl <<\EOF
>  our $maxload = 0;
>  EOF
>  
> -test_expect_success 'load checking: load too high (default action)' '
> +test_expect_success PROC_LOADAVG 'load checking: load too high (default action)' '
>  	gitweb_run "p=.git" &&
>  	grep "Status: 503 Service Unavailable" gitweb.headers &&
>  	grep "503 - The load average on the server is too high" gitweb.body
> -- 
> 1.7.0.rc1.141.gd3fd2
> 

-- 
Jakub Narebski
Poland
ShadeHawk on #git