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Date: Wed, 27 Jul 2011 00:48:50 +0000
From: Alexander Best <arundel@freebsd.org>
To: Matthias Andree <matthias.andree@gmx.de>
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Cc: Norberto Lopes <nlopes.ml@gmail.com>, Adrian Chadd <adrian@freebsd.org>,
	freebsd-current@freebsd.org
Subject: Re: chromium port causing massive I/O faults
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On Mon Jul 25 11, Matthias Andree wrote:
> Am 25.07.2011 09:21, schrieb Alexander Best:
> > On Mon Jul 25 11, Adrian Chadd wrote:
> >> Is it perhaps doing disk IO using mmap?
> > 
> > how can i check, whether that's the case or not?
> 
> Use truss(1) for instance.
> 
> However, unless there are *practical* problems, a high number of page
> faults is not an indication for problems.  Although it may sound scary,
> page faults are a feature of the memory management.

unfortunately truss(1) is crashing chromium :( i opened up a new thread
reagarding this issue on freebsd-current@.

another thing i noticed is the increase in system calls caused by chromium.
let's have a look at hub.freebsd.org:

uptime = 149 days

and 'vmstat -s' reports:

2168697753 cpu context switches
2266220366 device interrupts
2902880931 software interrupts
3779075897 traps
902107847 system calls

now on my box:

uptime = 2 days

and 'vmstat -s' reports:

1155995386 cpu context switches
164577882 device interrupts
189456976 software interrupts
137007580 traps
2178434582 system calls

i ran the following command twice. first time without running chromium and the
second time with chromium running:

otaku% vmstat -s|grep "system calls"; sleep 1; vmstat -s|grep "system calls"
2178187850 system calls
2178189739 system calls

otaku% vmstat -s|grep "system calls"; sleep 1; vmstat -s|grep "system calls"
2177998835 system calls
2178022003 system calls

so it's 2k/sec vs. 23k/sec!!!!

cheers.
alex