From: Arnd Bergmann <arnd@arndb•de>
To: linuxppc-dev@ozlabs•org
Cc: Milton Miller <miltonm@bga•com>
Subject: Re: 82xx performance
Date: Thu, 17 Jul 2008 17:47:28 +0200 [thread overview]
Message-ID: <200807171747.28624.arnd@arndb.de> (raw)
In-Reply-To: <DCEAAC0833DD314AB0B58112AD99B93B04B34B71@ismail.innsys.innovsys.com>
On Thursday 17 July 2008, Rune Torgersen wrote:
> Arnd Bergmann wrote:
> > If you can't get it to work, readprofile(1) is a much simpler
> > tool, both in what it can do and what it requires you to do.
>
> One thing that pops out is that handle_mm_fault uses twice as many
> ticks in arch/powerpc.
The other thing I found interesting is that cpu_idle is on the
top of the list in arch/powerpc but does not show up anywhere
in your top arch/ppc samples. This indicates that the system is
waiting for something, e.g. disk I/O for a significant amount
of time.
Seeing more hits in handle_mm_fault suggests that you have
a higher page fault rate. A trivial reason for this might
be that the amount of memory was misdetected in the new
code (maybe broken device tree). What is the content of
/proc/meminfo after a fresh boot?
If it's the same, try running a kernel build with 'time --verbose',
using GNU time instead of the bash builtin time to see how the
page fault rate changed.
Arnd <><
next prev parent reply other threads:[~2008-07-17 15:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-14 16:34 82xx performance Rune Torgersen
2008-07-14 20:44 ` Arnd Bergmann
2008-07-15 14:16 ` Rune Torgersen
2008-07-15 18:25 ` Rune Torgersen
2008-07-15 19:50 ` Arnd Bergmann
2008-07-16 21:08 ` Rune Torgersen
2008-07-16 21:45 ` Arnd Bergmann
2008-07-16 21:53 ` Rune Torgersen
2008-07-16 22:32 ` Arnd Bergmann
2008-07-17 15:12 ` Rune Torgersen
2008-07-17 15:47 ` Arnd Bergmann [this message]
2008-07-17 15:52 ` Rune Torgersen
2008-07-17 18:24 ` Rune Torgersen
2008-07-17 19:43 ` Arnd Bergmann
2008-07-17 19:54 ` Rune Torgersen
2008-07-17 21:32 ` Arnd Bergmann
2008-07-25 20:41 ` Rune Torgersen
2008-07-26 3:47 ` Milton Miller
2008-07-15 15:57 ` Milton Miller
2008-07-15 18:12 ` Rune Torgersen
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