2002-10-14 14:30:10

by Roy Sigurd Karlsbakk

[permalink] [raw]
Subject: cdrom_sysctl_register uses LOTS of CPU, and no cdrom is attached (2.4.20-pre10)

hi

I have these server nodes, doing video streaming.
and
running a server benchmark with 20 concurrent client connections. hardware is
4 IDE drives. kernel is 2.4.20-pre10 + ext3 O_DIRECT support. filesystem is
ext3.

The only system call that seems to eat any system time of importance is
'cdrom_sysctl_register'

problem is: there is no cdrom on the system!

attached is the .config and these three readprofile output files (pro[123]).
see time to see the interval they have been created in

bash-2.05# ls -l pro[1-3]
-rw-r--r-- 1 root root 13965 Jan 29 00:05 pro1
-rw-r--r-- 1 root root 14193 Jan 29 00:06 pro2
-rw-r--r-- 1 root root 15162 Jan 29 00:09 pro3

roy

--
Roy Sigurd Karlsbakk, Datavaktmester
ProntoTV AS - http://www.pronto.tv/
Tel: +47 9801 3356

Computers are like air conditioners.
They stop working when you open Windows.


Attachments:
pro1 (13.64 kB)
pro2 (13.86 kB)
pro3 (14.81 kB)
.config (19.29 kB)
Download all attachments

2002-10-15 05:14:36

by Zwane Mwaikambo

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Subject: Re: cdrom_sysctl_register uses LOTS of CPU, and no cdrom is attached (2.4.20-pre10)

On Mon, 14 Oct 2002, Roy Sigurd Karlsbakk wrote:

> attached is the .config and these three readprofile output files (pro[123]).
> see time to see the interval they have been created in

These look like bungled up profiles of the magnitude that even i couldn't
conjure up ;)

Zwane

PS: If not, my sincerest apologies...

--
function.linuxpower.ca


2002-10-15 07:39:51

by Roy Sigurd Karlsbakk

[permalink] [raw]
Subject: Re: cdrom_sysctl_register uses LOTS of CPU, and no cdrom is attached (2.4.20-pre10)

On Tuesday 15 October 2002 07:07, Zwane Mwaikambo wrote:
> On Mon, 14 Oct 2002, Roy Sigurd Karlsbakk wrote:
> > attached is the .config and these three readprofile output files
> > (pro[123]). see time to see the interval they have been created in
>
> These look like bungled up profiles of the magnitude that even i couldn't
> conjure up ;)

excuse me?
made a new one now.

why is cdrom_sysctl_register using all that cpu??? I mean - it's got nothing
there to do!

--
Roy Sigurd Karlsbakk, Datavaktmester
ProntoTV AS - http://www.pronto.tv/
Tel: +47 9801 3356

Computers are like air conditioners.
They stop working when you open Windows.


Attachments:
pro4 (19.15 kB)

2002-10-15 09:36:45

by Jens Axboe

[permalink] [raw]
Subject: Re: cdrom_sysctl_register uses LOTS of CPU, and no cdrom is attached (2.4.20-pre10)

On Tue, Oct 15 2002, Roy Sigurd Karlsbakk wrote:
> On Tuesday 15 October 2002 07:07, Zwane Mwaikambo wrote:
> > On Mon, 14 Oct 2002, Roy Sigurd Karlsbakk wrote:
> > > attached is the .config and these three readprofile output files
> > > (pro[123]). see time to see the interval they have been created in
> >
> > These look like bungled up profiles of the magnitude that even i couldn't
> > conjure up ;)
>
> excuse me?
> made a new one now.
>
> why is cdrom_sysctl_register using all that cpu??? I mean - it's got nothing
> there to do!

come on, the profile data is obvious bogus. take a look at
cdrom_sysctl_register(), for chrissake.

--
Jens Axboe