lkml.org 
[lkml]   [2001]   [Nov]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: printk kernel logging for router
On Fri, Nov 09, 2001 at 03:41:17PM +2400, william fitzgerald wrote:
> hi all,
> linux newbie here.

You might be interested in the kernelnewbies.org website, mailinglist,
and IRC channel.

> i need to know some information in regard to
> logging with printk statements.
>
> my plan is to monitor the performance of a linux
> router.i'm adding printk statements to the
> kernel to every function that is called by
> forwarding packets and in that way find precisely
> where a packet or packets get lost.
>
> this is still in progress.

Don't be surprised if all that printing will degrade the performance of
your router.

> when i finally get all my printk statements in, i
> want to be able to flood my router on my own mini
> network.(router running on a p133 using
> redhat7.1)
>
> my understanding of printk is that each time it
> is encountered it is written to disk.so for a lot
> of packets there will be alot of writes,
> therefore slowing the system and producing false
> results.

Printk doesn't write to disk, syslogd does.

> so how to i buffer or record the printk
> statements and print them to disk after my
> packets have gone through the router?
>
> do i edit the printk.c file and change the
> line:
>
> static char buf[1024];
>
> and increase the size of the array?
> or do i edit the klogd.c program and change
> something in there?

Change /etc/syslogd.conf. Put all kernel messages into a separate
logging file and put a '-' before the log file name so syslogd will not
sync the file after each write. See man syslogd, klogd, syslog.conf


Erik

--
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Faculty
of Information Technology and Systems, Delft University of Technology,
PO BOX 5031, 2600 GA Delft, The Netherlands Phone: +31-15-2783635
Fax: +31-15-2781843 Email: J.A.K.Mouw@its.tudelft.nl
WWW: http://www-ict.its.tudelft.nl/~erik/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:13    [W:0.046 / U:2.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site