Messages in this thread |  | | Date | Thu, 8 Nov 2001 17:25:48 +0100 | From | Erik Mouw <> | Subject | Re: printk kernel logging for router |
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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/
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