On Mon, 13 Mar 2000, Mike A. Harris wrote:
> On Fri, 10 Mar 2000, Richard B. Johnson wrote:
>
> >> This machine is running 2.0.36 compiled with gcc 2.7.2.3, and has
> >> Syslog: syslogd 1.3-3
> >
> >A guess. If you are having the kernel send messages, i.e., you are
> >going through printk(), and the messages are streaming, you are
> >running into the fact that printk() has a fixed-length buffer and
> >just truncates anything that can't fit.
> >
> >This is more-or-less necessary because printk() was designed to
> >print "panic" and such even after memory allocation failed....
>
> Ok, that is acceptable, but how big is this buffer in
> 2.0.36? There seem to be log entries that are much longer than
> the ones that are chopped off, and the part chopped off is
> consistently the *START* of the buffer, not the end. Odd. I
> don't know if the same occurs under 2.2.x or not..
>
The current log buffer is 16384 bytes in length. It's in
../linux/kernel/printk.c. If you are using printk() to log something
that you can't keep up with, you are either logging to a very slow
drive, or you are logging way too much data. printk() was not designed
to be a general-purpose logging device. It's supposed to handle logging
failures while minimizing the resources used so there is a good chance
that it actually gets logged somewhere.
If you are trying to log network activity, you need to use tcpdump
or some write-your-own user space utility.
Cheers,
Dick Johnson
Penguin : Linux version 2.3.41 on an i686 machine (800.63 BogoMips).
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Wed Mar 15 2000 - 21:00:26 EST