Determining kernel ring buffer size

jsteffe · 03-06-2007, 11:28 PM

I know that you can use "dmesg" to resize the kernel ring buffer.

What I'd like to know is how to determine what the current size is. Something similar to "cat /proc/meminfo".

Please let me know.

Thanks,

John

Quigi · 03-07-2007, 04:00 PM

Quote:

Originally Posted by jsteffe

I know that you can use "dmesg" to resize the kernel ring buffer.

You cannot resize the ring buffer. It's compiled into the kernel. Googling for your question took me to the following lines from the kernel source printk.c, which seem relevant:

Code:

#define __LOG_BUF_LEN   (1 << CONFIG_LOG_BUF_SHIFT)
static char __log_buf[__LOG_BUF_LEN];
static int log_buf_len = __LOG_BUF_LEN;

So CONFIG_LOG_BUF_SHIFT is the base-2 logarithm of the size.

Quote:

What I'd like to know is how to determine what the current size is. Something similar to "cat /proc/meminfo".

zgrep LOG_BUF_SHIFT /proc/config.gz