Jason Thorpe writes:

> On Sun, 20 Feb 2000 12:04:32 +1300 
>  Dave Sainty <dave@dtsp.co.nz> wrote:
> 
>  > Most people have to do this by hand.  Wouldn't it be cool if there was
>  > a small static circular buffer that could be read from kmem/core that
>  > contained the output of ddb....
> 
> We could change db_printf() to also send to msgbuf (DDB uses it for the
> --more-- facility).

That would be cool if there are no issues with accessing msgbuf from
DDB.

I thought perhaps there might be some problems with that (say panic
whilst in the middle of something updating it (from another CPU?)).
With a separate buffer any concurrency problems go away (or "don't
really matter"), and the buffer would only take up space in DDB
kernels.

Oh, the other one was that perhaps the msgbuf text would be of
interest after a panic, but would quickly be lost if mucking around in
DDB.

On the down side, a separate buffer would need a new program to read
it.  Well, I guess an option to dmesg would do....

Cheers,

Dave