dueling (s)printf()'s - what's the cure?

Jeremy Chadwick koitsu at FreeBSD.org
Sat Feb 2 04:34:56 UTC 2008


On Fri, Feb 01, 2008 at 06:31:11PM -0800, Chris H. wrote:
> I mentioned a problem with this once before, and was referred to
> other threads that also talked about this. But I believe a recent
> problem I was experiencing, may have been related to this:
> [: -le: argument expected. So I'd like to bring it up again, in
> hopes that someone might have a cure. Specifically, two printf()'s
> are sent to the same line, which results in a /very/ hard line to
> decipher.

The two problems you're discussing are entirely 100% unrelated to one
another.  Please do not try and relate them, it will just confuse
readers of both threads.

The problem with [/test on your system is something that's specific to
your system.  I'm hoping the reinstall you're doing (see private mail)
will alleviate this, and if it doesn't, something you're doing after the
fresh install is causing it.  That should be discussed in the other
thread and not here.

The problem with kernel printf()s being interwoven is documented in my
"common issues" file, with numerous threads referenced -- see "Scrambled
dmesg/kernel output" here:

http://jdc.parodius.com/freebsd/common_issues.txt

There is no fix or workaround for this problem.  Someone mentioned
increasing PRINTF_BUFR_SIZE to 128, which does not fix the problem,
nor diminish it in any way.

It's very important that people understand the interwoven kernel output
is specific to stuff printed to the console at the kernel level (e.g. a
driver/module, a piece of the kernel, etc.), and will not happen when
doing something that's output via printf(3) from libc (e.g. output from
"make buildworld", "yes", "ls -FRal /", and so on).

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |



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