[BRLTTY] BRLTTY Implicated In Resource Exhaustion

[Sabahattin Gucukoglu]

On 9 May 2011, at 01:35, Jason White wrote:
Sabahattin Gucukoglu <mail at sabahattin-gucukoglu.com> wrote:
>> It didn't work, which seems to make sense since I'm not always logged in
>> when it happens.  I did notice, though, that it seemed to be triggered by
>> action on the terminals, either console or display.  Also, brltty seems to
>> die instantly if started up via SSH, as opposed to a VT.
> 
> Do you mean that it causes a segmentation fault, or just that it slows down
> the machine to such an extent as to make interaction impossible? If it's a
> segfault, you'll need to rebuild BRLTTY (preferably the latest version from
> svn) with debug symbols enabled and obtain a backtrace from gdb.

If you mean SSH access, it dies instantly, but not sure without further investigation what the cause is.  If you mean the seemingly random occurrence I started this thread about, it would seem to be just very slow, almost like a very sudden burst of utilisation of memory or a stuck real-time process.

> There's a new 2.6.38 kernel in Debian now, too.

Already installed.

> Strace may also help, as you suggested.

Well, it "Helped" in that it seems to have prevented whatever it was.  I set syslog level to 7, started stracing brltty, and collected about 12 hrs worth of data (about 6GB) with nothing happening.  I dropped strace and debug logging, and soonafter it happened again (as I am writing this, in fact).  Bad luck.  The only thing I changed was the use of the -N (no API) switch, but that didn't and shouldn't permanently fix the problem.  So I will be back to stracing again.

> I don't have any other suggestions, but there are experts on the list and you
> may need to take it up with Debian or the kernel community.

Yes indeed.  On that note, does anybody know of a successful, clean port of brltty to non-Linux, non-Windows systems?  Linux is starting to really fail me of late. :-(

Cheers,
Sabahattin