[Pkg-bluetooth-maintainers] Bug#565485: bluez-utils: 'rfcomm listen' wastes a lot of CPU

[Adrian Irving-Beer]

Package: bluez-utils
Version: 4.57-1
Severity: normal

I use 'rfcomm listen' in combination with 'gpspipe' to relay GPS data
from my eeePC to my Blackberry.  I noticed, however, that the CPU
overhead from 'rfcomm listen' is quite significant -- over 10% on my
eeePC 901.

Running 'strace' reveals that rfcomm is in a tight loop between
'waitpid' (with WNOHANG) and 'ppoll' (with a 200 nanosecond(!!)
timeout).  This is evidently the source of the extreme CPU usage.

If it's critical that rfcomm know the child has died ASAP, I would
expect it should be watching for the SIGCHLD signal rather than trying
to use waitpid().  If it's not all that critical, it probably doesn't
need to be watching for child death at a rate of five millions checks
per second. :)

-- System Information:
Debian Release: 5.0.3
  APT prefers stable
  APT policy: (990, 'stable'), (500, 'oldstable'), (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.26-2-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages bluez-utils depends on:
ii  bluetooth                     3.36-3     Bluetooth stack utilities

bluez-utils recommends no packages.

bluez-utils suggests no packages.

-- no debconf information
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