cupsd takes 99% CPU when BrowsePoll is used, cups-polld not taken down when CUPS is stopped

This bug is still present in 6.06 beta as of 20060524

Plus, in dapper, cupsd goes to 99% after a normal boot. And I can't print!

Ok, came across a solution:

$ sudo apt-get --purge remove cupsys cups-pdf
$ cd /var/cache
$ sudo rm -rf cupsd/
$ cd /var/run
$ sudo rm -rf cupsd/

Something was stiking around from Breezy which prevents cupsd from running properly.

I have the same problem as the initial poster in Edgy. If I add a BrowsePoll line in my cupsd.conf, cupsd starts eating all the CPU it can get. If I remove the line and restart, it goes back to normal.

The server pointed to by the BrowsePoll line works fine, which I verified by running "CUPS_SERVER=<thehost> lpstat -a".

Also, when I stop cups, I get a "cups-polld" run by root that doesn't go away. Why does that process have to run as root.

stracing shows that cupsd is doing a lot of select(). The cups-polld seems to be actually talking to the other server.

This is the output of "dpkg -l cups\*"

un cups <none> (no description available)
un cups-pdf <none> (no description available)
un cupsomatic-ppd <none> (no description available)
ii cupsys 1.2.4-2ubuntu3 Common UNIX Printing System(tm) - server
ii cupsys-bsd 1.2.4-2ubuntu3 Common UNIX Printing System(tm) - BSD comman
ii cupsys-client 1.2.4-2ubuntu3 Common UNIX Printing System(tm) - client pro
ii cupsys-common 1.2.4-2ubuntu3 Common UNIX Printing System(tm) - common fil
ii cupsys-driver- 5.0.0-2ubuntu2 printer drivers for CUPS
pn cupsys-driver- <none> (no description available)
ii cupsys-driver- 5.0.0-2ubuntu2 printer drivers for CUPS
un cupsys-pstoras <none> (no description available)
un cupsys-pt <none> (no description available)

In Feisty (CUPS 1.2.7) the 100% CPU problem disappears, probably due to the following fix:

http://www.cups.org/str.php?L1994

The problem of cups-polld running as root and therefore not taken down when cupsys is stopped still persists. I recommend to expand the cupsys run-as-user patch to also let the sub-daemons (cups-polld and cups-lpd) drop their privileges as soon as possible. This way CUPS can kill these daemons and as a side effect the security of these daemons is improved.

 cupsys (1.2.7-4ubuntu2) feisty; urgency=low
 .
   * debian/local/enable_sharing: Fix regex to find both 127.0.0.1 and
     'localhost' to fix enabling sharing the second time. Closes: LP#75903
   * debian/patches/09_runasuser.dpatch: Drop root privileges of cups-polld
     after creating the socket. This allows cupsd to kill polld on shutdown,
     and has the nice side effect of improving security. Closes: LP#30965

Still have to do the same for cups-lpd, so not closing yet.

This should not be an issue any more in Gutsy, since the root dropping patches have been removed.