Performance issues in cups 1.3

[angelb]

> > Does anyone know if this performance issue been addressed in 1.3.6?
>
> We haven't added any additional tests WRT poll() since the issue
> was limited to specific versions of HP-UX not honoring the poll()
> timeout.
>
> > I'm testing 1.3.5 and running into the same problem with AIX and
> > Solaris clients.
>
> It would be useful to find out where the performance bottleneck is.
> Have you done any profiling to determine where cupsd is spending the
> most time?

Ok, I had a chance to run some statistics on one AIX 5.2 system.

Running lpstat -p: (AIX 5.2)

Here, cupsd is using 11.94% CPU which is spent most of its time in the
kernel and shared libraries.

Process                                Freq  Total Kernel   User Shared  Other
=======                                ====  ===== ======   ==== ======  =====
wait                                      2  73.95  73.95   0.00   0.00   0.00
cupsd                                     1  11.94   6.32   0.88   4.74   0.00
/usr/openv/netbackup/bin/bptm             1   4.63   4.55   0.00   0.08   0.00
/opt/TWWfsw/bin/lpstat                    1   3.55   1.00   0.36   2.20   0.00


Breakdown of CPU usage by PID:

Process                   PID      TID  Total Kernel   User Shared  Other
=======                   ===      ===  ===== ======   ==== ======  =====
wait                    12294    12295  38.00  38.00   0.00   0.00   0.00
wait                     8196     8197  35.95  35.95   0.00   0.00   0.00
cupsd                  430266   999529  11.94   6.32   0.88   4.74   0.00
v/netbackup/bin/bptm   626814   553213   4.63   4.55   0.00   0.08   0.00


Shared Object                                                             %
=============                                                          ======
/usr/lib/libc.a[shr.o]                                                   5.26
/opt/TWWfsw/cups135/lib/libcups.so                                       2.08


Probably irrelevant(shown for completeness):
Subroutine                                            %   Source
==========                                         ====== ======
.waitproc_find_run_queue                            44.51 rnel/proc/dispatch.c
.waitproc                                           20.04 rnel/proc/dispatch.c


Subroutine                                            %   Source
==========                                         ====== ======
._doprnt                                             1.01 cs/lib/libc/doprnt.c


I'm reinstalling CUPS on the other AIX system. Whenever I do an
lpstat, cupsd dies(disappear) and no error is produced. Hopefully,
with the reinstall, it clear things up a bit. I will also try to get
statistics on the Solaris system.

Thanks,
Angel