What are the ideal ranges for kern.ipc.shm*?

[Ronald Klop]

On Fri, 12 Jul 2013 05:24:55 +0200, Chris H <bsd-lists at 1command.com> wrote:

> Greetings,
>  Over the years using the xfce4 desktop, I would occasionally receive
> SHM ERROR messages. As they never interfered (so's I could notice), I
> always put off attempting to track the cause down. However, now having
> performed a fairly major upgrade (~1yr since last), The error appears
> to greatly affect KDE4 (used to use kde3) applications I run within
> xfce4. The windows don't re-draw correctly, and I receive additional
> errors,as well:
> ...
> Resource id:  0x0
> X Error: BadDrawable (invalid Pixmap or Window parameter) 9
>   Major opcode: 62 (X_CopyArea)
>   Resource id:  0x0
> X Error: BadDrawable (invalid Pixmap or Window parameter) 9
>   Major opcode: 62 (X_CopyArea)
>   Resource id:  0x0
> X Error: BadDrawable (invalid Pixmap or Window parameter) 9
>   Major opcode: 62 (X_CopyArea)
>   Resource id:  0x0
> X Error: BadDrawable (invalid Pixmap or Window parameter) 9
>   Major opcode: 62 (X_CopyArea)
>   Resource id:  0x0
> QCoreApplication::postEvent: Unexpected null receiver
> ...
> After much searching, it would appear to be related to the
> kern.ipc.shm* values.
> pertinent details follow:
> FreeBSD udns 8.4-STABLE FreeBSD 8.4-STABLE #3: Tue Jul  2 13:41:21 PDT  
> 2013
> root at udns:/usr/obj/usr/src/sys/AMD64  amd64
> with 64Gb ram, and 3 cores, and nvidia-driver-308.88_1.
> # ipcs -M
> shminfo:
>         shmmax:     33554432    (max shared memory segment size)
>         shmmin:            1    (min shared memory segment size)
>         shmmni:          192    (max number of shared memory identifiers)
>         shmseg:          128    (max shared memory segments per process)
>         shmall:         8192    (max amount of shared memory in pages)

My 9.1-STABLE amd64 with 4GB RAM has these default settings:
ipcs -M
shminfo:
         shmmax:    536870912    (max shared memory segment size)
         shmmin:            1    (min shared memory segment size)
         shmmni:         1024    (max number of shared memory identifiers)
         shmseg:         1024    (max shared memory segments per process)
         shmall:       131072    (max amount of shared memory in pages)

Regards,
Ronald.