[CentOS] Starting emacs gives "shmget failed: error 28" message

[Nicolas Thierry-Mieg]

On 09/03/2015 03:04 AM, Robert Nichols wrote:
> In CentOS 6.7, if I start emacs from a terminal session, I always see
> a message, "(emacs:{PID}): Gdk-WARNING **: shmget failed: error 28 (No
> space left on device)"
>
> The message is also logged to .xsession-errors, and that occurs
> regardless of how emacs is started. The same thing occurs with
> SELinux in permissive mode.
>
> Emacs version is emacs-23.1-28.el6.x86_64 .
>
> Output from strace shows:
>     shmget(IPC_PRIVATE, 393216, IPC_CREAT|0600) = -1 ENOSPC (No space
> left on device)
>
> /proc/mounts contains:
>     tmpfs /dev/shm tmpfs rw,seclabel,relatime 0 0
>
> and "df /dev/shm" shows:
>     Filesystem     1K-blocks  Used Available Use% Mounted on
>     tmpfs            8194164   172   8193992   1% /dev/shm
>
> I can't identify any behavior problems that I can relate to this,
> but it seems that something is wrong.  Any clues as to what?
>

just a shot in the dark, but what do you have in
/proc/sys/kernel/shmmni ?

According to man shmget:
ENOSPC All possible shared memory IDs have been taken  (SHMMNI),  or 
allocating  a  segment  of  the requested  size  would  cause  the 
system  to  exceed  the system-wide limit on shared memory (SHMALL).