[gpsd-users] C11 support

[Robin Schwab]

Dear list
When I compile gpsd 3.16 using scons I get a warning
Checking for C header file libkern/OSAtomic.h...
No memory barriers - SHM export and time hinting may not be reliable.

But when I run dpkg -l it reads
ii  cpp              4:4.9.2-2  armhf GNU C preprocessor (cpp)
ii  cpp-4.9          4.9.2-10   armhf GNU C preprocessor

As far as I understand memory barriers are part of c11. The compiler is 
new enough to provide C11 but it's not enabled.

Am I missing something? Or can the warning be ignored?

uname -a gives
Linux piaware 4.4.0-1-rpi2 #1 SMP Debian 4.4.6-1+rpi14 (2016-05-05) 
armv7l GNU/Linux

Regards
Robin