Re: Qeustion about memory barrier in sys_getppid() system call .

["Bhanu Kalyan Chetlapalli" <chbhanukalyan@xxxxxxxxx>]

On 7/19/07, Henrik Austad <henrik.austad@xxxxxxxxx > wrote:

Please correct me if I have this all wrong but,

> First, be aware that the barrier is done only when SMP support *or* full
> kernel level preemption is enabled.

isn't the barrier also for the compiler? IIRC, gcc reorder instructions in an
attempt to optimize code. A memory-barrier will effectively stop the compiler
for mixing code from before the barrier into the code afterwards.

Yes, Even compilers can play around with the value trying to optimize code. So AFAIK barriers work as hints to the compilers too...

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