Re: [v3,11/41] mips: reuse asm-generic/barrier.h
From: Peter Zijlstra <peterz@infradead.org>
Date: 2016-01-15 08:56:17
Also in:
linux-arch, linux-arm-kernel, linux-mips, linux-s390, linux-sh, linuxppc-dev, lkml, sparclinux
On Thu, Jan 14, 2016 at 01:29:13PM -0800, Paul E. McKenney wrote:
So smp_mb() provides transitivity, as do pairs of smp_store_release() and smp_read_acquire(),
But they provide different grades of transitivity, which is where all the confusion lays. smp_mb() is strongly/globally transitive, all CPUs will agree on the order. Whereas the RCpc release+acquire is weakly so, only the two cpus involved in the handover will agree on the order.