Re: [PATCH 4/9] net: openvswitch: use this_cpu_ptr per-cpu helper

On Thu, Nov 1, 2012 at 7:33 AM, Christoph Lameter [off-list ref] wrote:

On Thu, 1 Nov 2012, Shan Wei wrote:

quoted

But for different field in same per-cpu variable, how to guarantee n_missed
and n_hit are from same cpu?
this_cpu_read(dp->stats_percpu->n_missed);
[processor changed]
this_cpu_read(dp->stats_percpu->n_hit);

What does current guarantee that? If it is guaranteed then you can use the
__this_cpu_xxx ops.

Preemption is disabled in all of the places where writes are done and
all of the reads are from foreign CPUs.