Re: [PATCH] Revert "mm/page_alloc: protect pcp->batch accesses with ACCESS_ONCE"

From: Mel Gorman
Date: Wed Mar 30 2016 - 06:38:51 EST

On Wed, Mar 30, 2016 at 10:22:07AM +0000, He Kuang wrote:
> This reverts commit 998d39cb236fe464af86a3492a24d2f67ee1efc2.
> When local irq is disabled, a percpu variable does not change, so we can
> remove the access macros and let the compiler optimize the code safely.

batch can be changed from other contexts. Why is this safe?

Mel Gorman