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

2016-03-30 Thread Hekuang
hi 在 2016/3/31 9:39, Zefan Li 写道: On 2016/3/31 9:14, Hekuang wrote: Hi 在 2016/3/30 19:10, Michal Hocko 写道: On Wed 30-03-16 18:51:12, Hekuang wrote: hi 在 2016/3/30 18:38, Mel Gorman 写道: On Wed, Mar 30, 2016 at 10:22:07AM +, He Kuang wrote: This reverts commit 998d39cb236fe464af86a3492a

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

2016-03-30 Thread Zefan Li
On 2016/3/31 9:14, Hekuang wrote: > Hi > > 在 2016/3/30 19:10, Michal Hocko 写道: >> On Wed 30-03-16 18:51:12, Hekuang wrote: >>> hi >>> >>> 在 2016/3/30 18:38, Mel Gorman 写道: On Wed, Mar 30, 2016 at 10:22:07AM +, He Kuang wrote: > This reverts commit 998d39cb236fe464af86a3492a24d2f67ee1e

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

2016-03-30 Thread Hekuang
Hi 在 2016/3/30 19:10, Michal Hocko 写道: On Wed 30-03-16 18:51:12, Hekuang wrote: hi 在 2016/3/30 18:38, Mel Gorman 写道: On Wed, Mar 30, 2016 at 10:22:07AM +, He Kuang wrote: This reverts commit 998d39cb236fe464af86a3492a24d2f67ee1efc2. When local irq is disabled, a percpu variable does not

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

2016-03-30 Thread Michal Hocko
On Wed 30-03-16 18:51:12, Hekuang wrote: > hi > > 在 2016/3/30 18:38, Mel Gorman 写道: > >On Wed, Mar 30, 2016 at 10:22:07AM +, He Kuang wrote: > >>This reverts commit 998d39cb236fe464af86a3492a24d2f67ee1efc2. > >> > >>When local irq is disabled, a percpu variable does not change, so we can > >>r

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

2016-03-30 Thread Hekuang
hi 在 2016/3/30 18:38, Mel Gorman 写道: On Wed, Mar 30, 2016 at 10:22:07AM +, 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

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

2016-03-30 Thread Mel Gorman
On Wed, Mar 30, 2016 at 10:22:07AM +, 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