On Wed, Jan 30, 2019 at 11:11 AM Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > On Tue 29-01-19 21:02:26, Dan Williams wrote: > > When freeing a page with an order >= shuffle_page_order randomly select > > the front or back of the list for insertion. > > > > While the mm tries to defragment physical pages into huge pages this can > > tend to make the page allocator more predictable over time. Inject the > > front-back randomness to preserve the initial randomness established by > > shuffle_free_memory() when the kernel was booted. > > > > The overhead of this manipulation is constrained by only being applied > > for MAX_ORDER sized pages by default. > > I have asked in v7 but didn't get any response. Do we really ned per > free_area random pool? Why a global one is not sufficient? Ah, yes, sorry, overlooked that feedback. A global one is sufficient. Will rework.
