On Tue 06-11-18 21:01:29, Arun KS wrote: > On 2018-11-06 19:36, Michal Hocko wrote: > > On Tue 06-11-18 11:33:13, Arun KS wrote: > > > When free pages are done with higher order, time spend on > > > coalescing pages by buddy allocator can be reduced. With > > > section size of 256MB, hot add latency of a single section > > > shows improvement from 50-60 ms to less than 1 ms, hence > > > improving the hot add latency by 60%. Modify external > > > providers of online callback to align with the change. > > > > > > This patch modifies totalram_pages, zone->managed_pages and > > > totalhigh_pages outside managed_page_count_lock. A follow up > > > series will be send to convert these variable to atomic to > > > avoid readers potentially seeing a store tear. > > > > Is there any reason to rush this through rather than wait for counters > > conversion first? > > Sure Michal. > > Conversion patch, https://patchwork.kernel.org/cover/10657217/ is currently > incremental to this patch. The ordering should be other way around. Because as things stand with this patch first it is possible to introduce a subtle race prone updates. As I've said I am skeptical the race would matter, really, but there is no real reason to risk for that. Especially when you have the other (first) half ready. -- Michal Hocko SUSE Labs
