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? The patch as is looks good to me - modulo atomic counters of course. I cannot really judge whether existing updaters do really race in practice to take this riskless. The improvement is nice of course but this is a rare operation and 50ms vs 1ms is hardly noticeable. So I would rather wait for the preparatory work to settle. Btw. is there anything blocking that? It seems to be mostly automated. -- Michal Hocko SUSE Labs
