Messages in this thread | | | Subject | Re: [RFC PATCH v2 0/4] Eliminate zone->lock contention for will-it-scale/page_fault1 and parallel free | From | Daniel Jordan <> | Date | Fri, 30 Mar 2018 10:27:24 -0400 |
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On 03/29/2018 09:42 PM, Aaron Lu wrote: > On Thu, Mar 29, 2018 at 03:19:46PM -0400, Daniel Jordan wrote: >> On 03/20/2018 04:54 AM, Aaron Lu wrote: >>> This series is meant to improve zone->lock scalability for order 0 pages. >>> With will-it-scale/page_fault1 workload, on a 2 sockets Intel Skylake >>> server with 112 CPUs, CPU spend 80% of its time spinning on zone->lock. >>> Perf profile shows the most time consuming part under zone->lock is the >>> cache miss on "struct page", so here I'm trying to avoid those cache >>> misses. >> >> I ran page_fault1 comparing 4.16-rc5 to your recent work, these four patches >> plus the three others from your github branch zone_lock_rfc_v2. Out of >> curiosity I also threw in another 4.16-rc5 with the pcp batch size adjusted >> so high (10922 pages) that we always stay in the pcp lists and out of buddy >> completely. I used your patch[*] in this last kernel. >> >> This was on a 2-socket, 20-core broadwell server. >> >> There were some small regressions a bit outside the noise at low process >> counts (2-5) but I'm not sure they're repeatable. Anyway, it does improve >> the microbenchmark across the board. > > Thanks for the result. > > The limited improvement is expected since lock contention only shifts, > not entirely gone. So what is interesting to see is how it performs with > v4.16-rc5 + my_zone_lock_patchset + your_lru_lock_patchset
Yep, that's 'coming soon.'
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