Bharata B Rao <bharata@xxxxxxx> writes: > On 13-Feb-23 12:00 PM, Huang, Ying wrote: >>> I have a microbenchmark where two sets of threads bound to two >>> NUMA nodes access the two different halves of memory which is >>> initially allocated on the 1st node. >>> >>> On a two node Zen4 system, with 64 threads in each set accessing >>> 8G of memory each from the initial allocation of 16G, I see that >>> IBS driven NUMA balancing (i,e., this patchset) takes 50% less time >>> to complete a fixed number of memory accesses. This could well >>> be the best case and real workloads/benchmarks may not get this much >>> uplift, but it does show the potential gain to be had. >> >> Can you find a way to show the overhead of the original implementation >> and your method? Then we can compare between them? Because you think >> the improvement comes from the reduced overhead. > > Sure, will measure the overhead. > >> >> I also have interest in the pages migration throughput per second during >> the test, because I suspect your method can migrate pages faster. > > I have some data on pages migrated over time for the benchmark I mentioned > above. > > > Pages migrated vs Time(s) > 2500000 +---------------------------------------------------------------+ > | + + + + + + + | > | Default ******* | > | IBS ####### | > | | > | ****************************| > | * | > 2000000 |-+ * +-| > | * | > | ** | > P | * ## | > a | *### | > g | **# | > e 1500000 |-+ *## +-| > s | ## | > | # | > m | # | > i | *# | > g | *# | > r | ## | > a 1000000 |-+ # +-| > t | # | > e | #* | > d | #* | > | # * | > | # * | > 500000 |-+ # * +-| > | # * | > | # * | > | # * | > | ## * | > | # * | > | # + * + + + + + + | > 0 +---------------------------------------------------------------+ > 0 20 40 60 80 100 120 140 160 > Time (s) > > So acting upon the relevant accesses early enough seem to result in > pages migrating faster in the beginning. One way to prove this is to output the benchmark performance periodically. So we can find how the benchmark score change over time. Best Regards, Huang, Ying > Here is the actual data in case the above ascii graph gets jumbled up: > > numa_pages_migrated vs time in seconds > ====================================== > > Time Default IBS > --------------------------- > 5 2639 511 > 10 2639 17724 > 15 2699 134632 > 20 2699 253485 > 25 2699 386296 > 30 159805 524651 > 35 450678 667622 > 40 741762 811603 > 45 971848 950691 > 50 1108475 1084537 > 55 1246229 1215265 > 60 1385920 1336521 > 65 1508354 1446950 > 70 1624068 1544890 > 75 1739311 1629162 > 80 1854639 1700068 > 85 1979906 1759025 > 90 2099857 <end> > 95 2099857 > 100 2099857 > 105 2099859 > 110 2099859 > 115 2099859 > 120 2099859 > 125 2099859 > 130 2099859 > 135 2099859 > 140 2099859 > 145 2099859 > 150 2099859 > 155 2099859 > 160 2099859 > > Regards, > Bharata.
