On 10/2/20, 6:05 PM, "Andrew Morton" <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: On Fri, 2 Oct 2020 01:06:21 -0700 John Hubbard <jhubbard@xxxxxxxxxx> wrote: > This patch reduces the running time for compaction_test from about 27 > sec, to 3.3 sec, which is about an 8x speedup. > > These numbers are for an Intel x86_64 system with 32 GB of DRAM. > > The compaction_test.c program was spending most of its time doing > mmap(), 1 MB at a time, on about 25 GB of memory. > > Instead, do the mmaps 100 MB at a time. (Going past 100 MB doesn't make > things go much faster, because other parts of the program are using the > remaining time.) Seems nice. It's been 5 years, but hopefully Sri is still at Akamai? Looks good to me. Thanks -Sri