On 2024/3/5 10:01, Mina Almasry wrote: ... > > Perf - page-pool benchmark: > --------------------------- > > bench_page_pool_simple.ko tests with and without these changes: > https://pastebin.com/raw/ncHDwAbn > > AFAIK the number that really matters in the perf tests is the > 'tasklet_page_pool01_fast_path Per elem'. This one measures at about 8 > cycles without the changes but there is some 1 cycle noise in some > results. > > With the patches this regresses to 9 cycles with the changes but there > is 1 cycle noise occasionally running this test repeatedly. > > Lastly I tried disable the static_branch_unlikely() in > netmem_is_net_iov() check. To my surprise disabling the > static_branch_unlikely() check reduces the fast path back to 8 cycles, > but the 1 cycle noise remains. > The last sentence seems to be suggesting the above 1 ns regresses is caused by the static_branch_unlikely() checking?
