On 2/23/24 12:39, John Groves wrote: >> We had similar unit test regression concerns with fsdax where some >> upstream change silently broke PMD faults. The solution there was trace >> points in the fault handlers and a basic test that knows apriori that it >> *should* be triggering a certain number of huge faults: >> >> https://github.com/pmem/ndctl/blob/main/test/dax.sh#L31 > Good approach, thanks Dan! My working assumption is that we'll be able to make > that approach work in the famfs tests. So the fault counters should go away > in the next version. I do really suspect there's something more generic that should be done here. Maybe we need a generic 'huge_faults' perf event to pair up with the good ol' faults that we already have: # perf stat -e faults /bin/ls Performance counter stats for '/bin/ls': 104 faults 0.001499862 seconds time elapsed 0.001490000 seconds user 0.000000000 seconds sys
