https://bugzilla.suse.com/show_bug.cgi?id=1209102 Bug ID: 1209102 Summary: Regressions in gitsource between 6.1 and 6.2 Classification: openSUSE Product: openSUSE Tumbleweed Version: Current Hardware: Other OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: Kernel Assignee: kernel-bugs@opensuse.org Reporter: jack@suse.com QA Contact: qa-bugs@suse.de Found By: --- Blocker: --- Our performance testing infrastructure has noticed that gitsource benchmark has regressed between 6.1 and 6.2 upstream kernel versions on some machines. It has bisected the regression to commit f1a7941243c1 ("mm: convert mm's rss stats into percpu_counter"). The regression was detected on many machines in our performance testing grid. On pumbaa the difference is very visible: before (9cd6ffa6025) after (f1a7941243c1) Amean User 471.12 * 0.30%* 481.77 * -1.96%* Amean System 244.47 * 0.90%* 269.13 * -9.09%* Amean Elapsed 709.22 * 0.45%* 742.27 * -4.19%* Amean CPU 100.00 ( 0.20%) 101.00 * -0.80%* We can see the biggest difference in the "System time" and still noticeable difference in the "Elapsed time". The benchmark runs 'make test' in a checked-out sources of git (fixed to a particular version) so it is effectively heavily exercising shell scripting and spawning lots of shortlived tasks. So I suspect the setup cost of the percpu counters may be playing role here. -- You are receiving this mail because: You are the assignee for the bug.