On Thu, Dec 21, 2023 at 08:58:42AM +0800, Yin Fengwei wrote: > Yes. MAP_STACK is also mentioned in manpage of mmap. I did test to > filter out of the MAP_STACK mapping based on this patch. The regression > in stress-ng.pthread was gone. I suppose this is kind of safe because > the madvise call is only applied to glibc allocated stack. > > > But what I am not sure was whether it's worthy to do such kind of change > as the regression only is seen obviously in micro-benchmark. No evidence > showed the other regressionsin this report is related with madvise. At > least from the perf statstics. Need to check more on stream/ramspeed. FWIW, we had a customer report a significant performance problem when inadvertently using 2MB pages for stacks. They were able to avoid it by using 2044KiB sized stacks ...
