On Mon, Feb 10, 2020 at 07:53:20AM -0000, Andrea Righi wrote: > OK, so we know that it's not related to the memory cgroup subsystem.
But this is a good instinct. It does seem to happen when eg firefox or git is in heavy memory use, not the system as a whole. > Another reason of such unexpected swapping activity could be due to > memory compaction code that is triggering some direct memory reclaim and > forcing to swap out pages. > > What do you have in /proc/sys/vm/swappiness? Could you try to set that > to 0 (kernel prefers to drop file-backed pages instead of swapping out > anonymous pages) and see if the swap out activity is still happening? $ cat /proc/sys/vm/swappiness 60 I'll try 0. > Moreover, we can do some more advanced tracing of the direct memory reclaim > code, for example: > $ sudo kprobe-perf -s 'p:shrink_node' > This doesn't work: # kprobe-perf -s 'p:shrink_node' ERROR: func shrink_node not in /sys/kernel/debug/tracing/available_filter_functions. Either it doesn't exist, or, it might be unsafe to kprobe. Exiting. Use -F to override. # ls -l /sys/kernel/debug/tracing/available_filter_functions ls: cannot access '/sys/kernel/debug/tracing/available_filter_functions': No such file or directory # find /sys/kernel/debug/tracing /sys/kernel/debug/tracing /sys/kernel/debug/tracing/instances /sys/kernel/debug/tracing/trace_stat /sys/kernel/debug/tracing/per_cpu /sys/kernel/debug/tracing/per_cpu/cpu7 /sys/kernel/debug/tracing/per_cpu/cpu6 /sys/kernel/debug/tracing/per_cpu/cpu5 /sys/kernel/debug/tracing/per_cpu/cpu4 /sys/kernel/debug/tracing/per_cpu/cpu3 /sys/kernel/debug/tracing/per_cpu/cpu2 /sys/kernel/debug/tracing/per_cpu/cpu1 /sys/kernel/debug/tracing/per_cpu/cpu0 /sys/kernel/debug/tracing/options # Thanks -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1861359 Title: swap storms kills interactive use To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1861359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs