On Mon, Jul 15, 2024 at 7:10 AM Ryan Roberts <ryan.roberts@xxxxxxx> wrote: > > On 11/07/2024 15:08, Chris Li wrote: > > On Thu, Jul 11, 2024 at 3:02 AM Ryan Roberts <ryan.roberts@xxxxxxx> wrote: > >> > >>> Kernel compile under tmpfs with cgroup memory.max = 2G. > >>> 12 core 24 hyperthreading, 32 jobs. > >>> > >>> HDD swap 3 runs average, 20G swap file: > >>> > >>> Without: > >>> user 4186.290 > >>> system 421.743 > >>> real 597.317 > >>> > >>> With: > >>> user 4113.897 > >>> system 413.123 > >>> real 659.543 > >> > >> If I've understood this correctly, this test is taking~10% longer in wall time? > > > > Most likely due to the high variance in measurement and fewer > > measuring samples 3 vs 10. Most of that wall time is waiting for IO. > > It is likely just noise. > > OK, that certainly makes sense, as long as you're sure its noise. The other > (unlikely) possibility is that somehow the HDD placement descisions are > changing, which increases waiting due to increased seek times. I sure did not change the HDD placement, if the HDD allocation is different from the previous code, that should be a bug. I mostly remove the cluster code path in HDD swap entry allocation. I did the HDD run mostly to make sure the HDD can still take some stress test on the swapping without crashing. Chris
