On Sat, Feb 19, 2022 at 12:14:16PM -0500, Alexander Motin wrote: > On 19.02.2022 12:02, Mike Karels wrote: > > On 18 Feb 2022, at 20:55, Tomoaki AOKI wrote: > > > Just a thought, but can it be the reason with timing (e.g., rendezvous > > > within (i)threads, hardware controlls without using hardware timer) > > > problem? > > > > > > On FreeBSD, IIUC, multi processor (multi core) implementation assumes > > > SMP (differs only clock speed) and end up with difference of > > > performance at same clock speed within P-core and E-core, possibly. > > > > Another possibility is that the system is confused by having hyperthreading > > on the P cores but not the E cores. > > No, I've tried to disable SMT and different number of cores to make it look > identical and uniform for the scheduler. The only thing I could not test is > disabling all P cores to test only E, the motherboard does not allow that, > requiring at least one P core enabled.
Does the kernel select MWAIT as the idle method? If you set idle to spin, is anything change?
