On Tue, Nov 9, 2021 at 3:29 PM Jan Stary <h...@stare.cz> wrote: > On Nov 10 00:21:59, h...@stare.cz wrote: > > Regarding C states, this machine has > > > > acpicpu0 at acpi0: C3(350@96 mwait.1@0x20), C2(500@64 mwait.1@0x10), > C1(1000@1 mwait.1), PSS > > > > I suppose the cpu supports C1, C2, C3, but can someone please kindly > > explain (or point to an explanation of) what the whole line says? > > For comparison, my Thinkpad T400 has > acpicpu0 at acpi0: !C3(100@57 mwait.3@0x30), !C2(500@1 mwait.1@0x10), > C1(1000@1 mwait.1), PSS > What does the ! mean? >
This is generated by sys/dev/acpi/acpicpu.c:acpicpu_print_one_cst() and at this point should either be suppressed by default or documented in the manpage; I'm not sure which. To enumerate it from right to left: !C3(100@57 mwait.3@0x30) ^ ^ ^ ^ ^ ^ ^ | | | | | | | | | | | | | \-- 'hints' passed to the actual MWAIT instruction, or address for 'io' method | | | | | \-- fixed-function level bit flags: 1="HW coordinated" 2="bus-master avoidance required" | | | | | OR '!' if this is a faked-up fallback to the pre-CST C1-via-HALT (bios is broken) | | | | \-- sleep method, one of mwait, io, or halt | | | \-- advertised latency when exiting the state | | \-- advertised power-consumption | \-- the C state, duh \-- '!' to indicate this state is disabled because the CPU's LAPIC stops in C2 or deeper (no ARAT)
