interacts with interrupts, query ACPI and use MWAIT for entrance into
Cx sleep states. Support C1 "I/O then halt" mode. See Intel'
document 302223-007 "Intelб╝ Processor Vendor-Specific ACPI Interface
Specification" for description.
Move the acpi_cpu_c1() function into x86/cpu_machdep.c and use
it instead of inlining "sti; hlt" sequence in several places.
In the acpi(4) man page, besides documenting the dev.cpu.N.cx_methods
sysctl, correct the names for dev.cpu.N.{cx_usage,cx_lowest,cx_supported}
sysctls.
Both jkim and avg have some other patches implementing the mwait
functionality; this work is unrelated. Linux does not rely on the
ACPI to provide correct tables describing Cx modes. Instead, the
driver has pre-defined knowledge of the CPU models, it was supplied by
Intel.
Tested by: pho (previous versions)
Sponsored by: The FreeBSD Foundation
This includes:
o All directories named *ia64*
o All files named *ia64*
o All ia64-specific code guarded by __ia64__
o All ia64-specific makefile logic
o Mention of ia64 in comments and documentation
This excludes:
o Everything under contrib/
o Everything under crypto/
o sys/xen/interface
o sys/sys/elf_common.h
Discussed at: BSDcan
Use MADT to match ACPI Processor objects to CPUs. MADT and DSDT/SSDTs may
list CPUs in different orders, especially for disabled logical cores. Now
we match ACPI IDs from the MADT with Processor objects, strictly order CPUs
accordingly, and ignore disabled cores. This prevents us from executing
methods for other CPUs, e. g., _PSS for disabled logical core, which may not
exist. Unfortunately, it is known that there are a few systems with buggy
BIOSes that do not have unique ACPI IDs for MADT and Processor objects. To
work around these problems, 'debug.acpi.cpu_unordered' tunable is added.
Set this to a non-zero value to restore the old behavior.
Many thanks to jhb for pointing me to the right direction and the manual
page change.
Reported by: Harris, James R (james dot r dot harris at intel dot com)
Tested by: Harris, James R (james dot r dot harris at intel dot com)
Reviewed by: jhb
MFC after: 1 month
list CPUs in different orders, especially for disabled logical cores. Now
we match ACPI IDs from the MADT with Processor objects, strictly order CPUs
accordingly, and ignore disabled cores. This prevents us from executing
methods for other CPUs, e. g., _PSS for disabled logical core, which may not
exist. Unfortunately, it is known that there are a few systems with buggy
BIOSes that do not have unique ACPI IDs for MADT and Processor objects. To
work around these problems
- "Ns No" is redundant, so reduce it to just "Ns";
- use Li to mark up CPU and system power states because here they are
just strings to be typed literally (add more such mark-up as well);
- the best practice of typesetting tells us to use an en-dash to
indicate a closed range; fortunately, groff_char(7) provides such a symbol.
In addition, consistently use a comma between independent clauses
coordinated by a conjunction.
Pointed out by: ru (mark-up part)
MFC after: 3 days
after. Unify the paths for all Cx states. Remove cpu_idle_busy and
instead do the little profiling we need before re-enabling interrupts.
Use 1 quantum as estimate for C1 sleep duration since the timer interrupt
is the main reason we wake.
While here, change the cx_history sysctl to cx_usage and report statistics
for which idle states were used in terms of percent. This seems more
intuitive than counters. Remove the cx_stats structure since it's no
longer used. Update the man page.
Change various types which do not need explicit size.
Sort acpi debug values. Change "disable" to "disabled" to match rest of
the kernel. Remove debugging from acpi_toshiba since it was only used for
probe/attach.
