freebsd-dev/sys/amd64/include
Conrad Meyer 665919aaaf x86: Implement MWAIT support for stopping a CPU
IPI_STOP is used after panic or when ddb is entered manually.  MONITOR/
MWAIT allows CPUs that support the feature to sleep in a low power way
instead of spinning.  Something similar is already used at idle.

It is perhaps especially useful in oversubscribed VM environments, and is
safe to use even if the panic/ddb thread is not the BSP.  (Except in the
presence of MWAIT errata, which are detected automatically on platforms with
known wakeup problems.)

It can be tuned/sysctled with "machdep.stop_mwait," which defaults to 0
(off).  This commit also introduces the tunable
"machdep.mwait_cpustop_broken," which defaults to 0, unless the CPU has
known errata, but may be set to "1" in loader.conf to signal that mwait
wakeup is broken on CPUs FreeBSD does not yet know about.

Unfortunately, Bhyve doesn't yet support MONITOR extensions, so this doesn't
help bhyve hypervisors running FreeBSD guests.

Submitted by:   Anton Rang <rang AT acm.org> (earlier version)
Reviewed by:	kib
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D20135
2019-05-04 20:34:26 +00:00
..
pc sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
xen x86/xen: Consolidate xen-os.h in a single place 2015-10-21 10:04:35 +00:00
_align.h
_bus.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
_inttypes.h
_limits.h
_stdint.h
_types.h
acpica_machdep.h
apm_bios.h
asm.h Remove lint support from system headers and MD x86 headers. 2017-11-23 11:40:16 +00:00
asmacros.h Use SMAP on amd64. 2018-07-29 20:47:00 +00:00
atomic.h Make sure kernel modules built by default are portable between UP and 2018-07-06 10:13:42 +00:00
bus_dma.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
bus.h
clock.h re-synchronize TSC-s on SMP systems after resume, if necessary 2018-05-25 07:33:20 +00:00
counter.h Expand x86 struct pcpus to UMA_PCPU_ALLOC_SIZE AKA PAGE_SIZE. 2018-07-06 19:50:44 +00:00
cpu.h Add a custom implementation of cpu_lock_delay() for x86. 2018-11-05 22:54:03 +00:00
cpufunc.h Provide convenience C wrappers for RDPKRU and WRPKRU instructions. 2019-02-19 19:17:20 +00:00
cputypes.h Remove 'cpu' and 'cpu_class' on amd64. 2016-09-15 17:05:54 +00:00
db_machdep.h Cleanups related to debug exceptions on x86. 2018-05-22 00:45:00 +00:00
dump.h
efi.h Catch exceptions during EFI RT calls on amd64. 2018-09-02 21:37:05 +00:00
elf.h
endian.h
exec.h sys: further adoption of SPDX licensing ID tags. 2017-11-20 19:43:44 +00:00
fdt.h
float.h
floatingpoint.h spdx: initial adoption of licensing ID tags. 2017-11-18 14:26:50 +00:00
fpu.h Remove unused error return from API that cannot fail 2018-02-23 20:15:19 +00:00
frame.h PTI for amd64. 2018-01-17 11:44:21 +00:00
gdb_machdep.h amd64: Protect the kernel text, data, and BSS by setting the RW/NX bits 2018-03-06 14:28:37 +00:00
ieeefp.h Resolve conflicts between macros in fenv.h and ieeefp.h 2018-05-31 20:22:47 +00:00
in_cksum.h sys: further adoption of SPDX licensing ID tags. 2017-11-20 19:43:44 +00:00
intr_machdep.h Drop "All rights reserved" from my copyright statements. 2019-03-06 22:11:45 +00:00
iodev.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
kdb.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
limits.h sys: further adoption of SPDX licensing ID tags. 2017-11-20 19:43:44 +00:00
md_var.h Add pci_early function to detect Intel stolen memory. 2018-10-31 23:17:00 +00:00
memdev.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
metadata.h Move amd64 metadata.h to x86 and share with i386 2016-01-07 19:47:26 +00:00
minidump.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
mp_watchdog.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
nexusvar.h
npx.h
ofw_machdep.h
param.h spdx: initial adoption of licensing ID tags. 2017-11-18 14:26:50 +00:00
pcb.h PTI: Trap if we returned to userspace with kernel (full) page table 2018-01-19 22:10:29 +00:00
pci_cfgreg.h
pcpu.h x86: Implement MWAIT support for stopping a CPU 2019-05-04 20:34:26 +00:00
pmap.h Add kernel support for Intel userspace protection keys feature on 2019-02-20 09:51:13 +00:00
pmc_mdep.h hwpmc: ABI fixes 2018-06-04 02:05:48 +00:00
ppireg.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
proc.h amd64: Add md process flags and first P_MD_PTI flag. 2019-03-16 11:31:01 +00:00
procctl.h amd64 KPTI: add control from procctl(2). 2019-03-16 11:44:33 +00:00
profile.h Fix high resolution kernel profiling just enough to not crash at boot 2018-06-02 05:48:44 +00:00
psl.h
ptrace.h
pvclock.h
reg.h
reloc.h sys: further adoption of SPDX licensing ID tags. 2017-11-20 19:43:44 +00:00
resource.h
runq.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
segments.h sys: further adoption of SPDX licensing ID tags. 2017-11-20 19:43:44 +00:00
setjmp.h
sf_buf.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
sgx.h Add support for Intel Software Guard Extensions (Intel SGX). 2017-08-16 10:38:06 +00:00
sgxreg.h Add support for Intel Software Guard Extensions (Intel SGX). 2017-08-16 10:38:06 +00:00
sigframe.h
signal.h
smp.h x86: improve reservation of AP trampoline memory 2018-04-05 14:39:51 +00:00
specialreg.h
stack.h
stdarg.h
sysarch.h
timerreg.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
trap.h
tss.h sys: further adoption of SPDX licensing ID tags. 2017-11-20 19:43:44 +00:00
ucontext.h
vdso.h
vm.h sys/amd64: further adoption of SPDX licensing ID tags. 2017-11-27 15:03:07 +00:00
vmm_dev.h Add the ability to control the CPU topology of created VMs 2018-04-08 19:24:49 +00:00
vmm_instruction_emul.h Add a new variant of the GLA2GPA ioctl for use by the debug server. 2018-02-26 19:19:05 +00:00
vmm.h Add accessor function for vm->maxcpus 2019-04-25 22:51:36 +00:00
vmparam.h Provide pmap_large_map() KPI on amd64. 2018-10-16 17:28:10 +00:00