freebsd-nq/sys/amd64
Maxim Sobolev 23da540855 The FreeBSD by default "disables" hyper-threading cores, by not scheduling
any threads to them. However, it still counts those cores as "active but
permanently idle" when calculating system-wide CPUs statistics. It is
incorrect, since it skews statistics quite a bit and creates real problems
for certain types of applications (monitoring applications for example),
by making them believe that the system does have enough idle CPU resources,
while in fact it does not.

Correct the problem by not calling performance counting routines on "disabled"
cores. The cleaner solution would be to just disable APIC timer interrupts on
those cores completely, but ENOTIME here and it is not clear if the
additional complexity really worth minor performance gain.

Reviewed by:	ssouhlal
Sponsored by:	Sippy Software, Inc.
MFC after:	2 weeks
2006-09-05 17:15:24 +00:00
..
acpica First pass at allowing memory to be mapped using cache modes other than 2006-08-11 19:22:57 +00:00
amd64 The FreeBSD by default "disables" hyper-threading cores, by not scheduling 2006-09-05 17:15:24 +00:00
compile
conf Remove sio(4) and related options from MI files to amd64, i386 2006-07-29 18:38:54 +00:00
ia32 Retire SYF_ARGMASK and remove both SYF_MPSAFE and SYF_ARGMASK. sy_narg is 2006-07-28 20:22:58 +00:00
include First pass at allowing memory to be mapped using cache modes other than 2006-08-11 19:22:57 +00:00
isa Rework how we wire up interrupt sources to CPUs: 2006-02-28 22:24:55 +00:00
linux32 MFi386 parts of rev 1.55 (modulo real MD parts): 2006-08-28 13:09:24 +00:00
pci MFi386: rename pcib_devclass to hostb_devclass (cosmetic here) 2006-03-13 23:58:40 +00:00
Makefile