diff options
| author |   Andi Kleen <ak@suse.de> | 2006-02-03 21:50:50 +0100 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-04 16:43:13 -0800 |
| commit | 73dea47faeb96d54a984b9d7f4de564816966354 (patch) | |
| tree | 6b1f090e9071e281367bc106c1b2ab05cb43e459 /Documentation | |
| parent | [PATCH] x86_64: Only switch to IPI broadcast timer on Intel when C3 is supported (diff) | |
| download | linux-dev-73dea47faeb96d54a984b9d7f4de564816966354.tar.xz linux-dev-73dea47faeb96d54a984b9d7f4de564816966354.zip | |
[PATCH] x86_64: Allow to run main time keeping from the local APIC interrupt
Another piece from the no-idle-tick patch.
This can be enabled with the "apicmaintimer" option.
This is mainly useful when the PIT/HPET interrupt is unreliable.
Note there are some systems that are known to stop the APIC
timer in C3. For those it will never work, but this case
should be automatically detected.
It also only works with PM timer right now. When HPET is used
the way the main timer handler computes the delay doesn't work.
It should be a bit more efficient because there is one less
regular interrupt to process on the boot processor.
Requires earlier bugfix from Venkatesh
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/x86_64/boot-options.txt | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 9c5fc15d03d1..654ea4fccff8 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -40,6 +40,13 @@ APICs no_timer_check Don't check the IO-APIC timer. This can work around problems with incorrect timer initialization on some boards. + apicmaintimer Run time keeping from the local APIC timer instead + of using the PIT/HPET interrupt for this. This is useful + when the PIT/HPET interrupts are unreliable. + + noapicmaintimer Don't do time keeping using the APIC timer. + Useful when this option was auto selected, but doesn't work. + Early Console syntax: earlyprintk=vga |