hard to merge by lines... (as here we have material differences between
32-bit and 64-bit mode) - will try to do it later.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move the 32-bit and 64-bit gdt_page definitions next to each
other, separated with an #ifdef.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the files more similar in preparation to unification, no
code changed.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
64-bit has X86_HT set too, so use that instead of SMP.
This also removes a include/asm-x86/processor.h ifdef.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Introduce a fast TSC-calibration method on sane hardware.
It only uses 17920 PIT timer ticks to calibrate the TSC, plus 256 ticks on
each side to make sure the TSC values were very close to the tick, so the
whole calibration takes 15ms. Yet, despite only takign 15ms,
we can actually give pretty stringent guarantees of accuracy:
- the code requires that we hit each 256-counter block at least 50 times,
so the TSC error is basically at *MOST* just a few PIT cycles off in
any direction. In practice, it's going to be about one microseconds
off (which is how long it takes to read the counter)
- so over 17920 PIT cycles, we can pretty much guarantee that the
calibration error is less than one half of a percent.
My testing bears this out: on my machine, the quick-calibration reports
2934.085kHz, while the slow one reports 2933.415.
Yes, the slower calibration is still more precise. For me, the slow
calibration is stable to within about one hundreth of a percent, so it's
(at a guess) roughly an order-and-a-half of magnitude more precise. The
longer you wait, the more precise you can be.
However, the nice thing about the fast TSC PIT synchronization is that
it's pretty much _guaranteed_ to give that 0.5% precision, and fail
gracefully (and very quickly) if it doesn't get it. And it really is
fairly simple (even if there's a lot of _details_ there, and I didn't get
all of those right ont he first try or even the second ;)
The patch says "110 insertions", but 63 of those new lines are actually
comments.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/tsc.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 110 insertions(+), 1 deletions(-)
1. add c_x86_vendor into cpu_dev
2. change cpu_devs to static
3. check c_x86_vendor before put that cpu_dev into array
4. remove alignment for 64bit
5. order the sequence in cpu_devs according to link sequence...
so could put intel at first, then amd...
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
v2: make 64 bit get c->x86_cache_alignment = c->x86_clfush_size
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1. add extended_cpuid_level for 32bit
2. add generic_identify for 64bit
3. add early_identify_cpu for 32bit
4. early_identify_cpu not be called by identify_cpu
5. remove early in get_cpu_vendor for 32bit
6. add get_cpu_cap
7. add cpu_detect for 64bit
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move early cpu initialization after cpu early get cap so the
early cpu initialization can fix up cpu caps.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Krzysztof Helt found MTRR is not detected on k6-2
root cause:
we moved mtrr_bp_init() early for mtrr trimming,
and in early_detect we only read the CPU capability from cpuid,
so some cpu doesn't have that bit in cpuid.
So we need to add early_init_xxxx to preset those bit before mtrr_bp_init
for those earlier cpus.
this patch is for v2.6.27
Reported-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
try to insert_resource second time, by expanding the resource...
for case: e820 reserved entry is partially overlapped with bar res...
hope it will never happen
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: aestetic
Capitalize function call interrupts consistently.
All other descriptions in /proc/interrupts are capitalized except
for "function call interrupts". Capitalize it too for consistency.
While that's technically a published ABI I think the risk of anyone
relying on that text to stay the same is negligible.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
this one replaces:
| commit a2bd7274b4
| Author: Yinghai Lu <yhlu.kernel@gmail.com>
| Date: Mon Aug 25 00:56:08 2008 -0700
|
| x86: fix HPET regression in 2.6.26 versus 2.6.25, check hpet against BAR, v3
v2: insert e820 reserve resources before pnp_system_init
v3: fix merging problem in tip/x86/core
v4: address Linus's review about comments and condition in _late()
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
so could let BAR res register at first, or even pnp.
v2: insert e820 reserve resources before pnp_system_init
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The last changes made the calibration loop 250ms long which is far
too much. Try to do that more clever.
Experiments have shown that using a 10ms delay for the PIT based calibration
gives us a good enough value. If we have a reference (HPET/PMTIMER) and the
result of the PIT and the reference is close enough, then we can break out of
the calibration loop on a match right away and use the reference value.
Otherwise we just loop 3 times and decide then, which value to take.
One caveat is that for virtualized environments the PIT calibration often does
not work at all and I found out that 10us is a bit too short as well for the
reference to give a sane result. The solution here is to make the last loop
longer when the first two PIT calibrations failed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When calibration against PIT fails, the warning that we print is misleading.
In a virtualized environment the VM may get descheduled while calibration
or, the check in PIT calibration may fail due to other virtualization
overheads.
The warning message explicitly assumes that calibration failed due to SMI's
which may not be the case. Change that to something proper.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Manually adding "io_delay=0xed" fixes system lockups in ioapic
mode on this machine.
System Information
Manufacturer: Hewlett-Packard
Product Name: Presario F700 (KA695EA#ABF)
Base Board Information
Manufacturer: Quanta
Product Name: 30D3
Reference:
https://bugzilla.redhat.com/show_bug.cgi?id=459546
Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The TSC calibration function is still very complicated, but this makes
it at least a little bit less so by moving the PIT part out into a
helper function of its own.
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>
Larry Finger reported at http://lkml.org/lkml/2008/9/1/90:
An ancient laptop of mine started throwing errors from b43legacy when
I started using 2.6.27 on it. This has been bisected to commit bfc0f59
"x86: merge tsc calibration".
The unification of the TSC code adopted mostly the 64bit code, which
prefers PMTIMER/HPET over the PIT calibration.
Larrys system has an AMD K6 CPU. Such systems are known to have
PMTIMER incarnations which run at double speed. This results in a
miscalibration of the TSC by factor 0.5. So the resulting calibrated
CPU/TSC speed is half of the real CPU speed, which means that the TSC
based delay loop will run half the time it should run. That might
explain why the b43legacy driver went berserk.
On the other hand we know about systems, where the PIT based
calibration results in random crap due to heavy SMI/SMM
disturbance. On those systems the PMTIMER/HPET based calibration logic
with SMI detection shows better results.
According to Alok also virtualized systems suffer from the PIT
calibration method.
The solution is to use a more wreckage aware aproach than the current
either/or decision.
1) reimplement the retry loop which was dropped from the 32bit code
during the merge. It repeats the calibration and selects the lowest
frequency value as this is probably the closest estimate to the real
frequency
2) Monitor the delta of the TSC values in the delay loop which waits
for the PIT counter to reach zero. If the maximum value is
significantly different from the minimum, then we have a pretty safe
indicator that the loop was disturbed by an SMI.
3) keep the pmtimer/hpet reference as a backup solution for systems
where the SMI disturbance is a permanent point of failure for PIT
based calibration
4) do the loop iteration for both methods, record the lowest value and
decide after all iterations finished.
5) Set a clear preference to PIT based calibration when the result
makes sense.
The implementation does the reference calibration based on
HPET/PMTIMER around the delay, which is necessary for the PIT anyway,
but keeps separate TSC values to ensure the "independency" of the
resulting calibration values.
Tested on various 32bit/64bit machines including Geode 266Mhz, AMD K6
(affected machine with a double speed pmtimer which I grabbed out of
the dump), Pentium class machines and AMD/Intel 64 bit boxen.
Bisected-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make poll_idle() behave more like the other idle methods.
Currently, poll_idle() returns immediately. The other
idle methods all wait indefinately for some condition
to come true before returning. poll_idle should emulate
these other methods and also wait for a return condition,
in this case, for need_resched() to become 'true'.
Without this delay the idle loop spends all of its time
in the outer loop that calls poll_idle. This outer loop,
these days, does real work, some of it under rcu locks.
That work should only be done when idle is entered and
when idle exits, not continuously while idle is spinning.
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
