There was OpenVZ specific bug rendering some cpufreq drivers unusable on SMP.
In short, when cpufreq code thinks it confined itself to needed cpu by means
of set_cpus_allowed() to execute rdmsr, some "virtual cpu" feature can migrate
process to anywhere. This triggers bugons and does wrong things in general.
This got fixed by introducing rdmsr_on_cpu and wrmsr_on_cpu executing rdmsr
and wrmsr on given physical cpu by means of smp_call_function_single().
Dave Jones mentioned cpufreq might be not only user of rdmsr_on_cpu() and
wrmsr_on_cpu(), so I'm putting them into arch/{i386,x86_64}/lib/ .
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
Support for Core CPUs was broken in two ways in speedstep-lib: for x86_64,
we missed a MSR definition; for both x86_64 and i386, the FSB calculation
was wrong by four (it's a quad-pumped bus). Also increase the accuracy
of the calculation.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>
Add o the x86-64 tree a bunch of MSRs related to performance
monitoring for the processors based on Intel Core microarchitecture.
It also adds some architectural MSRs for PEBS. A similar patch for i386 will
follow.
changelog:
- add Intel Precise-Event Based sampling (PEBS) related MSR
- add Intel Data Save (DS) Area related MSR
- add Intel Core microarchitecure performance counter MSRs
Signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Enable ondemand governor and acpi-cpufreq to use IA32_APERF and IA32_MPERF MSR
to get active frequency feedback for the last sampling interval. This will
make ondemand take right frequency decisions when hardware coordination of
frequency is going on.
Without APERF/MPERF, ondemand can take wrong decision at times due
to underlying hardware coordination or TM2.
Example:
* CPU 0 and CPU 1 are hardware cooridnated.
* CPU 1 running at highest frequency.
* CPU 0 was running at highest freq. Now ondemand reduces it to
some intermediate frequency based on utilization.
* Due to underlying hardware coordination with other CPU 1, CPU 0 continues to
run at highest frequency (as long as other CPU is at highest).
* When ondemand samples CPU 0 again next time, without actual frequency
feedback from APERF/MPERF, it will think that previous frequency change
was successful and can go to wrong target frequency. This is because it
thinks that utilization it has got this sampling interval is when running at
intermediate frequency, rather than actual highest frequency.
More information about IA32_APERF IA32_MPERF MSR:
Refer to IA-32 Intel® Architecture Software Developer's Manual at
http://developer.intel.com
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
This patch adds macros for reading tsc via the RDTSCP instruction, as well
as writing the auxilliary MSR read by RDTSCP to msr.h
[AK: changed rdtscp definition for old binutils]
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Andi Kleen <ak@suse.de>
Ever since we remove msr.c from x86_64 branch and started grabbing it from
i386, msr device (read functionality) has been broken for us.
This is due to the differences between asm-i386/msr.h and asm-x86_64/msr.h interfaces.
Here is a patch to our side to fix this.
Thankfully, as of current (2.6.15-rc1-git6) tree, arch/i386/kernel/msr.c is the only file that uses rdmsr_safe macro.
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I checked with AMD and they requested to only disable it for family 15.
Also disable it for i386 too. And some style fixes.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The only difference was the inline assembly, so move that into
asm/msr.h and merge with the i386 version.
This adds some missing sysfs support code to x86-64.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
They should be identical in the kernel now, but this
makes it consistent with other code.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Harmless because the kernel didn't use it. Noticed by Travis Betak
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This will allow hotplug CPU in the future and in general cleans up a lot of
crufty code. It also should plug some races that the old hackish way
introduces. Remove one old race workaround in NMI watchdog setup that is not
needed anymore.
I removed the old total sum of bogomips reporting code. The brag value of
BogoMips has been greatly devalued in the last years on the open market.
Real CPU hotplug will need some more work, but the infrastructure for it is
there now.
One drawback: the new TSC sync algorithm is less accurate than before. The
old way of zeroing TSCs is too intrusive to do later. Instead the TSC of the
BP is duplicated now, which is less accurate.
akpm:
- sync_tsc_bp_init seems to have the sense of `init' inverted.
- SPIN_LOCK_UNLOCKED is deprecated - use DEFINE_SPINLOCK.
Cc: <rusty@rustcorp.com.au>
Cc: <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Adrian Bunk