Presently acpi-cpufreq will perform the MSR read on the first CPU in the
mask. That's inefficient if that CPU differs from the current CPU.
Because we have to perform a cross-CPU call, but we could have run the
rdmsr on the current CPU.
So switch to using the new smp_call_function_any(), which will perform the
call on the current CPU if that CPU is present in the mask (it is).
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
m68k: rename global variable vmalloc_end to m68k_vmalloc_end
percpu: add missing per_cpu_ptr_to_phys() definition for UP
percpu: Fix kdump failure if booted with percpu_alloc=page
percpu: make misc percpu symbols unique
percpu: make percpu symbols in ia64 unique
percpu: make percpu symbols in powerpc unique
percpu: make percpu symbols in x86 unique
percpu: make percpu symbols in xen unique
percpu: make percpu symbols in cpufreq unique
percpu: make percpu symbols in oprofile unique
percpu: make percpu symbols in tracer unique
percpu: make percpu symbols under kernel/ and mm/ unique
percpu: remove some sparse warnings
percpu: make alloc_percpu() handle array types
vmalloc: fix use of non-existent percpu variable in put_cpu_var()
this_cpu: Use this_cpu_xx in trace_functions_graph.c
this_cpu: Use this_cpu_xx for ftrace
this_cpu: Use this_cpu_xx in nmi handling
this_cpu: Use this_cpu operations in RCU
this_cpu: Use this_cpu ops for VM statistics
...
Fix up trivial (famous last words) global per-cpu naming conflicts in
arch/x86/kvm/svm.c
mm/slab.c
This interface is mainly intended (and implemented) for ACPI _PPC BIOS
frequency limitations, but other cpufreq drivers can also use it for
similar use-cases.
Why is this needed:
Currently it's not obvious why cpufreq got limited.
People see cpufreq/scaling_max_freq reduced, but this could have
happened by:
- any userspace prog writing to scaling_max_freq
- thermal limitations
- hardware (_PPC in ACPI case) limitiations
Therefore export bios_limit (in kHz) to:
- Point the user that it's the BIOS (broken or intended) which limits
frequency
- Export it as a sysfs interface for userspace progs.
While this was a rarely used feature on laptops, there will appear
more and more server implemenations providing "Green IT" features like
allowing the service processor to limit the frequency. People want
to know about HW/BIOS frequency limitations.
All ACPI P-state driven cpufreq drivers are covered with this patch:
- powernow-k8
- powernow-k7
- acpi-cpufreq
Tested with a patched DSDT which limits the first two cores (_PPC returns 1)
via _PPC, exposed by bios_limit:
# echo 2200000 >cpu2/cpufreq/scaling_max_freq
# cat cpu*/cpufreq/scaling_max_freq
2600000
2600000
2200000
2200000
# #scaling_max_freq shows general user/thermal/BIOS limitations
# cat cpu*/cpufreq/bios_limit
2600000
2600000
2800000
2800000
# #bios_limit only shows the HW/BIOS limitation
CC: Pallipadi Venkatesh <venkatesh.pallipadi@intel.com>
CC: Len Brown <lenb@kernel.org>
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.net
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
Removing the SMT/HT check, since the Errata doesn't mention
Hyper-Threading.
Adding in a printk, so that the user knows why acpi-cpufreq refuses to
load. Also, once system is blacklisted, don't repeat checks to see if
blacklisted. This also causes the message to only be printed once,
rather than for each CPU.
Signed-off-by: John L. Villalovos <john.l.villalovos@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
This patch updates percpu related symbols in cpufreq such that percpu
symbols are unique and don't clash with local symbols. This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.
* drivers/cpufreq/cpufreq.c: s/policy_cpu/cpufreq_policy_cpu/
* drivers/cpufreq/freq_table.c: s/show_table/cpufreq_show_table/
* arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: s/drv_data/acfreq_data/
s/old_perf/acfreq_old_perf/
Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
* 'perfcounters-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (58 commits)
perf_counter: Fix perf_copy_attr() pointer arithmetic
perf utils: Use a define for the maximum length of a trace event
perf: Add timechart help text and add timechart to "perf help"
tracing, x86, cpuidle: Move the end point of a C state in the power tracer
perf utils: Be consistent about minimum text size in the svghelper
perf timechart: Add "perf timechart record"
perf: Add the timechart tool
perf: Add a SVG helper library file
tracing, perf: Convert the power tracer into an event tracer
perf: Add a sample_event type to the event_union
perf: Allow perf utilities to have "callback" options without arguments
perf: Store trace event name/id pairs in perf.data
perf: Add a timestamp to fork events
sched_clock: Make it NMI safe
perf_counter: Fix up swcounter throttling
x86, perf_counter, bts: Optimize BTS overflow handling
perf sched: Add --input=file option to builtin-sched.c
perf trace: Sample timestamp and cpu when using record flag
perf tools: Increase MAX_EVENT_LENGTH
perf tools: Fix memory leak in read_ftrace_printk()
...
This patch converts the existing power tracer into an event tracer,
so that power events (C states and frequency changes) can be
tracked via "perf".
This also removes the perl script that was used to demo the tracer;
its functionality is being replaced entirely with timechart.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090912130542.6d314860@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ] Fix NULL ptr regression in powernow-k8
[CPUFREQ] Create a blacklist for processors that should not load the acpi-cpufreq module.
[CPUFREQ] Powernow-k8: Enable more than 2 low P-states
[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)
[CPUFREQ] ondemand - Use global sysfs dir for tuning settings
[CPUFREQ] Introduce global, not per core: /sys/devices/system/cpu/cpufreq
[CPUFREQ] Bail out of cpufreq_add_dev if the link for a managed CPU got created
[CPUFREQ] Factor out policy setting from cpufreq_add_dev
[CPUFREQ] Factor out interface creation from cpufreq_add_dev
[CPUFREQ] Factor out symlink creation from cpufreq_add_dev
[CPUFREQ] cleanup up -ENOMEM handling in cpufreq_add_dev
[CPUFREQ] Reduce scope of cpu_sys_dev in cpufreq_add_dev
[CPUFREQ] update Doc for cpuinfo_cur_freq and scaling_cur_freq
Move some of the aperf/mperf code out from the cpufreq driver
thingy so that other people can enjoy it too.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: cpufreq@vger.kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move the APERFMPERF capacility into a X86_FEATURE flag so that it
can be used outside of the acpi cpufreq driver.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: cpufreq@vger.kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Create a blacklist for processors that should not load the acpi-cpufreq module.
The initial entry in the blacklist function is the Intel 0f68 processor. It's
specification update mentions errata AL30 which implies that cpufreq should not
run on this processor.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The VIA/Centaur C7, C7-M and Nano CPU's all support ACPI based cpu p-states
using a MSR interface. The Linux driver just never made use of it, since in
addition to the check for the EST flag it also checked if the vendor is Intel.
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
[ Removed the vendor checks entirely - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These are defined as static cpumask_var_t so if MAXSMP is not used,
they are cleared already. Avoid surprises when MAXSMP is enabled.
Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Take already available policy->cpuinfo.max_freq and get rid of acpi-cpufreq
specific max_freq variable.
This implies that P0 is always the highest frequency which should always
be true as ACPI spec says:
As a result, the zeroth entry describes the highest performance state
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
It turns out that 'smp_call_function_many()' doesn't work at all like
'smp_call_function_single()', and my change to Andrew's patch to use it
rather than a loop over all CPU's acpi-cpufreq doesn't work.
My bad.
'smp_call_function_many()' has two "features" (aka "documented bugs"):
(a) it needs to be called with preemption disabled, because it uses
smp_processor_id() without guarding the CPU lookup with 'get_cpu()'
and 'put_cpu()' like the 'single' variant does.
(b) even if the current CPU is part of the CPU mask, it won't do the
call on that CPU.
Still, we're better off trying to use 'smp_call_function_many()' than
looping over CPU's, since it at least in theory allows us to use a
broadcast IPI and do it all in parallel. So let's just work around the
silly semantic bugs in that function.
Reported-and-tested-by: Ali Gholami Rudi <ali@rudi.ir>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We ended up incorrectly using '&cur' instead of '&readin' in the
work_on_cpu() -> smp_call_function_single() transformation in commit
01599fca67 ("cpufreq: use
smp_call_function_[single|many]() in acpi-cpufreq.c").
Andrew explains:
"OK, the acpi tree went and had conflicting changes merged into it after
I'd written the patch and it appears that I incorrectly reverted part
of 18b2646fe3 while fixing the resulting
rejects.
Switching it to `readin' looks correct."
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Atttempting to rid us of the problematic work_on_cpu(). Just use
smp_call_fuction_single() here.
This repairs a 10% sysbench(oltp)+mysql regression which Mike reported,
due to
commit 6b44003e5c
Author: Andrew Morton <akpm@linux-foundation.org>
Date: Thu Apr 9 09:50:37 2009 -0600
work_on_cpu(): rewrite it to create a kernel thread on demand
It seems that the kernel calls these acpi-cpufreq functions at a quite
high frequency.
Valdis Kletnieks also reports that this causes 70-90 forks per second on
his hardware.
Cc: Valdis.Kletnieks@vt.edu
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Acked-by: Dave Jones <davej@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mike Galbraith <efault@gmx.de>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
[ Made it use smp_call_function_many() instead of looping over cpu's
with smp_call_function_single() - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Do not write zeroes to APERF and MPERF by ondemand governor. With this
change, other users can share these MSRs for reads.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Change structure name to make the code cleaner and simpler. No
functionality change in this patch.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Some BIOSes report very high frequency transition latency which are plainly
wrong on CPus that can change frequency using native MSR interface.
One such system is IBM T42 (2327-8ZU) as reported by Owen Taylor and
Rik van Riel.
cpufreq_ondemand driver uses this transition latency to come up with a
reasonable sampling interval to sample CPU usage and with such high
latency value, ondemand sampling interval ends up being very high
(0.5 sec, in this particular case), resulting in performance impact due to
slow response to increasing frequency.
Fix it by capping-off the transition latency to 20uS for native MSR based
frequency transitions.
mjg: We've confirmed that this also helps on the X31
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Impact: cleanup
There are two allocated per-cpu accessor macros with almost identical
spelling. The original and far more popular is per_cpu_ptr (44
files), so change over the other 4 files.
tj: kill percpu_ptr() and update UP too
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: mingo@redhat.com
Cc: lenb@kernel.org
Cc: cpufreq@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Convert the c/p state "power" tracer to use tracepoints. Avoids a
function call when the tracer is disabled.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: cleanup
Move the power tracer headers to trace/power.h to keep ftrace.h and power bits
more easy to maintain as separated topics.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
-tip testing found this crash:
> [ 35.258515] calling acpi_cpufreq_init+0x0/0x127 @ 1
> [ 35.264127] BUG: unable to handle kernel NULL pointer dereference at (null)
> [ 35.267554] IP: [<ffffffff80478092>] __bitmap_intersects+0x48/0x73
> [ 35.267554] PGD 0
> [ 35.267554] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c is still broken: there's no
allocation of the variable mask, so we pass in an uninitialized cmd.mask
field to drv_read(), which then passes it to the scheduler which then
crashes ...
Switch it over to the much simpler constant-cpumask-pointers approach.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: use new work_on_cpu function to reduce stack usage
Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().
Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.
Note: This patch basically reverts 50c668d6 which reverted 7503bfba, now
that the work_on_cpu() function is more stable.
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Dieter Ries <clip2@gmx.de>
Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <cpufreq@vger.kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: use new work_on_cpu function to reduce stack usage
Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().
Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.
Note: This patch basically reverts 50c668d6 which reverted 7503bfba, now
that the work_on_cpu() function is more stable.
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Dieter Ries <clip2@gmx.de>
Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <cpufreq@vger.kernel.org>
-tip testing found this crash:
> [ 35.258515] calling acpi_cpufreq_init+0x0/0x127 @ 1
> [ 35.264127] BUG: unable to handle kernel NULL pointer dereference at (null)
> [ 35.267554] IP: [<ffffffff80478092>] __bitmap_intersects+0x48/0x73
> [ 35.267554] PGD 0
> [ 35.267554] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c is still broken: there's no
allocation of the variable mask, so we pass in an uninitialized cmd.mask
field to drv_read(), which then passes it to the scheduler which then
crashes ...
Switch it over to the much simpler constant-cpumask-pointers approach.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix potential boot crash on MAXSMP
Remove code left over by:
50c668d: Revert "cpumask: use work_on_cpu in acpi-cpufreq.c for drv_read
That cmd.cpumask is not allocated anymore. No impact on default !MAXSMP
kernels.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit 7503bfbae8.
Dieter Ries reported bootup soft-hangs and bisected it back to
this commit, and reverting this commit gave him a working system.
The commit introduces work_on_cpu() use into the cpufreq code,
but that is subtly problematic from a lock hierarchy POV: the
hotplug-cpu lock is an highlevel lock that is taken before
lowlevel locks, and in this codepath we are called with the
policy lock taken.
Dieter did not have lockdep enabled so we dont have a nice stack
trace proof for this, but using work_on_cpu() in such a lowlevel
place certainly looks wrong, so we revert the patch.
work_on_cpu() needs to be reworked to be more generally usable.
Reported-by: Dieter Ries <clip2@gmx.de>
Tested-by: Dieter Ries <clip2@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: use new cpumask API to reduce stack usage
Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for read_measured_perf_ctrs().
Basically splits off the work function from get_measured_perf which is
run on the designated cpu. Moves definition of struct perf_cur out of
function local namespace, and is used as the work function argument.
References in get_measured_perf use values in the perf_cur struct.
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: use new cpumask API to reduce stack usage
Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().
Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, reduce stack usage, use new cpumask API.
Replace the cpumask_t in struct drv_cmd with a cpumask_var_t. Remove unneeded
online_policy_cpus cpumask_t in acpi_cpufreq_target. Update refs to use
new cpumask API.
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: use new cpumask API to reduce memory usage
This is part of an effort to reduce structure sizes for machines
configured with large NR_CPUS. cpumask_t gets replaced by
cpumask_var_t, which is either struct cpumask[1] (small NR_CPUS) or
struct cpumask * (large NR_CPUS).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Reduce inter-node memory traffic.
Reduces inter-node memory traffic (offloading the global system bus)
by allocating referenced struct cpumasks on the same node as the
referring struct.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Reduce memory usage, use new API.
This is part of an effort to reduce structure sizes for machines
configured with large NR_CPUS. cpumask_t gets replaced by
cpumask_var_t, which is either struct cpumask[1] (small NR_CPUS) or
struct cpumask * (large NR_CPUS).
(Changes to powernow-k* by <travis>.)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: new "power-tracer" ftrace plugin
This patch adds a C/P-state ftrace plugin that will generate
detailed statistics about the C/P-states that are being used,
so that we can look at detailed decisions that the C/P-state
code is making, rather than the too high level "average"
that we have today.
An example way of using this is:
mount -t debugfs none /sys/kernel/debug
echo cstate > /sys/kernel/debug/tracing/current_tracer
echo 1 > /sys/kernel/debug/tracing/tracing_enabled
sleep 1
echo 0 > /sys/kernel/debug/tracing/tracing_enabled
cat /sys/kernel/debug/tracing/trace | perl scripts/trace/cstate.pl > out.svg
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a cpu parameter to __cpufreq_driver_getavg(). This is needed for software
cpufreq coordination where policy->cpu may not be same as the CPU on which we
want to getavg frequency.
A follow-on patch will use this parameter to getavg freq from all cpus
in policy->cpus.
Change since last patch. Fix the offline/online and suspend/resume
oops reported by Youquan Song <youquan.song@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
add error handling for cpufreq_register_driver() error
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: cpufreq@lists.linux.org.uk
Signed-off-by: Dave Jones <davej@redhat.com>
