There is no possibility of any race on updating last_index, trans_table or
total_trans as these are updated only by cpufreq_stat_notifier_trans() which
will be called sequentially.
The only place where locking is still relevant is: cpufreq_stats_update(), which
updates time_in_state and last_time. This can be called by two thread in
parallel, that may result in races.
The two threads being:
- sysfs read of time_in_state
- and frequency transition that calls cpufreq_stat_notifier_trans().
Remove locking from the first case mentioned above.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We need to call cpufreq_stats_update() to update 'time_in_state' for the last
frequency. This is achieved by calling it from cpufreq_stat_notifier_trans(),
which is called after frequency transition.
But if we detect that the cpu's frequency haven't really changed and its a false
POSTCHANGE notification, we don't really need to update time_in_state.
It wouldn't cause any harm in calling cpufreq_stats_update() but we can avoid
calling it here and call it when the frequency really changes. The result will
be the same but more efficient.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq_stats_update() updates time_in_state and nothing else. It should ideally
be updated only in two cases:
- User requested for the current value of time_in_state.
- We have switched states and so need to update time for the last state.
Currently, we are also doing this while user asks for the transition table of
frequencies. It wouldn't do any harm, but no good as well. Its useless here.
Remove it.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
'time_in_state' can't be NULL if 'stats' is valid. These are allocated together
and only if time_in_state is allocated successfully, we update policy->stats.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Userspace is free to read value of any file from cpufreq/stats directory once
they are created. __cpufreq_stats_create_table() is creating the sysfs files
first and then allocating resources for them. Though it would be quite difficult
to trigger the racy situation here, but for the sake of keeping sensible code
lets create sysfs entries only after we are ready to go.
This also does some makeup to the routine to make it look better.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
'cpu' field of struct cpufreq_stats isn't used anymore and so can be dropped.
This change makes cpufreq_stats_update_policy_cpu() empty and so that is removed
as well.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently we name objects of 'struct cpufreq_stats' as 'stat' and 'stats'.
Use 'stats' to make it consistent.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All CPUs sharing a cpufreq policy share stats too. For this reason,
add a stats pointer to struct cpufreq_policy and drop per-CPU variable
cpufreq_stats_table used for accessing cpufreq stats so as to reduce
code complexity.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is better to pass a struct cpufreq_stats pointer to cpufreq_stats_update()
instead of a CPU number, because that's all it needs.
Even if we pass a cpu number to cpufreq_stats_update(), it reads the per-cpu
variable to get 'stats' out of it. So we are doing these operations
unnecessarily:
- First getting the cpu number to pass to cpufreq_stats_update(), stat->cpu.
- And then getting stats from the cpu, per_cpu(cpufreq_stats_table, cpu).
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
While we allocate stats, we do need to check if freq-table is present
or not as we need to use it then. But while freeing stats, all we need
to know is if stats holds a valid pointer value. There is no use of
testing if cpufreq table is present or not.
Don't check it.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
'cur_time' is defined in the first line and is then assigned a value
in the next line. Initialize it while defining it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It was never used, but is there since the first commit. Remove it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__cpufreq_stats_create_table() is called from:
- cpufreq notifier on creation of a new policy. Stats will always be
NULL here.
- cpufreq_stats_init() for all CPUs as cpufreq-stats might have been
initialized after cpufreq driver. For any policy, 'stats' will be
NULL for the first CPU only and will be valid for all other CPUs
managed by the same policy.
While we return for other CPUs, we don't return the right error value.
It's not that we would fail with -EBUSY. But generally, this is what
these return values mean:
- EBUSY: we are busy right now, try again. And the retry attempt might
be immediate.
- EEXIST: We already have what you are trying to create and there is no
need to create it again, and so no more tries are required.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The MODULE_DESCRIPTION() string is just too long and then is broken into
multiple lines just to make checkpatch happy.
Rewrite it to make it more precise.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq core now supports the cpufreq_for_each_entry and
cpufreq_for_each_valid_entry macros helpers for iteration over the
cpufreq_frequency_table, so use them.
It should have no functional changes.
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Device PM QoS support for latency tolerance constraints on systems with
hardware interfaces allowing such constraints to be specified. That is
necessary to prevent hardware-driven power management from becoming
overly aggressive on some systems and to prevent power management
features leading to excessive latencies from being used in some cases.
- Consolidation of the handling of ACPI hotplug notifications for device
objects. This causes all device hotplug notifications to go through
the root notify handler (that was executed for all of them anyway
before) that propagates them to individual subsystems, if necessary,
by executing callbacks provided by those subsystems (those callbacks
are associated with struct acpi_device objects during device
enumeration). As a result, the code in question becomes both smaller
in size and more straightforward and all of those changes should not
affect users.
- ACPICA update, including fixes related to the handling of _PRT in cases
when it is broken and the addition of "Windows 2013" to the list of
supported "features" for _OSI (which is necessary to support systems
that work incorrectly or don't even boot without it). Changes from
Bob Moore and Lv Zheng.
- Consolidation of ACPI _OST handling from Jiang Liu.
- ACPI battery and AC fixes allowing unusual system configurations to
be handled by that code from Alexander Mezin.
- New device IDs for the ACPI LPSS driver from Chiau Ee Chew.
- ACPI fan and thermal optimizations related to system suspend and resume
from Aaron Lu.
- Cleanups related to ACPI video from Jean Delvare.
- Assorted ACPI fixes and cleanups from Al Stone, Hanjun Guo, Lan Tianyu,
Paul Bolle, Tomasz Nowicki.
- Intel RAPL (Running Average Power Limits) driver cleanups from Jacob Pan.
- intel_pstate fixes and cleanups from Dirk Brandewie.
- cpufreq fixes related to system suspend/resume handling from Viresh Kumar.
- cpufreq core fixes and cleanups from Viresh Kumar, Stratos Karafotis,
Saravana Kannan, Rashika Kheria, Joe Perches.
- cpufreq drivers updates from Viresh Kumar, Zhuoyu Zhang, Rob Herring.
- cpuidle fixes related to the menu governor from Tuukka Tikkanen.
- cpuidle fix related to coupled CPUs handling from Paul Burton.
- Asynchronous execution of all device suspend and resume callbacks,
except for ->prepare and ->complete, during system suspend and resume
from Chuansheng Liu.
- Delayed resuming of runtime-suspended devices during system suspend for
the PCI bus type and ACPI PM domain.
- New set of PM helper routines to allow device runtime PM callbacks to
be used during system suspend and resume more easily from Ulf Hansson.
- Assorted fixes and cleanups in the PM core from Geert Uytterhoeven,
Prabhakar Lad, Philipp Zabel, Rashika Kheria, Sebastian Capella.
- devfreq fix from Saravana Kannan.
/
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Merge tag 'pm+acpi-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
"The majority of this material spent some time in linux-next, some of
it even several weeks. There are a few relatively fresh commits in
it, but they are mostly fixes and simple cleanups.
ACPI took the lead this time, both in terms of the number of commits
and the number of modified lines of code, cpufreq follows and there
are a few changes in the PM core and in cpuidle too.
A new feature that already got some LWN.net's attention is the device
PM QoS extension allowing latency tolerance requirements to be
propagated from leaf devices to their ancestors with hardware
interfaces for specifying latency tolerance. That should help systems
with hardware-driven power management to avoid going too far with it
in cases when there are latency tolerance constraints.
There also are some significant changes in the ACPI core related to
the way in which hotplug notifications are handled. They affect PCI
hotplug (ACPIPHP) and the ACPI dock station code too. The bottom line
is that all those notification now go through the root notify handler
and are propagated to the interested subsystems by means of callbacks
instead of having to install a notify handler for each device object
that we can potentially get hotplug notifications for.
In addition to that ACPICA will now advertise "Windows 2013"
compatibility for _OSI, because some systems out there don't work
correctly if that is not done (some of them don't even boot).
On the system suspend side of things, all of the device suspend and
resume callbacks, except for ->prepare() and ->complete(), are now
going to be executed asynchronously as that turns out to speed up
system suspend and resume on some platforms quite significantly and we
have a few more optimizations in that area.
Apart from that, there are some new device IDs and fixes and cleanups
all over. In particular, the system suspend and resume handling by
cpufreq should be improved and the cpuidle menu governor should be a
bit more robust now.
Specifics:
- Device PM QoS support for latency tolerance constraints on systems
with hardware interfaces allowing such constraints to be specified.
That is necessary to prevent hardware-driven power management from
becoming overly aggressive on some systems and to prevent power
management features leading to excessive latencies from being used
in some cases.
- Consolidation of the handling of ACPI hotplug notifications for
device objects. This causes all device hotplug notifications to go
through the root notify handler (that was executed for all of them
anyway before) that propagates them to individual subsystems, if
necessary, by executing callbacks provided by those subsystems
(those callbacks are associated with struct acpi_device objects
during device enumeration). As a result, the code in question
becomes both smaller in size and more straightforward and all of
those changes should not affect users.
- ACPICA update, including fixes related to the handling of _PRT in
cases when it is broken and the addition of "Windows 2013" to the
list of supported "features" for _OSI (which is necessary to
support systems that work incorrectly or don't even boot without
it). Changes from Bob Moore and Lv Zheng.
- Consolidation of ACPI _OST handling from Jiang Liu.
- ACPI battery and AC fixes allowing unusual system configurations to
be handled by that code from Alexander Mezin.
- New device IDs for the ACPI LPSS driver from Chiau Ee Chew.
- ACPI fan and thermal optimizations related to system suspend and
resume from Aaron Lu.
- Cleanups related to ACPI video from Jean Delvare.
- Assorted ACPI fixes and cleanups from Al Stone, Hanjun Guo, Lan
Tianyu, Paul Bolle, Tomasz Nowicki.
- Intel RAPL (Running Average Power Limits) driver cleanups from
Jacob Pan.
- intel_pstate fixes and cleanups from Dirk Brandewie.
- cpufreq fixes related to system suspend/resume handling from Viresh
Kumar.
- cpufreq core fixes and cleanups from Viresh Kumar, Stratos
Karafotis, Saravana Kannan, Rashika Kheria, Joe Perches.
- cpufreq drivers updates from Viresh Kumar, Zhuoyu Zhang, Rob
Herring.
- cpuidle fixes related to the menu governor from Tuukka Tikkanen.
- cpuidle fix related to coupled CPUs handling from Paul Burton.
- Asynchronous execution of all device suspend and resume callbacks,
except for ->prepare and ->complete, during system suspend and
resume from Chuansheng Liu.
- Delayed resuming of runtime-suspended devices during system suspend
for the PCI bus type and ACPI PM domain.
- New set of PM helper routines to allow device runtime PM callbacks
to be used during system suspend and resume more easily from Ulf
Hansson.
- Assorted fixes and cleanups in the PM core from Geert Uytterhoeven,
Prabhakar Lad, Philipp Zabel, Rashika Kheria, Sebastian Capella.
- devfreq fix from Saravana Kannan"
* tag 'pm+acpi-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits)
PM / devfreq: Rewrite devfreq_update_status() to fix multiple bugs
PM / sleep: Correct whitespace errors in <linux/pm.h>
intel_pstate: Set core to min P state during core offline
cpufreq: Add stop CPU callback to cpufreq_driver interface
cpufreq: Remove unnecessary braces
cpufreq: Fix checkpatch errors and warnings
cpufreq: powerpc: add cpufreq transition latency for FSL e500mc SoCs
MAINTAINERS: Reorder maintainer addresses for PM and ACPI
PM / Runtime: Update runtime_idle() documentation for return value meaning
video / output: Drop display output class support
fujitsu-laptop: Drop unneeded include
acer-wmi: Stop selecting VIDEO_OUTPUT_CONTROL
ACPI / gpu / drm: Stop selecting VIDEO_OUTPUT_CONTROL
ACPI / video: fix ACPI_VIDEO dependencies
cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE}
cpufreq: Do not allow ->setpolicy drivers to provide ->target
cpufreq: arm_big_little: set 'physical_cluster' for each CPU
cpufreq: arm_big_little: make vexpress driver depend on bL core driver
ACPI / button: Add ACPI Button event via netlink routine
ACPI: Remove duplicate definitions of PREFIX
...
The architectures that override cputime_t (s390, ppc) don't provide
any version of nsecs_to_cputime(). Indeed this cputime_t implementation
by backend only happens when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y under
which the core code doesn't make any use of nsecs_to_cputime().
At least for now.
We are going to make a broader use of it so lets provide a default
version with a per usecs granularity. It should be good enough for most
usecases.
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
cpufreq_frequency_get_table() is called from all callers of
__cpufreq_stats_create_table(). So, move it inside.
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Remove sysfs group if __cpufreq_stats_create_table() fails after creating
one.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__cpufreq_stats_create_table always gets pass the valid and real policy
struct. So, there's no need to call cpufreq_cpu_get() to get the policy
again.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When cpufreq_stats is compiled in as a module, cpufreq driver would
have already been registered. And so the CPUFREQ_CREATE_POLICY
notifiers wouldn't be called for it. Hence no sysfs entries for stats. :(
This patch calls cpufreq_stats_create_table() for each online CPU from
cpufreq_stats_init() and so if policy is already created for CPUx then
we will register sysfs stats for it.
When its not compiled as module, we will return early as policy wouldn't
be found for any of the CPUs.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We don't have code paths now where we need to do these two things
separately, so it is better do them in a single routine. Just as
they are allocated in a single routine.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Either CPUs are hot-unplugged or suspend/resume occurs, cpufreq core
will send notifications to cpufreq-stats and stats structure and sysfs
entries would be correctly handled..
And so we don't actually need hotcpu notifiers in cpufreq-stats anymore.
We were only handling cpu hot-unplug events here and that are already
taken care of by POLICY notifiers.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are several problems with cpufreq stats in the way it handles
cpufreq_unregister_driver() and suspend/resume..
- We must not lose data collected so far when suspend/resume happens
and so stats directories must not be removed/allocated during these
operations, which is done currently.
- cpufreq_stat has registered notifiers with both cpufreq and hotplug.
It adds sysfs stats directory with a cpufreq notifier: CPUFREQ_NOTIFY
and removes this directory with a notifier from hotplug core.
In case cpufreq_unregister_driver() is called (on rmmod cpufreq driver),
stats directories per cpu aren't removed as CPUs are still online. The
only call cpufreq_stats gets is cpufreq_stats_update_policy_cpu() for
all CPUs except the last of each policy. And pointer to stat information
is stored in the entry for last CPU in the per-cpu cpufreq_stats_table.
But policy structure would be freed inside cpufreq core and so that will
result in memory leak inside cpufreq stats (as we are never freeing
memory for stats).
Now if we again insert the module cpufreq_register_driver() will be
called and we will again allocate stats data and put it on for first
CPU of every policy. In case we only have a single CPU per policy, we
will return with a error from cpufreq_stats_create_table() due to this
code:
if (per_cpu(cpufreq_stats_table, cpu))
return -EBUSY;
And so probably cpufreq stats directory would not show up anymore (as
it was added inside last policies->kobj which doesn't exist anymore).
I haven't tested it, though. Also the values in stats files wouldn't
be refreshed as we are using the earlier stats structure.
- CPUFREQ_NOTIFY is called from cpufreq_set_policy() which is called for
scenarios where we don't really want cpufreq_stat_notifier_policy() to get
called. For example whenever we are changing anything related to a policy:
min/max/current freq, etc. cpufreq_set_policy() is called and so cpufreq
stats is notified. Where we don't do any useful stuff other than simply
returning with -EBUSY from cpufreq_stats_create_table(). And so this
isn't the right notifier that cpufreq stats..
Due to all above reasons this patch does following changes:
- Add new notifiers CPUFREQ_CREATE_POLICY and CPUFREQ_REMOVE_POLICY,
which are only called when policy is created/destroyed. They aren't
called for suspend/resume paths..
- Use these notifiers in cpufreq_stat_notifier_policy() to create/destory
stats sysfs entries. And so cpufreq_unregister_driver() or suspend/resume
shouldn't be a problem for cpufreq_stats.
- Return early from cpufreq_stat_cpu_callback() for suspend/resume sequence,
so that we don't free stats structure.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The time spent by a CPU under a given frequency is stored in jiffies unit
in the cpu var cpufreq_stats_table->time_in_state[i], i being the index of
the frequency.
This is what is displayed in the following file on the right column:
cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
2301000 19835820
2300000 3172
[...]
Now cpufreq converts this jiffies unit delta to clock_t before returning it
to the user as in the above file. And that conversion is achieved using the API
cputime64_to_clock_t().
Although it accidentally works on traditional tick based cputime accounting, where
cputime_t maps directly to jiffies, it doesn't work with other types of cputime
accounting such as CONFIG_VIRT_CPU_ACCOUNTING_* where cputime_t can map to nsecs
or any granularity preffered by the architecture.
For example we get a buggy zero delta on full dyntick configurations:
cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
2301000 0
2300000 0
[...]
Fix this with using the proper jiffies_64_t to clock_t conversion.
Reported-and-tested-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Chapter 14 of Documentation/CodingStyle says:
The preferred form for passing a size of a struct is the following:
p = kmalloc(sizeof(*p), ...);
The alternative form where struct name is spelled out hurts
readability and introduces an opportunity for a bug when the pointer
variable type is changed but the corresponding sizeof that is passed
to a memory allocator is not.
This wasn't followed consistently in drivers/cpufreq, let's make it
more consistent by always following this rule.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
They are called policy, cur_policy, new_policy, data, etc. Just call
them policy wherever possible.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch addresses the following issues in the header files in the
cpufreq core:
- Include headers in ascending order, so that we don't add same
many times by mistake.
- <asm/> must be included after <linux/>, so that they override
whatever they need to.
- Remove unnecessary includes.
- Don't include files already included by cpufreq.h or
cpufreq_governor.h.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Now that we have the infrastructure to perform a light-weight init/tear-down,
use that in the cpufreq CPU hotplug notifier when invoked from the
suspend/resume path.
This also ensures that the file permissions of the cpufreq sysfs files are
preserved across suspend/resume, something which commit a66b2e (cpufreq:
Preserve sysfs files across suspend/resume) originally intended to do, but
had to be reverted due to other problems.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The call to cpufreq_update_policy() is placed in the CPU hotplug callback
of cpufreq_stats, which has a higher priority than the CPU hotplug callback
of cpufreq-core. As a result, during CPU_ONLINE/CPU_ONLINE_FROZEN, we end up
calling cpufreq_update_policy() *before* calling cpufreq_add_dev() !
And for uninitialized CPUs, it just returns silently, not doing anything.
To add to that, cpufreq_stats is not even the right place to call
cpufreq_update_policy() to begin with. The cpufreq core ought to handle
this in its own callback, from an elegance/relevance perspective.
So move the invocation of cpufreq_update_policy() to cpufreq_cpu_callback,
and place it *after* cpufreq_add_dev().
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Two cpufreq commits from the 3.10 cycle introduced regressions.
The first of them was buggy (it did way much more than it needed
to do) and the second one attempted to fix an issue introduced by
the first one. Fixes from Srivatsa S Bhat revert both.
- If autosleep triggers during system shutdown and the shutdown
callbacks of some device drivers have been called already, it may
crash the system. Fix from Liu Shuo prevents that from happening
by making try_to_suspend() check system_state.
- The ACPI memory hotplug driver doesn't clear its driver_data on
errors which may cause a NULL poiter dereference to happen later.
Fix from Toshi Kani.
- The ACPI namespace scanning code should not try to attach scan
handlers to device objects that have them already, which may confuse
things quite a bit, and it should rescan the whole namespace branch
starting at the given node after receiving a bus check notify event
even if the device at that particular node has been discovered
already. Fixes from Rafael J Wysocki.
- New ACPI video blacklist entry for a system whose initial backlight
setting from the BIOS doesn't make sense. From Lan Tianyu.
- Garbage string output avoindance for ACPI PNP from Liu Shuo.
- Two Kconfig fixes for issues introduced recently in the s3c24xx
cpufreq driver (when moving the driver to drivers/cpufreq) from
Paul Bolle.
- Trivial comment fix in pm_wakeup.h from Chanwoo Choi.
/
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Merge tag 'pm+acpi-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI fixes from Rafael Wysocki:
"These are fixes collected over the last week, most importnatly two
cpufreq reverts fixing regressions introduced in 3.10, an autoseelp
fix preventing systems using it from crashing during shutdown and two
ACPI scan fixes related to hotplug.
Specifics:
- Two cpufreq commits from the 3.10 cycle introduced regressions.
The first of them was buggy (it did way much more than it needed to
do) and the second one attempted to fix an issue introduced by the
first one. Fixes from Srivatsa S Bhat revert both.
- If autosleep triggers during system shutdown and the shutdown
callbacks of some device drivers have been called already, it may
crash the system. Fix from Liu Shuo prevents that from happening
by making try_to_suspend() check system_state.
- The ACPI memory hotplug driver doesn't clear its driver_data on
errors which may cause a NULL poiter dereference to happen later.
Fix from Toshi Kani.
- The ACPI namespace scanning code should not try to attach scan
handlers to device objects that have them already, which may
confuse things quite a bit, and it should rescan the whole
namespace branch starting at the given node after receiving a bus
check notify event even if the device at that particular node has
been discovered already. Fixes from Rafael J Wysocki.
- New ACPI video blacklist entry for a system whose initial backlight
setting from the BIOS doesn't make sense. From Lan Tianyu.
- Garbage string output avoindance for ACPI PNP from Liu Shuo.
- Two Kconfig fixes for issues introduced recently in the s3c24xx
cpufreq driver (when moving the driver to drivers/cpufreq) from
Paul Bolle.
- Trivial comment fix in pm_wakeup.h from Chanwoo Choi"
* tag 'pm+acpi-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / video: ignore BIOS initial backlight value for Fujitsu E753
PNP / ACPI: avoid garbage in resource name
cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regression
cpufreq: s3c24xx: fix "depends on ARM_S3C24XX" in Kconfig
cpufreq: s3c24xx: rename CONFIG_CPU_FREQ_S3C24XX_DEBUGFS
PM / Sleep: Fix comment typo in pm_wakeup.h
PM / Sleep: avoid 'autosleep' in shutdown progress
cpufreq: Revert commit a66b2e to fix suspend/resume regression
ACPI / memhotplug: Fix a stale pointer in error path
ACPI / scan: Always call acpi_bus_scan() for bus check notifications
ACPI / scan: Do not try to attach scan handlers to devices having them
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
This removes all the drivers/cpufreq uses of the __cpuinit macros
from all C files.
[1] https://lkml.org/lkml/2013/5/20/589
[v2: leave 2nd lines of args misaligned as requested by Viresh]
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
commit a66b2e (cpufreq: Preserve sysfs files across suspend/resume)
has unfortunately caused several things in the cpufreq subsystem to
break subtly after a suspend/resume cycle.
The intention of that patch was to retain the file permissions of the
cpufreq related sysfs files across suspend/resume. To achieve that,
the commit completely removed the calls to cpufreq_add_dev() and
__cpufreq_remove_dev() during suspend/resume transitions. But the
problem is that those functions do 2 kinds of things:
1. Low-level initialization/tear-down that are critical to the
correct functioning of cpufreq-core.
2. Kobject and sysfs related initialization/teardown.
Ideally we should have reorganized the code to cleanly separate these
two responsibilities, and skipped only the sysfs related parts during
suspend/resume. Since we skipped the entire callbacks instead (which
also included some CPU and cpufreq-specific critical components),
cpufreq subsystem started behaving erratically after suspend/resume.
So revert the commit to fix the regression. We'll revisit and address
the original goal of that commit separately, since it involves quite a
bit of careful code reorganization and appears to be non-trivial.
(While reverting the commit, note that another commit f51e1eb
(cpufreq: Fix cpufreq regression after suspend/resume) already
reverted part of the original set of changes. So revert only the
remaining ones).
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Paul Bolle <pebolle@tiscali.nl>
Cc: 3.10+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Toralf Förster reported that the cpufreq ondemand governor behaves erratically
(doesn't scale well) after a suspend/resume cycle. The problem was that the
cpufreq subsystem's idea of the cpu frequencies differed from the actual
frequencies set in the hardware after a suspend/resume cycle. Toralf bisected
the problem to commit a66b2e5 (cpufreq: Preserve sysfs files across
suspend/resume).
Among other (harmless) things, that commit skipped the call to
cpufreq_update_policy() in the resume path. But cpufreq_update_policy() plays
an important role during resume, because it is responsible for checking if
the BIOS changed the cpu frequencies behind our back and resynchronize the
cpufreq subsystem's knowledge of the cpu frequencies, and update them
accordingly.
So, restore the call to cpufreq_update_policy() in the resume path to fix
the cpufreq regression.
Reported-and-tested-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: 3.10+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There were a few noticeable formatting issues in core cpufreq code.
This cleans them up to make code look better. The changes include:
- Whitespace cleanup.
- Rearrangements of code.
- Multiline comments fixes.
- Formatting changes to fit 80 columns.
Copyright information in cpufreq.c is also updated to include my name
for 2013.
[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The file permissions of cpufreq per-cpu sysfs files are not preserved
across suspend/resume because we internally go through the CPU
Hotplug path which reinitializes the file permissions on CPU online.
But the user is not supposed to know that we are using CPU hotplug
internally within suspend/resume (IOW, the kernel should not silently
wreck the user-set file permissions across a suspend cycle).
Therefore, we need to preserve the file permissions as they are
across suspend/resume.
The simplest way to achieve that is to just not touch the sysfs files
at all - ie., just ignore the CPU hotplug notifications in the
suspend/resume path (_FROZEN) in the cpufreq hotplug callback.
Reported-by: Robert Jarzmik <robert.jarzmik@intel.com>
Reported-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In cpufreq_stats_free_sysfs() we aren't balancing calls to
cpufreq_cpu_get() with cpufreq_cpu_put(). This will never let us have
ref count to policy->kobj as zero.
We will get a hang if somehow cpufreq_driver_unregister() is called.
And that can happen when we compile our driver as module and
insmod/rmmod it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The sysfs files for cpufreq_stats are created in cpufreq_stats_create_table()
called from cpufreq_stat_notifier_policy() when a policy is added to
the cpu. cpufreq_stats_create_table() will not be called if the
scaling driver does not export a frequency table to cpufreq. Use the
same fence on tear down.
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Macro "CPUFREQ_STATDEVICE_ATTR" is defined local to cpufreq_stats.c file and is
almost a copy of the generic version present in cpufreq.h file. Lets use the
generic version instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Implement a generic helper function policy_is_shared() to replace the
current dbs_sw_coordinated_cpus() at cpufreq level, so that it can be
used by code other than cpufreq governors.
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
__cpufreq_remove_dev() is called on multiple occasions: cpufreq_driver
unregister and cpu removals.
Current implementation of this routine is overly complex without much need. If
the cpu to be removed is the policy->cpu, we remove the policy first and add all
other cpus again from policy->cpus and then finally call __cpufreq_remove_dev()
again to remove the cpu to be deleted. Haahhhh..
There exist a simple solution to removal of a cpu:
- Simply use the old policy structure
- update its fields like: policy->cpu, etc.
- notify any users of cpufreq, which depend on changing policy->cpu
Hence this patch, which tries to implement the above theory. It is tested well
by myself on ARM big.LITTLE TC2 SoC, which has 5 cores (2 A15 and 3 A7). Both
A15's share same struct policy and all A7's share same policy structure.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch forces complete struct cpufreq_stats allocation for all cpus before
registering CPUFREQ_TRANSITION_NOTIFIER notifier, otherwise in some conditions
cpufreq_stat_notifier_trans() can be called in the middle of stats allocation,
in this case cpufreq_stats_table already exists, but stat->freq_table is NULL.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There were few sparse warnings due to mismatch of type on function arguments.
Two types were used u64 and cputime64_t. Both are actually u64, so use u64 only.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When system enters sleep, non-boot CPUs will be disabled.
Cpufreq stats sysfs is created when the CPU is up, but it is not
freed when the CPU is going down. This will cause memory leak.
Signed-off-by: xiaobing tu <xiaobing.tu@intel.com>
Signed-off-by: guifang tang <guifang.tang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (73 commits)
arm: fix up some samsung merge sysdev conversion problems
firmware: Fix an oops on reading fw_priv->fw in sysfs loading file
Drivers:hv: Fix a bug in vmbus_driver_unregister()
driver core: remove __must_check from device_create_file
debugfs: add missing #ifdef HAS_IOMEM
arm: time.h: remove device.h #include
driver-core: remove sysdev.h usage.
clockevents: remove sysdev.h
arm: convert sysdev_class to a regular subsystem
arm: leds: convert sysdev_class to a regular subsystem
kobject: remove kset_find_obj_hinted()
m86k: gpio - convert sysdev_class to a regular subsystem
mips: txx9_sram - convert sysdev_class to a regular subsystem
mips: 7segled - convert sysdev_class to a regular subsystem
sh: dma - convert sysdev_class to a regular subsystem
sh: intc - convert sysdev_class to a regular subsystem
power: suspend - convert sysdev_class to a regular subsystem
power: qe_ic - convert sysdev_class to a regular subsystem
power: cmm - convert sysdev_class to a regular subsystem
s390: time - convert sysdev_class to a regular subsystem
...
Fix up conflicts with 'struct sysdev' removal from various platform
drivers that got changed:
- arch/arm/mach-exynos/cpu.c
- arch/arm/mach-exynos/irq-eint.c
- arch/arm/mach-s3c64xx/common.c
- arch/arm/mach-s3c64xx/cpu.c
- arch/arm/mach-s5p64x0/cpu.c
- arch/arm/mach-s5pv210/common.c
- arch/arm/plat-samsung/include/plat/cpu.h
- arch/powerpc/kernel/sysfs.c
and fix up cpu_is_hotpluggable() as per Greg in include/linux/cpu.h
This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.
After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.
Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
So that we can clean up the header files and not be relying
on implicit includes from device.h ---> module.h
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
If the driver submitted an non-existing pol>cur value (say it
used the default initialized value of zero), when the cpufreq
stats tries to setup its initial values it incorrectly sets
stat->last_index to -1 (or 0xfffff...). And cpufreq_stats_update
tries to update at that index location and fails.
This can be caused by:
stat->last_index = freq_table_get_index(stat, policy->cur);
not finding the appropiate frequency in the table (b/c the policy->cur
is wrong) and we end up crashing. The fix however is
concentrated in the 'cpufreq_stats_update' as the last_index
(and old_index) are updated there. Which means it can reset
the last_index to -1 again and on the next iteration cause a crash.
Without this patch, the following crash is observed:
powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
.. snip..
Pid: 1, comm: swapper Not tainted 3.0.0-rc2 #45 MICRO-STAR INTERNATIONAL CO., LTD MS-7094/MS-7094
..snip..
Call Trace:
[<ffffffff81479248>] cpufreq_stat_notifier_trans+0x48/0x7c
[<ffffffff81095d68>] notifier_call_chain+0x32/0x5e
[<ffffffff81095e6b>] __srcu_notifier_call_chain+0x47/0x63
[<ffffffff81095e96>] srcu_notifier_call_chain+0xf/0x11
[<ffffffff81477e7a>] cpufreq_notify_transition+0x111/0x134
[<ffffffff8147b0d4>] powernowk8_target+0x53b/0x617
[<ffffffff8147723a>] __cpufreq_driver_target+0x2e/0x30
[<ffffffff8147a127>] cpufreq_governor_dbs+0x339/0x356
[<ffffffff81477394>] __cpufreq_governor+0xa8/0xe9
[<ffffffff81477525>] __cpufreq_set_policy+0x132/0x13e
[<ffffffff8147848d>] cpufreq_add_dev_interface+0x272/0x28c
Reported-by: Tobias Diedrich <ranma+xen@tdiedrich.de>
Tested-by: Tobias Diedrich <ranma+xen@tdiedrich.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dave Jones <davej@redhat.com>
cpufreq_stats leaves behind its sysfs entries, which causes a panic
when something stumbled across them.
(Discovered by unloading cpufreq_stats while powertop was loaded).
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: stable@kernel.org
