linux-stable.git/drivers/cpufreq, branch linux-2.6.33.y

CPUFREQ: Remove cpufreq_stats sysfs entries on module unload.

2011-06-23T22:28:41+00:00

commit 13f067537f34456443f61c950cd6dc37d1d5f3ee upstream.

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 
Signed-off-by: Greg Kroah-Hartman

Fix memory leak in cpufreq_stat

2011-06-23T22:28:33+00:00

commit 98586ed8b8878e10691203687e89a42fa3355300 upstream.

When a CPU is taken offline in an SMP system, cpufreq_remove_dev()
nulls out the per-cpu policy before cpufreq_stats_free_table() can
make use of it.  cpufreq_stats_free_table() then skips the
call to sysfs_remove_group(), leaving about 100 bytes of sysfs-related
memory unclaimed each time a CPU-removal occurs. Break up
cpu_stats_free_table into sysfs and table portions, and
call the sysfs portion early.

Signed-off-by: Steven Finney 
Signed-off-by: Dave Jones 
Signed-off-by: Greg Kroah-Hartman

CPU hotplug, re-create sysfs directory and symlinks

2011-06-23T22:28:33+00:00

commit 27ecddc2a9f99ce4ac9a59a0acd77f7100b6d034 upstream.

When we discover CPUs that are affected by each other's
frequency/voltage transitions, the first CPU gets a sysfs directory
created, and rest of the siblings get symlinks. Currently, when we
hotplug off only the first CPU, all of the symlinks and the sysfs
directory gets removed. Even though rest of the siblings are still
online and functional, they are orphaned, and no longer governed by
cpufreq.

This patch, given the above scenario, creates a sysfs directory for
the first sibling and symlinks for the rest of the siblings.

Please note the recursive call, it was rather too ugly to roll it
out. And the removal of redundant NULL setting (it is already taken
care of near the top of the function).

Signed-off-by: Jacob Shin 
Acked-by: Mark Langsdorf 
Reviewed-by: Thomas Renninger 
Signed-off-by: Dave Jones 
Signed-off-by: Greg Kroah-Hartman

revert "[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)"

2010-08-02T17:26:47+00:00

commit accd846698439ba18250e8fd5681af280446b853 upstream.

395913d0b1db37092ea3d9d69b832183b1dd84c5 ("[CPUFREQ] remove rwsem lock
from CPUFREQ_GOV_STOP call (second call site)") is not needed, because
there is no rwsem lock in cpufreq_ondemand and cpufreq_conservative
anymore.  Lock should not be released until the work done.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=1594

Signed-off-by: Andrej Gelenberg 
Cc: Mathieu Desnoyers 
Cc: Venkatesh Pallipadi 
Signed-off-by: Andrew Morton 
Acked-by: Mathieu Desnoyers 
Signed-off-by: Dave Jones 
Signed-off-by: Greg Kroah-Hartman

[CPUFREQ] Fix ondemand to not request targets outside policy limits

2010-01-13T15:55:16+00:00

Dominik said:
target_freq cannot be below policy->min or above policy->max.
If it were, the whole cpufreq subsystem is broken.

But (answer):
I think the "ondemand" governor can ask for a target frequency that is
below policy->min.
...
A patch such as below may be needed to sanitize the target frequency
requested by "ondemand". The "conservative" governor already has this check:

Signed-off-by: Thomas Renninger 
Signed-off-by: Dave Jones 

# diff -bur x/drivers/cpufreq/cpufreq_ondemand.c.orig y/drivers/cpufreq/cpufreq_ondemand.c

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2009-12-14T17:58:24+00:00

* '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

[ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface

2009-11-24T18:33:34+00:00

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 
CC: Len Brown 
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.net

Signed-off-by: Thomas Renninger 
Signed-off-by: Dave Jones

[CPUFREQ] make internal cpufreq_add_dev_* static

2009-11-24T18:33:34+00:00

No need to export these symbols; make them static.

	cpufreq_add_dev_policy
	cpufreq_add_dev_symlink
	cpufreq_add_dev_interface

Signed-off-by: Alex Chiang 
Signed-off-by: Dave Jones

[CPUFREQ] Use global sysfs cpufreq structure for conservative governor tunings

2009-11-24T18:33:34+00:00

Same adustments that have been added to the ondemand recently.

Signed-off-by: Thomas Renninger 
Signed-off-by: Dave Jones

[CPUFREQ] Fix stale cpufreq_cpu_governor pointer

2009-11-18T04:15:04+00:00

Dave,

Attached is an update of my patch against the cpufreq fixes branch.

Before applying the patch I compiled and booted the tree to see if the panic
was still there -- to my surprise it was not.  This is because of the conversion
of cpufreq_cpu_governor to a char[].

While the panic is kaput, the problem of stale data continues and my patch is
still valid.  It is possible to end up with the wrong governor after hotplug
events because CPUFREQ_DEFAULT_GOVERNOR is statically linked to a default,
while the cpu siblings may have had a different governor assigned by a user.

ie) the patch is still needed in order to keep the governors assigned
properly when hotplugging devices

Signed-off-by: Prarit Bhargava 
Signed-off-by: Dave Jones