12 Jan, 2012
1 commit
-
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: (23 commits)
[CPUFREQ] EXYNOS: Removed useless headers and codes
[CPUFREQ] EXYNOS: Make EXYNOS common cpufreq driver
[CPUFREQ] powernow-k8: Update copyright, maintainer and documentation information
[CPUFREQ] powernow-k8: Fix indexing issue
[CPUFREQ] powernow-k8: Avoid Pstate MSR accesses on systems supporting CPB
[CPUFREQ] update lpj only if frequency has changed
[CPUFREQ] cpufreq:userspace: fix cpu_cur_freq updation
[CPUFREQ] Remove wall variable from cpufreq_gov_dbs_init()
[CPUFREQ] EXYNOS4210: cpufreq code is changed for stable working
[CPUFREQ] EXYNOS4210: Update frequency table for cpu divider
[CPUFREQ] EXYNOS4210: Remove code about bus on cpufreq
[CPUFREQ] s3c64xx: Use pr_fmt() for consistent log messages
cpufreq: OMAP: fixup for omap_device changes, include
cpufreq: OMAP: fix freq_table leak
cpufreq: OMAP: put clk if cpu_init failed
cpufreq: OMAP: only supports OPP library
cpufreq: OMAP: dont support !freq_table
cpufreq: OMAP: deny initialization if no mpudev
cpufreq: OMAP: move clk name decision to init
cpufreq: OMAP: notify even with bad boot frequency
...
06 Jan, 2012
1 commit
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During scaling up of cpu frequency, loops_per_jiffy
is updated upon invoking PRECHANGE notifier.
If setting to new frequency fails in cpufreq driver,
lpj is left at incorrect value.Hence update lpj only if cpu frequency is changed,
i.e. upon invoking POSTCHANGE notifier.Penalty would be that during time period between
changing cpu frequency & invocation of POSTCHANGE
notifier, udelay(x) may not gurantee minimal delay
of 'x' us for frequency scaling up operation.Perhaps a better solution would be to define
CPUFREQ_ABORTCHANGE & handle accordingly, but then
it would be more intrusive (using ABORTCHANGE may
help drivers also; if any has registered notifier
and expect POST for a PRECHANGE, their needs can
be taken care using ABORT)Signed-off-by: Afzal Mohammed
Signed-off-by: Dave Jones
22 Dec, 2011
1 commit
-
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
Cc: Hans-Christian Egtvedt
Cc: Tony Luck
Cc: Fenghua Yu
Cc: Arnd Bergmann
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: Paul Mundt
Cc: "David S. Miller"
Cc: Chris Metcalf
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: "H. Peter Anvin"
Cc: Borislav Petkov
Cc: Tigran Aivazian
Cc: Len Brown
Cc: Zhang Rui
Cc: Dave Jones
Cc: Peter Zijlstra
Cc: Russell King
Cc: Andrew Morton
Cc: Arjan van de Ven
Cc: "Rafael J. Wysocki"
Cc: "Srivatsa S. Bhat"
Signed-off-by: Kay Sievers
Signed-off-by: Greg Kroah-Hartman
29 Jun, 2011
1 commit
-
This allows drivers and other code to get the max reported CPU frequency.
Initial use is for scaling ring frequency with GPU frequency in the i915
driver.Signed-off-by: Jesse Barnes
Signed-off-by: Keith Packard
04 May, 2011
3 commits
-
Since format string handling is part of request_module, there is no
need to construct the module name. As such, drop the redundant sprintf
and heap usage.Signed-off-by: Kees Cook
Signed-off-by: Dave Jones -
With dynamic debug having gained the capability to report debug messages
also during the boot process, it offers a far superior interface for
debug messages than the custom cpufreq infrastructure. As a first step,
remove the old cpufreq_debug_printk() function and replace it with a call
to the generic pr_debug() function.How can dynamic debug be used on cpufreq? You need a kernel which has
CONFIG_DYNAMIC_DEBUG enabled.To enabled debugging during runtime, mount debugfs and
$ echo -n 'module cpufreq +p' > /sys/kernel/debug/dynamic_debug/control
for debugging the complete "cpufreq" module. To achieve the same goal during
boot, appendddebug_query="module cpufreq +p"
as a boot parameter to the kernel of your choice.
For more detailled instructions, please see
Documentation/dynamic-debug-howto.txtSigned-off-by: Dominik Brodowski
Signed-off-by: Dave Jones -
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
Cc: stable@kernel.org
31 Mar, 2011
1 commit
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Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
24 Mar, 2011
1 commit
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The cpufreq subsystem uses sysdev suspend and resume for
executing cpufreq_suspend() and cpufreq_resume(), respectively,
during system suspend, after interrupts have been switched off on the
boot CPU, and during system resume, while interrupts are still off on
the boot CPU. In both cases the other CPUs are off-line at the
relevant point (either they have been switched off via CPU hotplug
during suspend, or they haven't been switched on yet during resume).
For this reason, although it may seem that cpufreq_suspend() and
cpufreq_resume() are executed for all CPUs in the system, they are
only called for the boot CPU in fact, which is quite confusing.To remove the confusion and to prepare for elimiating sysdev
suspend and resume operations from the kernel enirely, convernt
cpufreq to using a struct syscore_ops object for the boot CPU
suspend and resume and rename the callbacks so that their names
reflect their purpose. In addition, put some explanatory remarks
into their kerneldoc comments.Signed-off-by: Rafael J. Wysocki
17 Mar, 2011
1 commit
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None of the existing cpufreq drivers uses the second argument of
its .suspend() callback (which isn't useful anyway), so remove it.Signed-off-by: Rafael J. Wysocki
Signed-off-by: Dave Jones
02 Mar, 2011
1 commit
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cpufreq_register_driver sets cpufreq_driver to a structure owned (and
placed) in the caller's memory. If cpufreq policy fails in its ->init
function, sysdev_driver_register returns nonzero in
cpufreq_register_driver. Now, cpufreq_register_driver returns an error
without setting cpufreq_driver back to NULL.Usually cpufreq policy modules are unloaded because they propagate the
error to the module init function and return that.So a later access to any member of cpufreq_driver causes bugs like:
BUG: unable to handle kernel paging request at ffffffffa00270a0
IP: [] cpufreq_cpu_get+0x53/0xe0
PGD 1805067 PUD 1809063 PMD 1c3f90067 PTE 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/virtual/net/tun0/statistics/collisions
CPU 0
Modules linked in: ...
Pid: 5677, comm: thunderbird-bin Tainted: G W 2.6.38-rc4-mm1_64+ #1389 To be filled by O.E.M./To Be Filled By O.E.M.
RIP: 0010:[] [] cpufreq_cpu_get+0x53/0xe0
RSP: 0018:ffff8801aec37d98 EFLAGS: 00010086
RAX: 0000000000000202 RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffffffffa00270a0 RSI: 0000000000001000 RDI: ffffffff8199ece8
...
Call Trace:
[] cpufreq_quick_get+0x10/0x30
[] show_cpuinfo+0x2ab/0x300
[] seq_read+0xf2/0x3f0
[] ? __strncpy_from_user+0x33/0x60
[] proc_reg_read+0x6d/0xa0
[] vfs_read+0xc3/0x180
[] sys_read+0x4c/0x90
[] system_call_fastpath+0x16/0x1b
...It's all cause by weird fail path handling in cpufreq_register_driver.
To fix that, shuffle the code to do proper handling with gotos.Signed-off-by: Jiri Slaby
Signed-off-by: Dave Jones
04 Jan, 2011
1 commit
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Add these new power trace events:
power:cpu_idle
power:cpu_frequency
power:machine_suspendThe old C-state/idle accounting events:
power:power_start
power:power_endHave now a replacement (but we are still keeping the old
tracepoints for compatibility):power:cpu_idle
and
power:power_frequencyis replaced with:
power:cpu_frequencypower:machine_suspend is newly introduced.
Jean Pihet has a patch integrated into the generic layer
(kernel/power/suspend.c) which will make use of it.the type= field got removed from both, it was never
used and the type is differed by the event type itself.perf timechart userspace tool gets adjusted in a separate patch.
Signed-off-by: Thomas Renninger
Signed-off-by: Ingo Molnar
Acked-by: Arjan van de Ven
Acked-by: Jean Pihet
Cc: Arnaldo Carvalho de Melo
Cc: Peter Zijlstra
Cc: Linus Torvalds
Cc: rjw@sisk.pl
LKML-Reference:
Signed-off-by: Ingo Molnar
LKML-Reference:
22 Oct, 2010
1 commit
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Indent the body of for_each_cpu.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)//
@r disable braces4@
position p1,p2;
statement S1,S2;
@@(
if (...) { ... }
|
if (...) S1@p1 S2@p2
)@script:python@
p1 << r.p1;
p2 << r.p2;
@@if (p1[0].column == p2[0].column):
cocci.print_main("branch",p1)
cocci.print_secs("after",p2)
//Signed-off-by: Julia Lawall
Signed-off-by: Dave Jones
04 Aug, 2010
5 commits
-
This patch fixes up a brace warning found by the checkpatch.pl tool
Signed-off-by: Neal Buckendahl
Signed-off-by: Dave Jones -
and fix the broken case if a core's frequency depends on others.
trace_power_frequency was only implemented in a rather ungeneric way
in acpi-cpufreq driver's target() function only.
-> Move the call to trace_power_frequency to
cpufreq.c:cpufreq_notify_transition() where CPUFREQ_POSTCHANGE
notifier is triggered.
This will support power frequency tracing by all cpufreq driverstrace_power_frequency did not trace frequency changes correctly when
the userspace governor was used or when CPU cores' frequency depend
on each other.
-> Moving this into the CPUFREQ_POSTCHANGE notifier and pass the cpu
which gets switched automatically fixes this.Robert Schoene provided some important fixes on top of my initial
quick shot version which are integrated in this patch:
- Forgot some changes in power_end trace (TP_printk/variable names)
- Variable dummy in power_end must now be cpu_id
- Use static 64 bit variable instead of unsigned int for cpu_idSigned-off-by: Thomas Renninger
CC: davej@redhat.com
CC: arjan@infradead.org
CC: linux-kernel@vger.kernel.org
CC: robert.schoene@tu-dresden.de
Tested-by: robert.schoene@tu-dresden.de
Signed-off-by: Dave Jones -
lock_policy_rwsem_* and unlock_policy_rwsem_* functions are scheduled
to be unexported when 2.6.33. Now there are no other callers of them
out of cpufreq.c, unexport them and make them static.Signed-off-by: WANG Cong
Cc: Venkatesh Pallipadi
Signed-off-by: Dave Jones -
We didn't free policy->related_cpus in error path err_unlock_policy.
This is catched by following kmemleak report:unreferenced object 0xffff88022a0b96d0 (size 512):
comm "modprobe", pid 886, jiffies 4294689177 (age 780.694s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[] create_object+0x186/0x281
[] kmemleak_alloc+0x60/0xa7
[] kmem_cache_alloc_node_notrace+0x120/0x142
[] alloc_cpumask_var_node+0x2c/0xd7
[] alloc_cpumask_var+0x11/0x13
[] zalloc_cpumask_var+0xf/0x11
[] cpufreq_add_dev+0x11f/0x547
[] sysdev_driver_register+0xc2/0x11d
[] cpufreq_register_driver+0xcb/0x1b8
[] 0xffffffffa032e040
[] do_one_initcall+0x5e/0x15c
[] sys_init_module+0xa6/0x1e6
[] system_call_fastpath+0x16/0x1b
[] 0xffffffffffffffffSigned-off-by: Xiaotian Feng
Cc: Thomas Renninger
Cc: Prarit Bhargava
Signed-off-by: Dave Jones -
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
09 May, 2010
1 commit
10 Apr, 2010
1 commit
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Multiple modules used to define those which are with identical
functionality and were needlessly replicated among the different cpufreq
drivers. Push them into the header and remove duplication.Signed-off-by: Borislav Petkov
LKML-Reference:
Reviewed-by: Thomas Renninger
Signed-off-by: H. Peter Anvin
01 Apr, 2010
1 commit
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There is no need to do sysfs_remove_link() or kobject_put() etc.
when policy_rwsem_write is held, move them after releasing the lock.This fixes the lockdep warning:
halt/4071 is trying to acquire lock:
(s_active){++++.+}, at: [] .sysfs_addrm_finish+0x58/0xc0but task is already holding lock:
(&per_cpu(cpu_policy_rwsem, cpu)){+.+.+.}, at: [] .lock_policy_rwsem_write+0x84/0xf4Reported-by: Benjamin Herrenschmidt
Signed-off-by: WANG Cong
Cc: Johannes Berg
Cc: Venkatesh Pallipadi
Signed-off-by: Dave Jones
08 Mar, 2010
1 commit
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Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime* potentially better optimized code as the compiler
can assume that the const data cannot be changed* the compiler/linker move const data into .rodata
and therefore exclude them from false sharingSigned-off-by: Emese Revfy
Acked-by: David Teigland
Acked-by: Matt Domsch
Acked-by: Maciej Sosnowski
Acked-by: Hans J. Koch
Acked-by: Pekka Enberg
Acked-by: Jens Axboe
Acked-by: Stephen Hemminger
Signed-off-by: Greg Kroah-Hartman
15 Dec, 2009
1 commit
-
* '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
25 Nov, 2009
2 commits
-
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) limitiationsTherefore 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-cpufreqTested 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 limitationCC: Pallipadi Venkatesh
CC: Len Brown
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.netSigned-off-by: Thomas Renninger
Signed-off-by: Dave Jones -
No need to export these symbols; make them static.
cpufreq_add_dev_policy
cpufreq_add_dev_symlink
cpufreq_add_dev_interfaceSigned-off-by: Alex Chiang
Signed-off-by: Dave Jones
18 Nov, 2009
2 commits
-
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 devicesSigned-off-by: Prarit Bhargava
Signed-off-by: Dave Jones -
Currently on governer backup/restore path we storing governor's pointer.
This is wrong because one may unload governor's module after cpu goes
offline. As result use-after-free will take place on restored cpu.
It is not easy to exploit this bug, but still we have to close this
issue ASAP. Issue was introduced by following commit
084f34939424161669467c19280dbcf637730314##TESTCASE##
#!/bin/sh -x
modprobe acpi_cpufreq
# Any non default governor, in may case it is "ondemand"
modprobe cpufreq_ondemand
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
rmmod acpi_cpufreq
rmmod cpufreq_ondemand
modprobe acpi_cpufreq # << use-after-free here.Signed-off-by: Dmitry Monakhov
Signed-off-by: Dave Jones
29 Oct, 2009
1 commit
-
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
Cc: Rusty Russell
02 Sep, 2009
9 commits
-
remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)
commit 42a06f2166f2f6f7bf04f32b4e823eacdceafdc9
Missed a call site for CPUFREQ_GOV_STOP to remove the rwlock taken around the
teardown. To make a long story short, the rwlock write-lock causes a circular
dependency with cancel_delayed_work_sync(), because the timer handler takes the
read lock.Note that all callers to __cpufreq_set_policy are taking the rwsem. All sysfs
callers (writers) hold the write rwsem at the earliest sysfs calling stage.However, the rwlock write-lock is not needed upon governor stop.
Signed-off-by: Mathieu Desnoyers
Acked-by: Venkatesh Pallipadi
CC: rjw@sisk.pl
CC: mingo@elte.hu
CC: Shaohua Li
CC: Pekka Enberg
CC: Dave Young
CC: "Rafael J. Wysocki"
CC: Rusty Russell
CC: trenn@suse.de
CC: sven.wegener@stealer.net
CC: cpufreq@vger.kernel.org
Signed-off-by: Dave Jones -
Currently everything in the cpufreq layer is per core based.
This does not reflect reality, for example ondemand on conservative
governors have global sysfs variables.Introduce a global cpufreq directory and add the kobject to the governor
struct, so that governors can easily access it.
The directory is initialized in the cpufreq_core_init initcall and thus will
always be created if cpufreq is compiled in, even if no cpufreq driver is
active later.Signed-off-by: Thomas Renninger
Signed-off-by: Dave Jones -
Doing:
echo 0 >cpu1/online
echo 1 >cpu1/onlineon a managed CPU will result in:
Jul 22 15:15:37 linux kernel: [ 80.013864] WARNING: at fs/sysfs/dir.c:487 sysfs_add_one+0xcf/0xe6()
Jul 22 15:15:37 linux kernel: [ 80.013866] Hardware name: To Be Filled By O.E.M.
Jul 22 15:15:37 linux kernel: [ 80.013868] sysfs: cannot create duplicate filename '/devices/system/cpu/cpu1/cpufreq'
Jul 22 15:15:37 linux kernel: [ 80.013870] Modules linked in: powernow_k8
Jul 22 15:15:37 linux kernel: [ 80.013874] Pid: 5750, comm: bash Not tainted 2.6.31-rc2 #40
Jul 22 15:15:37 linux kernel: [ 80.013876] Call Trace:
Jul 22 15:15:37 linux kernel: [ 80.013879] [] ? sysfs_add_one+0xcf/0xe6
Jul 22 15:15:37 linux kernel: [ 80.013884] [] warn_slowpath_common+0x77/0xa4
Jul 22 15:15:37 linux kernel: [ 80.013888] [] warn_slowpath_fmt+0x3c/0x3e
Jul 22 15:15:37 linux kernel: [ 80.013891] [] sysfs_add_one+0xcf/0xe6
Jul 22 15:15:37 linux kernel: [ 80.013894] [] create_dir+0x58/0x87
Jul 22 15:15:37 linux kernel: [ 80.013898] [] sysfs_create_dir+0x38/0x4f
Jul 22 15:15:37 linux kernel: [ 80.013902] [] kobject_add_internal+0x11f/0x1de
Jul 22 15:15:37 linux kernel: [ 80.013905] [] kobject_add_varg+0x41/0x4e
Jul 22 15:15:37 linux kernel: [ 80.013908] [] kobject_init_and_add+0x4c/0x57
Jul 22 15:15:37 linux kernel: [ 80.013913] [] ? mark_lock+0x22/0x228
Jul 22 15:15:37 linux kernel: [ 80.013918] [] cpufreq_add_dev_interface+0x40/0x1e4
...This bug slipped in by git commit:
150b06f7f223cfd0f808737a5243cceca8ea47faWhen splitting up cpufreq_add_dev, the whole cpufreq_add_dev function
is not left anymore, only cpufreq_add_dev_policy.
This patch should reconstruct the identical functionality again as it
was before the split.CC: Venkatesh Pallipadi
Signed-off-by: Thomas Renninger
Signed-off-by: Dave Jones -
Signed-off-by: Dave Jones
-
Signed-off-by: Dave Jones
-
Signed-off-by: Dave Jones
-
Signed-off-by: Dave Jones
-
Signed-off-by: Dave Jones
-
Commit 4bc5d3413503 is broken and causes regressions:
(1) cpufreq_driver->resume() and ->suspend() were only called on
__powerpc__, but you could set them on all architectures. In fact,
->resume() was defined and used before the PPC-related commit
42d4dc3f4e1e complained about in 4bc5d3413503.(2) Therfore, the resume functions in acpi_cpufreq and speedstep-smi
would never be called.(3) This means speedstep-smi would be unusuable after suspend or resume.
The _real_ problem was calling cpufreq_driver->get() with interrupts
off, but it re-enabling interrupts on some platforms. Why is ->get()
necessary?Some systems like to change the CPU frequency behind our
back, especially during BIOS-intensive operations like suspend or
resume. If such systems also use a CPU frequency-dependant timing loop,
delays might be off by large factors. Therefore, we need to ascertain
as soon as possible that the CPU frequency is indeed at the speed we
think it is. You can do this two ways: either setting it anew, or trying
to get it. The latter is what was done, the former also has the same IRQ
issue.So, let's try something different: defer the checking to after interrupts
are re-enabled, by calling cpufreq_update_policy() (via schedule_work()).
Timings may be off until this later stage, so let's watch out for
resume regressions caused by the deferred handling of frequency changes
behind the kernel's back.Signed-off-by: Dominik Brodowski
Signed-off-by: Dave Jones
05 Aug, 2009
3 commits
-
The suspend code runs with interrupts disabled, and the powerpc workaround we
do in the cpufreq suspend hook calls the drivers ->get method.powernow-k8's ->get does an smp_call_function_single
which needs interrupts enabledcpufreq's suspend/resume code was added in 42d4dc3f4e1e to work around
a hardware problem on ppc powerbooks. If we make all this code
conditional on powerpc, we avoid the issue above.Signed-off-by: Dave Jones
-
The first offline/online cycle is successful, the second not.
Doing:
echo 0 >cpu1/online
echo 1 >cpu1/online
echo 0 >cpu1/onlineThe last command will trigger:
Jul 22 14:39:50 linux kernel: [ 593.210125] ------------[ cut here ]------------
Jul 22 14:39:50 linux kernel: [ 593.210139] WARNING: at lib/kref.c:43 kref_get+0x23/0x2b()
Jul 22 14:39:50 linux kernel: [ 593.210144] Hardware name: To Be Filled By O.E.M.
Jul 22 14:39:50 linux kernel: [ 593.210148] Modules linked in: powernow_k8
Jul 22 14:39:50 linux kernel: [ 593.210158] Pid: 378, comm: kondemand/2 Tainted: G W 2.6.31-rc2 #38
Jul 22 14:39:50 linux kernel: [ 593.210163] Call Trace:
Jul 22 14:39:50 linux kernel: [ 593.210171] [] ? kref_get+0x23/0x2b
Jul 22 14:39:50 linux kernel: [ 593.210181] [] warn_slowpath_common+0x77/0xa4
Jul 22 14:39:50 linux kernel: [ 593.210190] [] warn_slowpath_null+0xf/0x11
Jul 22 14:39:50 linux kernel: [ 593.210198] [] kref_get+0x23/0x2b
Jul 22 14:39:50 linux kernel: [ 593.210206] [] kobject_get+0x1a/0x22
Jul 22 14:39:50 linux kernel: [ 593.210214] [] cpufreq_cpu_get+0x8a/0xcb
Jul 22 14:39:50 linux kernel: [ 593.210222] [] __cpufreq_driver_getavg+0x1d/0x67
Jul 22 14:39:50 linux kernel: [ 593.210231] [] do_dbs_timer+0x158/0x27f
Jul 22 14:39:50 linux kernel: [ 593.210240] [] worker_thread+0x200/0x313
...The output continues on every do_dbs_timer ondemand freq checking poll.
This regression was introduced by git commit:
3f4a782b5ce2698b1870b5a7b573cd721d4fce33The policy is released when the cpufreq device is removed in:
__cpufreq_remove_dev():
/* if this isn't the CPU which is the parent of the kobj, we
* only need to unlink, put and exit
*/Not creating the symlink is not sever at all.
As long as:
sysfs_remove_link(&sys_dev->kobj, "cpufreq");
handles it gracefully that the symlink did not exist.
Possibly no error should be returned at all, because ondemand
governor would still provide the same functionality.
Userspace in userspace gov case might be confused if the link
is missing.Resolves http://bugzilla.kernel.org/show_bug.cgi?id=13903
CC: Mathieu Desnoyers
CC: Venkatesh Pallipadi
Signed-off-by: Thomas Renninger
Signed-off-by: Dave Jones -
Suspend/Resume fails on multi socket, multi core systems because the cpufreq
code erroneously sets the per_cpu policy_cpu value when a logical cpu is
offline.This most notably results in missing sysfs files that are used to set the
cpu frequencies of the various cpus.Signed-off-by: Prarit Bhargava
Signed-off-by: Dave Jones