29 Jan, 2007
1 commit
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Trivial patch to check sysfs_create_link return values.
Fail gracefully if needed.Signed-off-by: Ahmed Darwish
Signed-off-by: Dave Jones
23 Dec, 2006
1 commit
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Fixes the oops in cpufreq_stats with acpi_cpufreq driver. The issue was
that the frequency was reported as 0 in acpi-cpufreq.c. The bug is due to
different indicies for freq_table and ACPI perf table.Also adds a check in cpufreq_stats to check for error return from
freq_table_get_index() and avoid using the error return value.Patch fixes the issue reported at
http://www.ussg.iu.edu/hypermail/linux/kernel/0611.2/0629.html
and also other similar issue here
http://bugme.osdl.org/show_bug.cgi?id=7383 comment 53Signed-off-by: Dhaval Giani
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Andrew Morton
Signed-off-by: Dave Jones
13 Dec, 2006
2 commits
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This patch fixes a typo in cpufreq.c
From: Dhaval Giani
Signed-off-by: Dave Jones -
Conflicts:
drivers/cpufreq/cpufreq.c
08 Dec, 2006
1 commit
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There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn,
prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus
generating compiler warnings of unused symbols, hence forcing people to add
#ifdefs.the compiler can skip truly unused functions just fine:
text data bss dec hex filename
1624412 728710 3674856 6027978 5bfaca vmlinux.before
1624412 728710 3674856 6027978 5bfaca vmlinux.after[akpm@osdl.org: topology.c fix]
Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Nov, 2006
3 commits
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Fix up for make allyesconfig.
Signed-Off-By: David Howells
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Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.To make this work, an extra flag is introduced into the management side of the
work_struct. This governs auto-release of the structure upon execution.Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function. This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated.. This is a
problem if the auxiliary data is taken away (as done by the last patch).However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems. But then the work function must itself release the
work_struct by calling work_release().In most cases, automatic release is fine, so this is the default. Special
initiators exist for the non-auto-release case (ending in _NAR).Signed-Off-By: David Howells
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The ONDEMAND governor needs FREQ_TABLE
Signed-off-by: Mattia Dongili
Signed-off-by: Dave Jones
Signed-off-by: Linus Torvalds
21 Nov, 2006
1 commit
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This is a quick hack to overcome the fact that SRCU currently does not
allow static initializers, and we need to sometimes initialize those
things before any other initializers (even "core" ones) can do so.Currently we don't allow this at all for modules, and the only user that
needs is right now is cpufreq. As reported by Thomas Gleixner:"Commit b4dfdbb3c707474a2254c5b4d7e62be31a4b7da9 ("[PATCH] cpufreq:
make the transition_notifier chain use SRCU breaks cpu frequency
notification users, which register the callback > on core_init
level."Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Arjan van de Ven
Cc: Andrew Morton ,
Signed-off-by: Linus Torvalds
07 Nov, 2006
1 commit
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Clean up cpufreq subsystem to fix coding style issues and to improve
the readability.Signed-off-by: Gautham R Shenoy
Signed-off-by: Dave Jones
21 Oct, 2006
1 commit
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Signed-off-by: Jeff Garzik
Signed-off-by: Andrew Morton
Signed-off-by: Dave Jones
16 Oct, 2006
1 commit
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Enable ondemand governor and acpi-cpufreq to use IA32_APERF and IA32_MPERF MSR
to get active frequency feedback for the last sampling interval. This will
make ondemand take right frequency decisions when hardware coordination of
frequency is going on.Without APERF/MPERF, ondemand can take wrong decision at times due
to underlying hardware coordination or TM2.
Example:
* CPU 0 and CPU 1 are hardware cooridnated.
* CPU 1 running at highest frequency.
* CPU 0 was running at highest freq. Now ondemand reduces it to
some intermediate frequency based on utilization.
* Due to underlying hardware coordination with other CPU 1, CPU 0 continues to
run at highest frequency (as long as other CPU is at highest).
* When ondemand samples CPU 0 again next time, without actual frequency
feedback from APERF/MPERF, it will think that previous frequency change
was successful and can go to wrong target frequency. This is because it
thinks that utilization it has got this sampling interval is when running at
intermediate frequency, rather than actual highest frequency.More information about IA32_APERF IA32_MPERF MSR:
Refer to IA-32 Intel® Architecture Software Developer's Manual at
http://developer.intel.comSigned-off-by: Venkatesh Pallipadi
Signed-off-by: Dave Jones
04 Oct, 2006
1 commit
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This patch (as762) changes the cpufreq_transition_notifier_list from a
blocking_notifier_head to an srcu_notifier_head. This will prevent errors
caused attempting to call down_read() to access the notifier chain at a
time when interrupts must remain disabled, during system suspend.It's not clear to me whether this is really necessary; perhaps the chain
could be made into an atomic_notifier. However a couple of the callout
routines do use blocking operations, so this approach seems safer.The head of the notifier chain needs to be initialized before use; this is
done by an __init routine at core_initcall time. If this turns out not to
be a good choice, it can easily be changed.Signed-off-by: Alan Stern
Cc: "Paul E. McKenney"
Cc: Jesse Brandeburg
Cc: Dave Jones
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Sep, 2006
1 commit
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Signed-off-by: Dave Jones
23 Sep, 2006
1 commit
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Lukewarm IQ detected in hotplug locking
BUG: warning at kernel/cpu.c:38/lock_cpu_hotplug()
[] lock_cpu_hotplug+0x42/0x65
[] cpufreq_update_policy+0x25/0xad
[] kprobe_flush_task+0x18/0x40
[] schedule+0x63f/0x68b
[] __link_module+0x0/0x1f
[] __cond_resched+0x16/0x34
[] cond_resched+0x26/0x31
[] wait_for_completion+0x17/0xb1
[] cpufreq_stat_cpu_callback+0x13/0x20 [cpufreq_stats]
[] cpufreq_stats_init+0x74/0x8b [cpufreq_stats]
[] sys_init_module+0x91/0x174
[] sysenter_past_esp+0x56/0x79As there are other places that call cpufreq_update_policy without
the hotplug lock, it seems better to keep the hotplug locking
at the lower level for the time being until this is revamped.Signed-off-by: Dave Jones
06 Sep, 2006
1 commit
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drivers/cpufreq/cpufreq_ondemand.c:323:2: warning: Using plain integer as NULL pointer
Signed-off-by: Dave Jones
14 Aug, 2006
1 commit
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This patch makes the needlessly global powersave_bias_target() static.
Signed-off-by: Adrian Bunk
Signed-off-by: Dave Jones
12 Aug, 2006
3 commits
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ondemand selects the minimum frequency that can retire
a workload with negligible idle time -- ideally resulting in the highest
performance/power efficiency with negligible performance impact.But on some systems and some workloads, this algorithm
is more performance biased than necessary, and
de-tuning it a bit to allow some performance impact
can save measurable power.This patch adds a "powersave_bias" tunable to ondemand
to allow it to reduce its target frequency by a specified percent.By default, the powersave_bias is 0 and has no effect.
powersave_bias is in units of 0.1%, so it has an effective range
of 1 through 1000, resulting in 0.1% to 100% impact.In practice, users will not be able to detect a difference between
0.1% increments, but 1.0% increments turned out to be too large.
Also, the max value of 1000 (100%) would simply peg the system
in its deepest power saving P-state, unless the processor really has
a hardware P-state at 0Hz:-)For example, If ondemand requests 2.0GHz based on utilization,
and powersave_bias=100, this code will knock 10% off the target
and seek a target of 1.8GHz instead of 2.0GHz until the
next sampling. If 1.8 is an exact match with an hardware frequency
we use it, otherwise we average our time between the frequency
next higher than 1.8 and next lower than 1.8.Note that a user or administrative program can change powersave_bias
at run-time depending on how they expect the system to be used.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Alexey Starikovskiy
Signed-off-by: Dave Jones -
Try to make dbs_check_cpu() call on all CPUs at the same jiffy.
This will help when multiple cores share P-states via Hardware Coordination.Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Alexey Starikovskiy
Signed-off-by: Dave Jones -
Signed-off-by: Dave Jones
01 Aug, 2006
3 commits
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Demand-load cpufreq governor modules if needed.
Signed-off-by: Jeremy Fitzhardinge
Signed-off-by: Dave Jones -
Adds a __find_governor() helper function to look up a governor by
name. Also restructures some error handling to conform to the
"single-exit" model which is generally preferred for kernel code.Signed-off-by: Jeremy Fitzhardinge
Signed-off-by: Dave Jones -
I just stumbled on this bug/feature, this is how to reproduce it:
# echo 450000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
# echo 450000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
# echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# cpufreq-info -p
450000 450000 powersave
# echo 1800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq ; echo $?
0
# cpufreq-info -p
450000 450000 powersaveHere it is. The kernel refuses to set a min_freq higher than the
max_freq but it allows a max_freq lower than min_freq (lowering min_freq
also).This behaviour is pretty straightforward (but undocumented) and it
doesn't return an error altough failing to accomplish the requested
action (set min_freq).
The problem (IMO) is basically that userspace is not allowed to set a
full policy atomically while the kernel always does that thus it must
enforce an ordering on operations.The attached patch returns -EINVAL if trying to increase frequencies
starting from scaling_min_freq and documents the correct ordering of writes.Signed-off-by: Mattia Dongili
Signed-off-by: Dominik Brodowski
Signed-off-by: Dave Jones--
26 Jul, 2006
1 commit
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The patch below moves the cpu hotplugging higher up in the cpufreq
layering; this is needed to avoid recursive taking of the cpu hotplug
lock and to otherwise detangle the mess.The new rules are:
1. you must do lock_cpu_hotplug() around the following functions:
__cpufreq_driver_target
__cpufreq_governor (for CPUFREQ_GOV_LIMITS operation only)
__cpufreq_set_policy
2. governer methods (.governer) must NOT take the lock_cpu_hotplug()
lock in any way; they are called with the lock taken already
3. if your governer spawns a thread that does things, like calling
__cpufreq_driver_target, your thread must honor rule #1.
4. the policy lock and other cpufreq internal locks nest within
the lock_cpu_hotplug() lock.I'm not entirely happy about how the __cpufreq_governor rule ended up
(conditional locking rule depending on the argument) but basically all
callers pass this as a constant so it's not too horrible.The patch also removes the cpufreq_governor() function since during the
locking audit it turned out to be entirely unused (so no need to fix it)The patch works on my testbox, but it could use more testing
(otoh... it can't be much worse than the current code)Signed-off-by: Arjan van de Ven
Signed-off-by: Linus Torvalds
24 Jul, 2006
1 commit
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Shutting down the ondemand policy was fraught with potential
problems, causing issues for SMP suspend (which wants to hot-
unplug) all but the last CPU.This should fix at least the worst problems (divide-by-zero
and infinite wait for the workqueue to shut down).Signed-off-by: Linus Torvalds
08 Jul, 2006
1 commit
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[ There's some not quite baked bits in cpufreq-git right now
so sending this on as a patch instead ]On Thu, 2006-07-06 at 07:58 -0700, Tom London wrote:
> After installing .2356 I get this each time I boot:
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> -------------------------------------------------------
> S06cpuspeed/1620 is trying to acquire lock:
> (dbs_mutex){--..}, at: [] mutex_lock+0x21/0x24
>
> but task is already holding lock:
> (cpucontrol){--..}, at: [] mutex_lock+0x21/0x24
>
> which lock already depends on the new lock.
>make sure the cpu hotplug recursive mutex (yuck) is taken early in the
cpufreq codepaths to avoid a AB-BA deadlock.Signed-off-by: Arjan van de Ven
Signed-off-by: Dave Jones
Signed-off-by: Linus Torvalds
05 Jul, 2006
1 commit
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* master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq:
Move workqueue exports to where the functions are defined.
[CPUFREQ] Misc cleanups in ondemand.
[CPUFREQ] Make ondemand sampling per CPU and remove the mutex usage in sampling path.
[CPUFREQ] Add queue_delayed_work_on() interface for workqueues.
[CPUFREQ] Remove slowdown from ondemand sampling path.
01 Jul, 2006
1 commit
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Signed-off-by: Jörn Engel
Signed-off-by: Adrian Bunk
30 Jun, 2006
3 commits
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Misc cleanups in ondemand. Should have zero functional impact.
Also adding Alexey as author.Signed-off-by: Alexey Starikovskiy
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Dave Jones -
Make ondemand sampling per CPU and remove the mutex usage in sampling path.
Signed-off-by: Alexey Starikovskiy
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Dave Jones -
Remove slowdown from ondemand sampling path. This reduces the code path length
in dbs_check_cpu() by half. slowdown was not used by ondemand by default.
If there are any user level tools that were using this tunable, they
may report error now.Signed-off-by: Alexey Starikovskiy
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Dave Jones
28 Jun, 2006
3 commits
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Make notifier_blocks associated with cpu_notifier as __cpuinitdata.
__cpuinitdata makes sure that the data is init time only unless
CONFIG_HOTPLUG_CPU is defined.Signed-off-by: Chandra Seetharaman
Cc: Ashok Raj
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
CPUs come online only at init time (unless CONFIG_HOTPLUG_CPU is defined).
So, cpu_notifier functionality need to be available only at init time.This patch makes register_cpu_notifier() available only at init time, unless
CONFIG_HOTPLUG_CPU is defined.This patch exports register_cpu_notifier() and unregister_cpu_notifier() only
if CONFIG_HOTPLUG_CPU is defined.Signed-off-by: Chandra Seetharaman
Cc: Ashok Raj
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In 2.6.17, there was a problem with cpu_notifiers and XFS. I provided a
band-aid solution to solve that problem. In the process, i undid all the
changes you both were making to ensure that these notifiers were available
only at init time (unless CONFIG_HOTPLUG_CPU is defined).We deferred the real fix to 2.6.18. Here is a set of patches that fixes the
XFS problem cleanly and makes the cpu notifiers available only at init time
(unless CONFIG_HOTPLUG_CPU is defined).If CONFIG_HOTPLUG_CPU is defined then cpu notifiers are available at run
time.This patch reverts the notifier_call changes made in 2.6.17
Signed-off-by: Chandra Seetharaman
Cc: Ashok Raj
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Jun, 2006
1 commit
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drivers/cpufreq/cpufreq_ondemand.c: In function 'do_dbs_timer':
drivers/cpufreq/cpufreq_ondemand.c:374: warning: implicit declaration of function 'lock_cpu_hotplug'
drivers/cpufreq/cpufreq_ondemand.c:381: warning: implicit declaration of function 'unlock_cpu_hotplug'
drivers/cpufreq/cpufreq_conservative.c: In function 'do_dbs_timer':
drivers/cpufreq/cpufreq_conservative.c:425: warning: implicit declaration of function 'lock_cpu_hotplug'
drivers/cpufreq/cpufreq_conservative.c:432: warning: implicit declaration of function 'unlock_cpu_hotplug'Cc: Dave Jones
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Jun, 2006
1 commit
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Rootcaused the bug to a deadlock in cpufreq and ondemand. Due to non-existent
ordering between cpu_hotplug lock and dbs_mutex. Basically a race condition
between cpu_down() and do_dbs_timer().cpu_down() flow:
* cpu_down() call for CPU 1
* Takes hot plug lock
* Calls pre down notifier
* cpufreq notifier handler calls cpufreq_driver_target() which takes
cpu_hotplug lock again. OK as cpu_hotplug lock is recursive in same
process context
* CPU 1 goes down
* Calls post down notifier
* cpufreq notifier handler calls ondemand event stop which takes dbs_mutexSo, cpu_hotplug lock is taken before dbs_mutex in this flow.
do_dbs_timer is triggerred by a periodic timer event.
It first takes dbs_mutex and then takes cpu_hotplug lock in
cpufreq_driver_target().
Note the reverse order here compared to above. So, if this timer event happens
at right moment during cpu_down, system will deadlok.Attached patch fixes the issue for both ondemand and conservative.
Signed-off-by: Venkatesh Pallipadi
Signed-off-by: Dave Jones
05 Jun, 2006
1 commit
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Remove KERN_* suffixes from some cpufreq driver's dprintk-s.
Signed-off-by: Jan Beulich
Signed-off-by: Dave Jones
31 May, 2006
3 commits
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Signed-off-by: Dave Jones
-
Signed-off-by: Dave Jones
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Signed-off-by: Dave Jones