27 Mar, 2007
1 commit
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Ingo reported it on lkml in the thread
"2.6.21-rc5: maxcpus=1 crash in cpufreq: kernel BUG at drivers/cpufreq/cpufreq.c:82!"This check added to remove_dev is symmetric to one in add_dev and handles
callbacks for offline cpus cleanly.Signed-off-by: Venkatesh Pallipadi
Acked-by: Ingo Molnar
Signed-off-by: Linus Torvalds
27 Feb, 2007
2 commits
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This reverts commit aeeddc1435c37fa3fc844f31d39c185b08de4158, which was
half-baked and broken. It just resulted in compile errors, since
cpufreq_register_driver() still changes the 'driver_data' by setting
bits in the flags field. So claiming it is 'const' _really_ doesn't
work.Signed-off-by: Linus Torvalds
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* master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ] constify some data tables.
[CPUFREQ] constify cpufreq_driver where possible.
{rd,wr}msr_on_cpu SMP=n optimization
[CPUFREQ] cpufreq_ondemand.c: don't use _WORK_NAR
rdmsr_on_cpu, wrmsr_on_cpu
[CPUFREQ] Revert default on deprecated config X86_SPEEDSTEP_CENTRINO_ACPI
23 Feb, 2007
1 commit
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Not all cases are possible due to ->flags being set at runtime
on some drivers.Signed-off-by: Dave Jones
21 Feb, 2007
1 commit
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Looks like dbs_timer() is very careful wrt per_cpu(cpu_dbs_info),
and it doesn't need the help of WORK_STRUCT_NOAUTOREL.Signed-off-by: Oleg Nesterov
Acked-By: David Howells
Signed-off-by: Dave Jones
17 Feb, 2007
1 commit
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* master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ] Longhaul - Redo Longhaul ver. 2
[CPUFREQ] EPS - Correct 2nd brand test
[CPUFREQ] Longhaul - Separate frequency and voltage transition
[CPUFREQ] Longhaul - Models of Nehemiah
[CPUFREQ] Whitespace fixup
[CPUFREQ] Longhaul - Simplier minmult
[CPUFREQ] CPU_FREQ_TABLE shouldn't be a def_tristate
[CPUFREQ] ondemand governor use new cpufreq rwsem locking in work callback
[CPUFREQ] ondemand governor restructure the work callback
[CPUFREQ] Rewrite lock in cpufreq to eliminate cpufreq/hotplug related issues
[CPUFREQ] Remove hotplug cpu crap
[CPUFREQ] Enhanced PowerSaver driver
[CPUFREQ] Longhaul - Add VT8235 support
[CPUFREQ] Longhaul - Fix guess_fsb function
[CPUFREQ] Longhaul - Remove duplicate tables
[CPUFREQ] Longhaul - Introduce Nehemiah C
[CPUFREQ] fix cpuinfo_cur_freq for CPU_HW_PSTATE
[CPUFREQ] Longhaul - Remove "ignore_latency" option
15 Feb, 2007
1 commit
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After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).Signed-off-by: Tim Schmielau
Acked-by: Russell King
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Feb, 2007
6 commits
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Signed-off-by: Dave Jones
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CPU_FREQ_TABLE enables helper code and gets select'ed when it's required.
Building it as a module when it's not required doesn't seem to make much sense.
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Dave Jones -
Eliminate flush_workqueue in cpufreq_governor(STOP) callpath. Using flush
there has a deadlock potential as inhttp://uwsg.iu.edu/hypermail/linux/kernel/0611.3/1223.html
Also, cleanup the locking issues with do_dbs_timer delayed_work callback. As
it changes the CPU frequency using __cpufreq_target, it needs to have
policy_rwsem in write mode, which also protects it from hot plug.Signed-off-by: Venkatesh Pallipadi
Cc: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Dave Jones -
Restructure the delayed_work callback in ondemand.
This eliminates the need for smp_processor_id in the callback function and
also helps in proper locking and avoiding flush_workqueue when stopping the
governor (done in subsequent patch).Signed-off-by: Venkatesh Pallipadi
Cc: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Dave Jones -
Yet another attempt to resolve cpufreq and hotplug locking issues.
Patchset has 3 patches:
* Rewrite the lock infrastructure of cpufreq using a per cpu rwsem.
* Minor restructuring of work callback in ondemand driver.
* Use the new cpufreq rwsem infrastructure in ondemand work.This patch:
Convert policy->lock to rwsem and move it to per_cpu area.
This rwsem will protect against both changing/accessing policy
related parameters and CPU hot plug/unplug.[malattia@linux.it: fix oops in kref_put()]
Cc: Gautham R Shenoy
Signed-off-by: Venkatesh Pallipadi
Cc: Gautham R Shenoy
Signed-off-by: Mattia Dongili
Signed-off-by: Andrew Morton
Signed-off-by: Dave Jones -
The hotplug CPU locking in cpufreq is horrendous. No-one seems to care
enough to fix it, so just remove it so that the 99.9% of the real world
users of this code can use cpufreq without being bothered by warnings.Signed-off-by: Andrew Morton
Signed-off-by: Dave Jones
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.
