Commit graph

85 commits

Author SHA1 Message Date
Jeremy Fitzhardinge
ea71497020 [CPUFREQ] [2/2] demand load governor modules.
Demand-load cpufreq governor modules if needed.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-07-31 18:37:06 -04:00
Jeremy Fitzhardinge
3bcb09a356 [CPUFREQ] [1/2] add __find_governor helper and clean up some error handling.
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 <jeremy@goop.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-07-31 18:37:06 -04:00
Mattia Dongili
9c9a43ed27 [CPUFREQ] return error when failing to set minfreq
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 powersave

Here 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 <malattia@linux.it>
Signed-off-by: Dominik Brodowski <linux at dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>

--
2006-07-31 18:37:05 -04:00
Arjan van de Ven
153d7f3fca [PATCH] Reorganize the cpufreq cpu hotplug locking to not be totally bizare
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 <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-26 07:21:40 -07:00
Linus Torvalds
2cd7cbdf4b [cpufreq] ondemand: make shutdown sequence more robust
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 <torvalds@osdl.org>
2006-07-23 12:05:00 -07:00
Dave Jones
a496e25dfb [PATCH] Fix cpufreq vs hotplug lockdep recursion.
[ 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: [<c060d6bb>] mutex_lock+0x21/0x24
>
> but task is already holding lock:
>  (cpucontrol){--..}, at: [<c060d6bb>] 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 <arjan@linux.intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-07 09:46:45 -07:00
Linus Torvalds
ca78f6baca Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
* 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.
2006-07-04 14:00:26 -07:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Venkatesh Pallipadi
ffac80e925 [CPUFREQ] Misc cleanups in ondemand.
Misc cleanups in ondemand. Should have zero functional impact.
Also adding Alexey as author.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-06-30 01:36:40 -04:00
Venkatesh Pallipadi
2f8a835c70 [CPUFREQ] Make ondemand sampling per CPU and remove the mutex usage in sampling path.
Make ondemand sampling per CPU and remove the mutex usage in sampling path.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-06-30 01:33:31 -04:00
Venkatesh Pallipadi
ccb2fe209d [CPUFREQ] Remove slowdown from ondemand sampling path.
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 <alexey.y.starikovskiy@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-06-30 01:29:47 -04:00
Chandra Seetharaman
74b85f3790 [PATCH] cpu hotplug: make cpu_notifier related notifier blocks __cpuinit only
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 <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:41 -07:00
Chandra Seetharaman
65edc68c34 [PATCH] cpu hotplug: make [un]register_cpu_notifier init time only
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 <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:41 -07:00
Chandra Seetharaman
9c7b216d23 [PATCH] cpu hotplug: revert init patch submitted for 2.6.17
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 <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:40 -07:00
Andrew Morton
138a0128c0 [PATCH] cpufreq build fix
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 <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 08:47:27 -07:00
Venkatesh Pallipadi
4ec223d02f [CPUFREQ] Fix ondemand vs suspend deadlock
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_mutex

So, 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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-06-21 18:30:26 -04:00
Jan Beulich
b10eec2246 [CPUFREQ] cpufreq core {d,}printk adjustments
Remove KERN_* suffixes from some cpufreq driver's dprintk-s.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-06-04 19:47:38 -04:00
Dave Jones
484944a5b0 [CPUFREQ] Remove more freq_table reinitialisations.
Signed-off-by: Dave Jones <davej@redhat.com>
2006-05-30 18:09:31 -04:00
Dave Jones
5557976ca9 [CPUFREQ] Fix another redundant initialisation in freq_table
Signed-off-by: Dave Jones <davej@redhat.com>
2006-05-30 17:59:48 -04:00
Dave Jones
355eb31801 [CPUFREQ] Remove duplicate assignment in freq_table
Signed-off-by: Dave Jones <davej@redhat.com>
2006-05-30 17:58:41 -04:00
Dave Jones
511e9ee170 [CPUFREQ] CodingStyle nits in cpufreq_stats.c
Signed-off-by: Dave Jones <davej@redhat.com>
2006-05-30 17:57:14 -04:00
Andi Kleen
6810b548b2 [PATCH] x86_64: Move ondemand timer into own work queue
Taking the cpu hotplug semaphore in a normal events workqueue
is unsafe because other tasks can wait for any workqueues with
it hold. This results in a deadlock.

Move the DBS timer into its own work queue which is not
affected by other work queue flushes to avoid this.

Has been acked by Venkatesh.

Cc: venkatesh.pallipadi@intel.com
Cc: cpufreq@lists.linux.org.uk
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-08 09:34:56 -07:00
Chandra Seetharaman
83d722f7e1 [PATCH] Remove __devinit and __cpuinit from notifier_call definitions
Few of the notifier_chain_register() callers use __init in the definition
of notifier_call.  It is incorrect as the function definition should be
available after the initializations (they do not unregister them during
initializations).

This patch fixes all such usages to _not_ have the notifier_call __init
section.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26 08:30:03 -07:00
Adrian Bunk
7b14dedd1f [CPUFREQ] drivers/cpufreq/cpufreq.c: static functions mustn't be exported
This patch removes the EXPORT_SYMBOL_GPL of the static function cpufreq_parse_governor().

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-04-18 17:24:52 -05:00
Thomas Renninger
7970e08bf0 [CPUFREQ] If max_freq got reduced (e.g. by _PPC) a write to sysfs scaling_governor let cpufreq core stuck at low max_freq for ever
The previous patch had bugs (locking and refcount).

This one could also be related to the latest DELL reports.
But they only slip into this if a user prog (e.g. powersave daemon does when
AC got (un) plugged due to a scheme change) echos something to
/sys/../cpufreq/scaling_governor
while the frequencies got limited by BIOS.

This one works:

Subject: Max freq stucks at low freq if reduced by _PPC and sysfs gov access

The problem is reproducable by(if machine is limiting freqs via BIOS):
 - Unplugging AC -> max freq gets limited
 - echo ${governor} >/sys/.../cpufreq/scaling_governor (policy->user_data.max
   gets overridden with policy->max and will never come up again.)

This patch exchanged the cpufreq_set_policy call to __cpufreq_set_policy and
duplicated it's functionality but did not override user_data.max.
The same happens with overridding min/max values. If freqs are limited and
you override the min freq value, the max freq global value will also get
stuck to the limited freq, even if BIOS allows all freqs again.
Last scenario does only happen if BIOS does not reduce the frequency
to the lowest value (should never happen, just for correctness...)

 drivers/cpufreq/cpufreq.c |   17 +++++++++++++++--
 1 files changed, 15 insertions(+), 2 deletions(-)

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-04-18 17:24:52 -05:00
Erik Mouw
4c41251e31 [CPUFREQ] Update LART site URL
Update LART site URL.

The LART website moved to http://www.lartmaker.nl/. This patch
updates the URL in CpuFreq specific files.

Signed-off-by: Erik Mouw <erik@bitwizard.nl>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-04-03 07:25:54 -05:00
Dave Jones
b82fbe6c42 [CPUFREQ] Remove pointless check in conservative governor.
< 0 checks on unsigned variables are pointless.

Signed-off-by: Dave Jones <davej@redhat.com>
2006-04-01 22:07:07 -05:00
Dave Jones
87c3227138 [CPUFREQ] trailing whitespace removal de-jour.
Signed-off-by: Dave Jones <davej@redhat.com>
2006-03-29 01:48:37 -05:00
Dave Jones
1f8b2c9d38 [CPUFREQ] extra debugging in cpufreq_add_dev()
Snipped from an otherwise rejected patch by Jan Beulich <jbeulich@novell.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-03-29 01:40:04 -05:00
Mattia Dongili
c326e27eb7 [CPUFREQ] cpufreq_conservative: keep ignore_nice_load and freq_step values when reselected
Keep the value of ignore_nice_load and freq_step of the conservative
governor after the governor is deselected and reselected.

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-03-28 12:20:18 -05:00
Dave Jones
0bb065f29b Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/cpufreq-2.6 2006-03-27 14:56:39 -05:00
Alan Stern
e041c68341 [PATCH] Notifier chain update: API changes
The kernel's implementation of notifier chains is unsafe.  There is no
protection against entries being added to or removed from a chain while the
chain is in use.  The issues were discussed in this thread:

    http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

We noticed that notifier chains in the kernel fall into two basic usage
classes:

	"Blocking" chains are always called from a process context
	and the callout routines are allowed to sleep;

	"Atomic" chains can be called from an atomic context and
	the callout routines are not allowed to sleep.

We decided to codify this distinction and make it part of the API.  Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name).  New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain.  The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.

With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed.  For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections.  (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)

There are some limitations, which should not be too hard to live with.  For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem.  Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain.  (This did happen in a couple of places and the code
had to be changed to avoid it.)

Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization.  Instead we use RCU.  The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.

Here is the list of chains that we adjusted and their classifications.  None
of them use the raw API, so for the moment it is only a placeholder.

  ATOMIC CHAINS
  -------------
arch/i386/kernel/traps.c:		i386die_chain
arch/ia64/kernel/traps.c:		ia64die_chain
arch/powerpc/kernel/traps.c:		powerpc_die_chain
arch/sparc64/kernel/traps.c:		sparc64die_chain
arch/x86_64/kernel/traps.c:		die_chain
drivers/char/ipmi/ipmi_si_intf.c:	xaction_notifier_list
kernel/panic.c:				panic_notifier_list
kernel/profile.c:			task_free_notifier
net/bluetooth/hci_core.c:		hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_expect_chain
net/ipv6/addrconf.c:			inet6addr_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_expect_chain
net/netlink/af_netlink.c:		netlink_chain

  BLOCKING CHAINS
  ---------------
arch/powerpc/platforms/pseries/reconfig.c:	pSeries_reconfig_chain
arch/s390/kernel/process.c:		idle_chain
arch/x86_64/kernel/process.c		idle_notifier
drivers/base/memory.c:			memory_chain
drivers/cpufreq/cpufreq.c		cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c		cpufreq_transition_notifier_list
drivers/macintosh/adb.c:		adb_client_list
drivers/macintosh/via-pmu.c		sleep_notifier_list
drivers/macintosh/via-pmu68k.c		sleep_notifier_list
drivers/macintosh/windfarm_core.c	wf_client_list
drivers/usb/core/notify.c		usb_notifier_list
drivers/video/fbmem.c			fb_notifier_list
kernel/cpu.c				cpu_chain
kernel/module.c				module_notify_list
kernel/profile.c			munmap_notifier
kernel/profile.c			task_exit_notifier
kernel/sys.c				reboot_notifier_list
net/core/dev.c				netdev_chain
net/decnet/dn_dev.c:			dnaddr_chain
net/ipv4/devinet.c:			inetaddr_chain

It's possible that some of these classifications are wrong.  If they are,
please let us know or submit a patch to fix them.  Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)

The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.

[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:44:50 -08:00
Dominik Brodowski
7c9d8c0e84 [PATCH] cpufreq_ondemand: add range check
Assert that cpufreq_target is, at least, called with the minimum frequency
allowed by this policy, not something lower. It triggered problems on ARM.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-26 11:11:03 +02:00
Eric Piel
9cbad61b41 [PATCH] cpufreq_ondemand: keep ignore_nice_load value when it is reselected
Keep the value of ignore_nice_load of the ondemand governor even after
the governor has been deselected and selected back. This is the behavior
of the other exported values of the ondemand governor and it's much more
user-friendly.

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-26 10:46:18 +02:00
Eric Piel
ff8c288d7d [PATCH] cpufreq_ondemand: Warn if it cannot run due to too long transition latency
Display a warning if the ondemand governor can not be selected due to a
transition latency of the cpufreq driver which is too long.

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-26 10:43:06 +02:00
Alexander Clouter
a159b82770 [PATCH] cpufreq_conservative: alternative initialise approach
Venki, author of cpufreq_ondemand, came up with a neater way to remove the
initialiser code from the main loop of my code and out to the point when the
governor is actually initialised.

Not only does it look but it also feels cleaner, plus its simpler to
understand.  It also saves a bunch of pointless conditional statements in the
main loop.

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-26 10:18:18 +02:00
Alexander Clouter
08a28e2e98 [PATCH] cpufreq_conservative: make for_each_cpu() safe
All these changes should make cpufreq_conservative safe in regards to the x86
for_each_cpu cpumask.h changes and whatnot.

Whilst making it safe a number of pointless for loops related to the cpu
mask's were removed.  I was never comfortable with all those for loops,
especially as the iteration is over the same data again and again for each
CPU you had in a single poll, an O(n^2) outcome to frequency scaling.

The approach I use is to assume by default no CPU's exist and it sets the
requested_freq to zero as a kind of flag, the reasoning is in the source ;)
If the CPU is queried and requested_freq is zero then it initialises the
variable to current_freq and then continues as if nothing happened which
should be the same net effect as before?

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-26 10:14:54 +02:00
Alexander Clouter
e8a0257225 [PATCH] cpufreq_conservative: alter default responsiveness
The sensible approach to making conservative less responsive than ondemand :)
As mentioned in patch [1/4].  We do not want conservative to shoot through
all the frequencies, its point (by default) is to slowly move through them.

By default its ten times less responsive.

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-26 10:13:21 +02:00
Alexander Clouter
2c906b317b [PATCH] cpufreq_conservative: aligning of codebase with ondemand
Since the conservative govenor was released its codebase has drifted from the
the direction and updates that have been applied to the ondemand govornor.

This patch addresses the lack of updates in that period and brings
conservative back up to date.  The resulting diff file between
cpufreq_ondemand.c and cpufreq_conservative.c is now much smaller and shows
more clearly the differences between the two.

Another reason to do this is ages ago, knowingly, I did a piss poor attempt
at making conservative less responsive by knocking up
DEF_SAMPLING_RATE_LATENCY_MULTIPLIER by two orders of magnitude.  I did fix
this ages ago but in my dis-organisation I must have toasted the diff and
left it the way it was.  About two weeks ago a user contacted me saying he
was having problems with the conservative governor with his AMD Athlon XP-M
2800+ as /sys/devices/system/cpu/cpu0/cpufreq/conservative showed
  sampling_rate_min   9950000
  sampling_rate_max   1360065408

Nine seconds to decide about changing the frequency....not too responsive :)

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-26 10:13:05 +02:00
Sam Ravnborg
bb1a813d3c [PATCH] cpufreq: fix section mismatch warnings
cpufreq are the only remaining bit to be solved for me to have a modpost
clean build for sparc64 - so I took one more look at it.
changelog entry:

Fix section mismatch warnings in cpufreq:
WARNING: drivers/cpufreq/cpufreq_stats.o - Section mismatch: reference to .init.text: from .data between 'cpufreq_stat_cpu_notifier' (at offset 0xa8) and 'notifier_policy_block'
WARNING: drivers/cpufreq/cpufreq_stats.o - Section mismatch: reference to .init.text: from .exit.text after 'cleanup_module' (at offset 0x30)

The culprint is the function: cpufreq_stat_cpu_callback
It is marked __cpuinit which get's redefined to __init in case
HOTPLUG_CPU is not enabled as per. init.h:

#ifdef CONFIG_HOTPLUG_CPU
#define __cpuinit
#else
#define __cpuinit       __init
#endif

$> grep HOTPLUG .config
CONFIG_HOTPLUG=y

But cpufreq_stat_cpu_callback() is used in:
__exit cpufreq_stats_exit()
static struct notifier_block cpufreq_stat_cpu_notifier

cpufreq_stat_cpu_notifier is again used in:
__init cpufreq_stats_init()
__exit cpufreq_stats_exit()

So in both cases used from both __init and __exit context.
Only solution seems to drop __cpuinit tag.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-03-11 13:35:43 -05:00
Dave Jones
8ff69732d4 [CPUFREQ] Fix handling for CPU hotplug
This patch adds proper logic to cpufreq driver in order to handle
CPU Hotplug.

When CPUs go on/offline, the affected CPUs data, cpufreq_policy->cpus,
is not updated properly. This causes sysfs directories and symlinks to
be in an incorrect state after few CPU on/offlines.

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-03-05 03:37:23 -05:00
Dave Jones
32ee8c3e47 [CPUFREQ] Lots of whitespace & CodingStyle cleanup.
Signed-off-by: Dave Jones <davej@redhat.com>
2006-02-28 00:43:23 -05:00
Dave Jones
7d5e350fab [CPUFREQ] Whitespace/CodingStyle cleanups
Signed-off-by: Dave Jones <davej@redhat.com>
2006-02-02 17:03:42 -05:00
Thomas Renninger
a85f7bd310 [CPUFREQ] Check whether driver init did not initialize current freq
Check whether driver init did not initialize current freq

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-02-02 16:56:41 -05:00
Dave Jones
e4472cb370 [CPUFREQ] cpufreq_notify_transition cleanup.
Introduce caching of cpufreq_cpu_data[freqs->cpu], which allows us to
make the function a lot more readable, and as a nice side-effect, it
now fits in < 80 column displays again.

Signed-off-by: Dave Jones <davej@redhat.com>
2006-01-31 15:53:55 -08:00
Thomas Renninger
c067286019 [CPUFREQ] Get rid of userspace policy struct, make userspace gov _PPC safe.
Userspace governor need not to hold it's own cpufreq_policy,
better make use of the global core policy.
Also fixes a bug in case of frequency changes via _PPC.
Old min/max values have wrongly been passed to __cpufreq_driver_target()
(kind of buffered) and when max freq was available again, only the old
max(normally lowest freq) was still active.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>

 cpufreq_userspace.c |   53 +++++++++++++++++++++++++++-------------------------
 1 files changed, 28 insertions(+), 25 deletions(-)
2006-01-27 10:36:49 -08:00
Thomas Renninger
0961dd0d21 [CPUFREQ] _PPC frequency change issues
BIOS might change frequency behind our back when BIOS changes allowed
frequencies via _PPC.  In this case cpufreq core got out of sync.
Ask driver for current freq and notify governors about a change

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-01-26 10:49:39 -08:00
Andrew Morton
f3876c1bc7 [CPUFREQ] Don't free held mutex in cpufreq_add_dev()
Make the cpufreq code play nicely with the mutex debugging code: don't free a
held mutex.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-01-18 13:53:46 -08:00
Arjan van de Ven
83933af472 [CPUFREQ] convert remaining cpufreq semaphore to a mutex
This one fell through the automation at first because it initializes the
semaphore to locked, but that's easily remedied

Signed-off-by:  Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Dave Jones <davej@redhat.com>

 drivers/cpufreq/cpufreq.c |   37 +++++++++++++++++++------------------
 include/linux/cpufreq.h   |    3 ++-
 2 files changed, 21 insertions(+), 19 deletions(-)
2006-01-18 13:53:45 -08:00
akpm@osdl.org
3fc54d37ab [CPUFREQ] Convert drivers/cpufreq semaphores to mutexes.
Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2006-01-18 13:53:45 -08:00