Commit Graph

105 Commits

Author SHA1 Message Date
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
Arjan van de Ven
858119e159 [PATCH] Unlinline a bunch of other functions
Remove the "inline" keyword from a bunch of big functions in the kernel with
the goal of shrinking it by 30kb to 40kb

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 18:27:06 -08:00
Venkatesh Pallipadi
95235ca2c2 [CPUFREQ] CPU frequency display in /proc/cpuinfo
What is the value shown in "cpu MHz" of /proc/cpuinfo when CPUs are capable of
changing frequency?

Today the answer is: It depends.
On i386:
SMP kernel - It is always the boot frequency
UP kernel - Scales with the frequency change and shows that was last set.

On x86_64:
There is one single variable cpu_khz that gets written by all the CPUs. So,
the frequency set by last CPU will be seen on /proc/cpuinfo of all the
CPUs in the system. What you see also depends on whether you have constant_tsc
capable CPU or not.

On ia64:
It is always boot time frequency of a particular CPU that gets displayed.

The patch below changes this to:
Show the last known frequency of the particular CPU, when cpufreq is present. If
cpu doesnot support changing of frequency through cpufreq, then boot frequency
will be shown. The patch affects i386, x86_64 and ia64 architectures.

Signed-off-by: Venkatesh Pallipadi<venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-12-06 19:35:11 -08:00
Alexander Clouter
001893cda2 [PATCH] cpufreq_conservative/ondemand: invert meaning of 'ignore nice'
The use of the 'ignore_nice' sysfs file is confusing to anyone using it.
This removes the sysfs file 'ignore_nice' and in its place creates a
'ignore_nice_load' entry that defaults to '0'; meaning nice'd processes
_are_ counted towards the 'business' calculation.

WARNING: this obvious breaks any userland tools that expected ignore_nice'
to exist, to draw attention to this fact it was concluded on the mailing
list that the entry should be removed altogether so the userland app breaks
and so the author can build simple to detect workaround.  Having said that
it seems currently very few tools even make use of this functionality; all
I could find was a Gentoo Wiki entry.

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-12-01 01:23:23 -08:00
Ashok Raj
a9d9baa1e8 [PATCH] clean up lock_cpu_hotplug() in cpufreq
There are some callers in cpufreq hotplug notify path that the lowest
function calls lock_cpu_hotplug().  The lock is already held during
cpu_up() and cpu_down() calls when the notify calls are broadcast to
registered clients.

Ideally if possible, we could disable_preempt() at the highest caller and
make sure we dont sleep in the path down in cpufreq->driver_target() calls
but the calls are so intertwined and cumbersome to cleanup.

Hence we consistently use lock_cpu_hotplug() and unlock_cpu_hotplug() in
all places.

 - Removed export of cpucontrol semaphore and made it static.
 - removed explicit uses of up/down with lock_cpu_hotplug()
   so we can keep track of the the callers in same thread context and
   just keep refcounts without calling a down() that causes a deadlock.
 - Removed current_in_hotplug() uses
 - Removed PF_HOTPLUG_CPU in sched.h introduced for the current_in_hotplug()
   temporary workaround.

Tested with insmod of cpufreq_stat.ko, and logical online/offline
to make sure we dont have any hang situations.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Cc: Zwane Mwaikambo <zwane@linuxpower.ca>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-28 14:42:23 -08:00
Grant Coady
e738cf6d03 [PATCH] cpufreq: silence cpufreq for UP
drivers/cpufreq/cpufreq.c: In function `cpufreq_remove_dev':
drivers/cpufreq/cpufreq.c:696: warning: unused variable `cpu_sys_dev'

Signed-off-by: Grant Coady <gcoady@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-22 09:13:44 -08:00
Ashok Raj
90d45d17f3 [PATCH] cpu hotplug: fix locking in cpufreq drivers
When calling target drivers to set frequency, we take cpucontrol lock.
When we modified the code to accomodate CPU hotplug, there was an attempt
to take a double lock of cpucontrol leading to a deadlock.  Since the
current thread context is already holding the cpucontrol lock, we dont need
to make another attempt to acquire it.

Now we leave a trace in current->flags indicating current thread already is
under cpucontrol lock held, so we dont attempt to do this another time.

Thanks to Andrew Morton for the beating:-)

From: Brice Goglin <Brice.Goglin@ens-lyon.org>

  Build fix

(akpm: this patch is still unpleasant.  Ashok continues to look for a cleaner
solution, doesn't he?  ;))

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:50 -08:00
Linus Torvalds
dad2ad82c5 Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq 2005-11-07 13:28:20 -08:00
Dave Jones
b7fb358c7c [CPUFREQ] Fix up compile of cpufreq_stats
Whoops, I lost a hunk of the last patch somehow.

Signed-off-by: Dave Jones <davej@redhat.com>
2005-11-01 23:13:45 -08:00
Ashok Raj
c32b6b8e52 [PATCH] create and destroy cpufreq sysfs entries based on cpu notifiers
cpufreq entries in sysfs should only be populated when CPU is online state.
 When we either boot with maxcpus=x and then boot the other cpus by echoing
to sysfs online file, these entries should be created and destroyed when
CPU_DEAD is notified.  Same treatement as cache entries under sysfs.

We place the processor in the lowest frequency, so hw managed P-State
transitions can still work on the other threads to save power.

Primary goal was to just make these directories appear/disapper dynamically.

There is one in this patch i had to do, which i really dont like myself but
probably best if someone handling the cpufreq infrastructure could give
this code right treatment if this is not acceptable.  I guess its probably
good for the first cut.

- Converting lock_cpu_hotplug()/unlock_cpu_hotplug() to disable/enable preempt.
  The locking was smack in the middle of the notification path, when the
  hotplug is already holding the lock. I tried another solution to avoid this
  so avoid taking locks if we know we are from notification path. The solution
  was getting very ugly and i decided this was probably good for this iteration
  until someone who understands cpufreq could do a better job than me.

(akpm: export cpucontrol to GPL modules: drivers/cpufreq/cpufreq_stats.c now
does lock_cpu_hotplug())

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Zwane Mwaikambo <zwane@holomorphy.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:14 -08:00
Ashok Raj
d434fca737 [PATCH] Remove cpu_sys_devices in cpufreq subsystem.
cpu_sys_devices is redundant with the new API get_cpu_sysdev().  So nuking
this usage since its not needed.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Zwane Mwaikambo <zwane@holomorphy.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:14 -08:00
Dave Jones
9273214409 [PATCH] cpufreq: SMP fix for conservative governor
Don't try to access not-present CPUs.  Conservative governor will always
oops on SMP without this fix.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=4781

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-27 16:29:24 -07:00
Dave Jones
bc7b26fd7c [CPUFREQ] Check return value of cpufreq_cpu_get in cpufreq_stats
This fixes an issue found in drivers/cpufreq/cpufreq_stats.c by Coverity.

Error reported:
CID: 2642
Checker: NULL_RETURNS (help)
File: /export2/p4-coverity/mc2/linux26/drivers/cpufreq/cpufreq_stats.c
Function: cpufreq_stats_create_table
Description: Dereferencing NULL value "data"

Patch description:
 The return of cpufreq_cpu_get can be NULL, check return code and return
 -EINVAL if it is NULL.

Signed-off-by: Jayachandran C. <c.jayachandran at gmail.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-10-27 16:02:06 -07:00
Dave Jones
e98df50c52 [CPUFREQ] kzalloc conversions for cpufreq core.
Signed-off-by: Dave Jones <davej@redhat.com>
2005-10-20 15:17:43 -07:00
Dave Jones
df8b59be09 [CPUFREQ] Avoid the ondemand cpufreq governor to use a too high frequency for stats.
The problem is in the ondemand governor, there is a periodic measurement
of the CPU usage. This CPU usage is updated by the scheduler after every
tick (basically, by adding 1 either to "idle" or to "user" or to
"system"). So if the frequency of the governor is too high, the stat
will be meaningless (as mostly no number have changed).

So this patch checks that the measurements are separated by at least 10
ticks. It means that by default, stats will have about 5% error (20
ticks). Of course those numbers can be argued but, IMHO, they look sane.
The patch also includes a small clean-up to check more explictly the
result of the conversion from ns to µs being null.

Let's note that (on x86) this has never been really needed before 2.6.13
because HZ was always 1000. Now that HZ can be 100, some CPU might be
affected by this problem. For instance when HZ=100, the centrino ,which
has a 10µs transition latency, would lead to the governor allowing to
read stats every tick (10ms)!

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-09-20 12:39:35 -07:00
Venkatesh Pallipadi
8085e1f1f0 [CPUFREQ] Bugfix: Call driver exit in cpufreq_add_dev error path
A minor fix for cpufreq_add_dev() error path. We need to call driver->exit()
if driver_init() call has succeeded.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-08-31 22:21:28 -07:00
Dave Jones
cc993cab02 Here are two possible cleanups in cpufreq.c:
* ret has no need to be unsigned in cpufreq_driver_target()
* ret has no need to be initialized in __cpufreq_governor()

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-07-28 09:43:56 -07:00
Bernard Blackham
e00d9967e3 [PATCH] pm: fix u32 vs. pm_message_t confusion in cpufreq
Fix u32 vs pm_message_t confusion in cpufreq.

Signed-off-by: Bernard Blackham <bernard@blackham.com.au>
Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07 18:23:43 -07:00
Dmitry Torokhov
70f2817a43 [PATCH] sysfs: (rest) if show/store is missing return -EIO
sysfs: fix the rest of the kernel so if an attribute doesn't
       implement show or store method read/write will return
       -EIO instead of 0 or -EINVAL or -EPERM.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:03 -07:00
Venkatesh Pallipadi
58f1df2540 [PATCH] cpufreq-stats driver updates
Changes to the cpufreq stats driver:
* Changes the way P-state transition table looks in /sysfs providing more
  clear output
* Changes the time unit in the output from HZ to clock_t

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:04:05 -07:00
Dave Jones
e131832ca7 [CPUFREQ] ondemand governor default sampling downfactor as 1
[PATCH] [5/5] ondemand governor default sampling downfactor as 1

Make default sampling downfactor 1.
This works better with earlier auto downscaling change in ondemand governor.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:50 -07:00
Dave Jones
c29f140309 [CPUFREQ] ondemand governor automatic downscaling
[PATCH] [4/5] ondemand governor automatic downscaling

Here is a change of policy for the ondemand governor. The modification
concerns the frequency downscaling. Instead of decreasing to a lower
frequency when the CPU usage is under 20%, this new policy automatically
scales to the optimal frequency. The optimal frequency being the lowest
frequency which provides enough power to not trigger the upscaling policy.

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:50 -07:00
Dave Jones
9c7d269b9b [CPUFREQ] ondemand,conservative governor idle_tick clean-up
[PATCH] [3/5] ondemand,conservative governor idle_tick clean-up

Ondemand and conservative governor clean-up, it factorises the idle ticks 
measurement.

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:49 -07:00
Dave Jones
790d76fa97 [CPUFREQ] ondemand,conservative governor store the idle ticks for all cpus
[PATCH] [2/5] ondemand,conservative governor store the idle ticks for all cpus

Ondemand, conservative governor did not store prev_cpu_idle_up into 
prev_cpu_idle_down for other CPUs than the current CPU.

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:49 -07:00
Dave Jones
dac1c1a562 [CPUFREQ] ondemand,conservative minor bug-fix and cleanup
[PATCH] [1/5] ondemand,conservative minor bug-fix and cleanup

Attached patch fixes some minor issues with Alexander's patch and related
cleanup in both ondemand and conservative governor.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:49 -07:00
Dave Jones
1206aaac28 [CPUFREQ] Allow ondemand stepping to be changed by user.
Adds support so that the cpufreq change stepping is no longer fixed at 5% and
can be changed dynamically by the user

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:48 -07:00
Dave Jones
c11420a616 [CPUFREQ] Prevents un-necessary cpufreq changes if we are already at min/max
Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:48 -07:00
Dave Jones
3d5ee9e55d [CPUFREQ] Add support to cpufreq_ondemand to ignore 'nice' cpu time
Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
Dave Jones
b9170836d1 [CPUFREQ] Conservative cpufreq governer
A new cpufreq module, based on the ondemand one with my additional patches
just posted.  This one is more suitable for battery environments where its
probably more appealing to have the cpu freq gracefully increase and decrease
rather than flip between the min and max freq's.

N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency
between min and max freq transition, due to the step-by-step requirements
(200MHz IIRC)"; so AMD64 users would probably benefit from this too.

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
Dave Jones
7f335d4ef2 [CPUFREQ] make cpufreq_gov_dbs static
This patch makes a needlessly global and EXPORT_SYMBOL'ed struct static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:46 -07:00
Dave Jones
3310010818 [CPUFREQ] Add warning comment about default governors.
This comes up time and time again. Until its fixed, place this
comment in the Kconfig which should stem the flow of resubmissions.

Signed-off-by: Rob Weryk <rjweryk@uwo.ca>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:44 -07:00
Dave Jones
6fe711658f [CPUFREQ] ondemand: trivial clean-ups
Trivial ondemand governor clean-ups:
- change from sampling_rate_in_HZ() to the official function
usecs_to_jiffies().
- use for_each_online_cpu() to instead of using "if (cpu_online(i))"

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:44 -07:00
Dave Jones
78ee998fd4 [CPUFREQ] cpufreq-core: reduce warning messages.
cpufreq core is printing out messages at KERN_WARNING level that the core
recovers from without intervention, and that the system administrator can
do nothing about.  Patch below reduces the severity of these messages to
debug.

Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:43 -07:00
Benjamin Herrenschmidt
ac09f698f1 [PATCH] cpufreq annoying warning fix
The cpufreq core patch I sent earlier got only half-applied.  I added a
flag to let the low level driver disable an annoying warning on
suspend/resume that is normal on ppc, but the "resume" part of it wasn't
applied.

This just adds back that missing bit.  The original patch also reworked
the resume() function to avoid nesting too many if () statements along
the way I did the suspend() one, but I didn't include that in the patch
below.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-02 08:15:22 -07:00
Benjamin Herrenschmidt
42d4dc3f4e [PATCH] Add suspend method to cpufreq core
In order to properly fix some issues with cpufreq vs. sleep on
PowerBooks, I had to add a suspend callback to the pmac_cpufreq driver.
I must force a switch to full speed before sleep and I switch back to
previous speed on resume.

I also added a driver flag to disable the warnings in suspend/resume
since it is expected in this case to have different speed (and I want it
to fixup the jiffies properly).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-29 07:40:12 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00