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* [PATCH] x86_64: Move ondemand timer into own work queueAndi Kleen2006-05-08
| | | | | | | | | | | | | | | | 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>
* [PATCH] Remove __devinit and __cpuinit from notifier_call definitionsChandra Seetharaman2006-04-26
| | | | | | | | | | | | | 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>
* [CPUFREQ] drivers/cpufreq/cpufreq.c: static functions mustn't be exportedAdrian Bunk2006-04-18
| | | | | | | 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>
* [CPUFREQ] If max_freq got reduced (e.g. by _PPC) a write to sysfs ↵Thomas Renninger2006-04-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] Update LART site URLErik Mouw2006-04-03
| | | | | | | | | | 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>
* [CPUFREQ] Remove pointless check in conservative governor.Dave Jones2006-04-01
| | | | | | < 0 checks on unsigned variables are pointless. Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] trailing whitespace removal de-jour.Dave Jones2006-03-29
| | | | Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] extra debugging in cpufreq_add_dev()Dave Jones2006-03-29
| | | | | Snipped from an otherwise rejected patch by Jan Beulich <jbeulich@novell.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] cpufreq_conservative: keep ignore_nice_load and freq_step values ↵Mattia Dongili2006-03-28
| | | | | | | | | | 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/cpufreq-2.6Dave Jones2006-03-27
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| * [PATCH] cpufreq_ondemand: add range checkDominik Brodowski2006-03-26
| | | | | | | | | | | | | | 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>
| * [PATCH] cpufreq_ondemand: keep ignore_nice_load value when it is reselectedEric Piel2006-03-26
| | | | | | | | | | | | | | | | | | | | | | 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>
| * [PATCH] cpufreq_ondemand: Warn if it cannot run due to too long transition ↵Eric Piel2006-03-26
| | | | | | | | | | | | | | | | | | | | | | 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>
| * [PATCH] cpufreq_conservative: alternative initialise approachAlexander Clouter2006-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * [PATCH] cpufreq_conservative: make for_each_cpu() safeAlexander Clouter2006-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * [PATCH] cpufreq_conservative: alter default responsivenessAlexander Clouter2006-03-26
| | | | | | | | | | | | | | | | | | | | | | 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>
| * [PATCH] cpufreq_conservative: aligning of codebase with ondemandAlexander Clouter2006-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | [PATCH] Notifier chain update: API changesAlan Stern2006-03-27
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] cpufreq: fix section mismatch warningsSam Ravnborg2006-03-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] Fix handling for CPU hotplugDave Jones2006-03-05
| | | | | | | | | | | | 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>
* [CPUFREQ] Lots of whitespace & CodingStyle cleanup.Dave Jones2006-02-28
| | | | Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Whitespace/CodingStyle cleanupsDave Jones2006-02-02
| | | | Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Check whether driver init did not initialize current freqThomas Renninger2006-02-02
| | | | | | | 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>
* [CPUFREQ] cpufreq_notify_transition cleanup.Dave Jones2006-01-31
| | | | | | | | 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>
* [CPUFREQ] Get rid of userspace policy struct, make userspace gov _PPC safe.Thomas Renninger2006-01-27
| | | | | | | | | | | | | | | | 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(-)
* [CPUFREQ] _PPC frequency change issuesThomas Renninger2006-01-26
| | | | | | | | | | 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>
* [CPUFREQ] Don't free held mutex in cpufreq_add_dev()Andrew Morton2006-01-18
| | | | | | | | | 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>
* [CPUFREQ] convert remaining cpufreq semaphore to a mutexArjan van de Ven2006-01-18
| | | | | | | | | | | | 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(-)
* [CPUFREQ] Convert drivers/cpufreq semaphores to mutexes.akpm@osdl.org2006-01-18
| | | | | | | | | | | | 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>
* [PATCH] Unlinline a bunch of other functionsArjan van de Ven2006-01-14
| | | | | | | | | | | 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>
* [CPUFREQ] CPU frequency display in /proc/cpuinfoVenkatesh Pallipadi2005-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] cpufreq_conservative/ondemand: invert meaning of 'ignore nice'Alexander Clouter2005-12-01
| | | | | | | | | | | | | | | | | | 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>
* [PATCH] clean up lock_cpu_hotplug() in cpufreqAshok Raj2005-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] cpufreq: silence cpufreq for UPGrant Coady2005-11-22
| | | | | | | | | | 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>
* [PATCH] cpu hotplug: fix locking in cpufreq driversAshok Raj2005-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreqLinus Torvalds2005-11-07
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| * [CPUFREQ] Fix up compile of cpufreq_statsDave Jones2005-11-02
| | | | | | | | | | | | Whoops, I lost a hunk of the last patch somehow. Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] Check return value of cpufreq_cpu_get in cpufreq_statsDave Jones2005-10-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * [CPUFREQ] kzalloc conversions for cpufreq core.Dave Jones2005-10-20
| | | | | | | | Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] Avoid the ondemand cpufreq governor to use a too high frequency ↵Dave Jones2005-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | [PATCH] create and destroy cpufreq sysfs entries based on cpu notifiersAshok Raj2005-10-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | [PATCH] Remove cpu_sys_devices in cpufreq subsystem.Ashok Raj2005-10-30
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | [PATCH] cpufreq: SMP fix for conservative governorDave Jones2005-10-27
|/ | | | | | | | | | | | 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>
* [CPUFREQ] Bugfix: Call driver exit in cpufreq_add_dev error pathVenkatesh Pallipadi2005-09-01
| | | | | | | | | 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>
* Here are two possible cleanups in cpufreq.c:Dave Jones2005-07-28
| | | | | | | | * 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>
* [PATCH] pm: fix u32 vs. pm_message_t confusion in cpufreqBernard Blackham2005-07-07
| | | | | | | | | | 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>
* [PATCH] sysfs: (rest) if show/store is missing return -EIODmitry Torokhov2005-06-20
| | | | | | | | | 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>
* [PATCH] cpufreq-stats driver updatesVenkatesh Pallipadi2005-05-31
| | | | | | | | | | | 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>
* [CPUFREQ] ondemand governor default sampling downfactor as 1Dave Jones2005-05-31
| | | | | | | | | | | [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>
* [CPUFREQ] ondemand governor automatic downscalingDave Jones2005-05-31
| | | | | | | | | | | | | | | [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>
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