summaryrefslogtreecommitdiffstats
path: root/Documentation/cpu-freq (follow)
Commit message (Collapse)AuthorAgeFilesLines
* [CPUFREQ] Processor Clocking Control interface driverNaga Chumbalkar2010-01-131-0/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Processor Clocking Control (PCC) is an interface between the BIOS and OSPM. Based on the server workload, OSPM can request what frequency it expects from a logical CPU, and the BIOS will achieve that frequency transparently. This patch introduces driver support for PCC. OSPM uses the PCC driver to communicate with the BIOS via the PCC interface. There is a Documentation file that provides a link to the PCC Specification, and also provides a summary of the PCC interface. Currently, certain HP ProLiant platforms implement the PCC interface. However, any platform whose BIOS implements the PCC Specification, can utilize this driver. V2 --> V1 changes (based on Dominik's suggestions): - Removed the dependency on CPU_FREQ_TABLE - "cpufreq_stats" will no longer PANIC. Actually, it will not load anymore because it is not applicable. - Removed the sanity check for target frequency in the ->target routine. NOTE: A patch to sanitize the target frequency requested by "ondemand" is needed to ensure that the target freq < policy->min. Can this driver be queued up for the 2.6.33 tree? Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] fix default value for ondemand governorMike Frysinger2010-01-131-2/+2
| | | | | Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Dave Jones <davej@redhat.com>
* [ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interfaceThomas Renninger2009-11-241-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This interface is mainly intended (and implemented) for ACPI _PPC BIOS frequency limitations, but other cpufreq drivers can also use it for similar use-cases. Why is this needed: Currently it's not obvious why cpufreq got limited. People see cpufreq/scaling_max_freq reduced, but this could have happened by: - any userspace prog writing to scaling_max_freq - thermal limitations - hardware (_PPC in ACPI case) limitiations Therefore export bios_limit (in kHz) to: - Point the user that it's the BIOS (broken or intended) which limits frequency - Export it as a sysfs interface for userspace progs. While this was a rarely used feature on laptops, there will appear more and more server implemenations providing "Green IT" features like allowing the service processor to limit the frequency. People want to know about HW/BIOS frequency limitations. All ACPI P-state driven cpufreq drivers are covered with this patch: - powernow-k8 - powernow-k7 - acpi-cpufreq Tested with a patched DSDT which limits the first two cores (_PPC returns 1) via _PPC, exposed by bios_limit: # echo 2200000 >cpu2/cpufreq/scaling_max_freq # cat cpu*/cpufreq/scaling_max_freq 2600000 2600000 2200000 2200000 # #scaling_max_freq shows general user/thermal/BIOS limitations # cat cpu*/cpufreq/bios_limit 2600000 2600000 2800000 2800000 # #bios_limit only shows the HW/BIOS limitation CC: Pallipadi Venkatesh <venkatesh.pallipadi@intel.com> CC: Len Brown <lenb@kernel.org> CC: davej@codemonkey.org.uk CC: linux@dominikbrodowski.net Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Document units for transition latencyMark Brown2009-11-241-3/+3
| | | | | | | They're documented in the header but not in Documentation. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] update Doc for cpuinfo_cur_freq and scaling_cur_freqNaga Chumbalkar2009-09-011-2/+7
| | | | | | | | | | | | | | | | | | | | | | | I think the way "cpuinfo_cur_info" and "scaling_cur_info" are defined under ./Documentation/cpu-freq/user-guide.txt can be enhanced. Currently, they are both defined the same way: "Current speed/frequency" of the CPU, in KHz". Below is a patch that distinguishes one from the other. Regards, - naga - ----------------------------------------- Update description for "cpuinfo_cur_freq" and "scaling_cur_freq". Some of the wording is drawn from comments found in ./drivers/cpufreq/cpufreq.c: cpufreq_out_of_sync(): * @old_freq: CPU frequency the kernel thinks the CPU runs at * @new_freq: CPU frequency the CPU actually runs at Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] minor correction to cpu-freq documentationChumbalkar Nagananda2009-06-152-2/+1
| | | | | | | | I have been reading the documentation for cpufreq closely. Found a couple of minor errors in the Documentation. Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is usefulThomas Renninger2009-06-151-12/+14
| | | | | | | | Update the documentation accordingly. Cleanup and use printk_once. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictionsThomas Renninger2009-02-251-1/+13
| | | | | | | | Limit sampling rate to transition_latency * 100 or kernel limits. If sampling_rate is tried to be set too low, set the lowest allowed value. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] ondemand/conservative: deprecate sampling_rate{min,max}Thomas Renninger2009-02-251-2/+8
| | | | | | | The same info can be obtained via the transition_latency sysfs file Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Introduce ↵Thomas Renninger2009-02-251-0/+12
| | | | | | | | | | | | | | | /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_transition_latency It's not only useful for the ondemand and conservative governors, but also for userspace daemons to know about the HW transition latency of the CPU. It is especially useful for userspace to know about this value when the ondemand or conservative governors are run. The sampling rate control value depends on it and for userspace being able to set sane tuning values there it has to know about the transition latency. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* ACPI: cpufreq: Remove deprecated /proc/acpi/processor/../performance proc ↵Thomas Renninger2009-02-041-16/+0
| | | | | | | | | | | | | entries They were long enough set deprecated... Update Documentation/cpu-freq/users-guide.txt: The deprecated files listed there seen not to exist for some time anymore already. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Len Brown <len.brown@intel.com>
* doc: Update sh cpufreq documentation.Paul Mundt2008-12-221-4/+2
| | | | | | | The sh cpufreq driver is no longer limited to just the SH-3 and SH-4, update the documentation to reflect this fact accordingly. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* [CPUFREQ] Documentation: Add Blackfin to list of supported processorsRobin Getz2008-11-251-0/+12
| | | | | | Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: Bryan Wu <cooloney@kernel.org> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] correct broken links and email addressesNémeth Márton2008-10-091-6/+4
| | | | | | | | Replace the no longer working links and email address in the documentation and in source code. Signed-off-by: Márton Németh <nm127@freemail.hu> Signed-off-by: Dave Jones <davej@redhat.com>
* Documentation cleanup: trivial misspelling, punctuation, and grammar ↵Matt LaPlante2008-07-261-1/+1
| | | | | | | | corrections. Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CPUFREQ] Remove documentation of removed ondemand tunable.Dave Jones2008-05-211-8/+0
| | | | | | | sampling_down_factor was removed in ccb2fe209dac9ff67f6351e783e610073afaaeaf back in June 2006. Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] document the currently undocumented parts of the sysfs interfaceDarrick J. Wong2008-04-281-0/+14
| | | | | | | | | | There is a description of some of the sysfs files. However, there are some that are not mentioned in the documentation, so add them to the user's guide. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
* [ARM] pxa: add cpufreq supportRussell King2008-01-261-0/+1
| | | | | | | There have been patches hanging around for ages to add support for cpufreq to PXA255 processors. It's about time we applied one. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* misc doc and kconfig typosMatt LaPlante2007-05-091-1/+1
| | | | | | | Fix various typos in kernel docs and Kconfigs, 2.6.21-rc4. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Merge ../linusDave Jones2006-12-121-2/+2
|\ | | | | | | | | | | Conflicts: drivers/cpufreq/cpufreq.c
| * Fix typos in /Documentation : MiscMatt LaPlante2006-11-301-2/+2
| | | | | | | | | | | | | | | | | | This patch fixes typos in various Documentation txts. The patch addresses some misc words. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* | [CPUFREQ] Documentation fixDominik Brodowski2006-10-161-1/+1
|/ | | | | | | Fix reference to where the code actually is. Noted by Hero Wanders. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Dave Jones <davej@redhat.com>
* Fix typos in Documentation/: 'S'Matt LaPlante2006-10-031-4/+4
| | | | | | | | | | This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letter 'S'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Alan Cox <alan@redhat.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Fix typos in Documentation/: 'N'-'P'Matt LaPlante2006-10-031-4/+4
| | | | | | | | | This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'N'-'P'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Fix typos in Documentation/: 'H'-'M'Matt LaPlante2006-10-031-1/+1
| | | | | | | | | This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'H'-'M'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Fix typos in Documentation/: 'F'-'G'Matt LaPlante2006-10-032-2/+2
| | | | | | | | This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'F'-'G'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [CPUFREQ] return error when failing to set minfreqMattia Dongili2006-08-011-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> --
* [CPUFREQ] Update LART site URLErik Mouw2006-04-031-1/+1
| | | | | | | | | | 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>
* [PATCH] cpufreq: documentation for 'ondemand' and 'conservative'Alexander Clouter2005-12-011-3/+59
| | | | | | | | | Added a more verbose entry for the 'ondemend' governor and an entry for the 'conservative' governor to the documentation. 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] Spelling fixes for Documentation/Tobias Klauser2005-09-101-1/+1
| | | | | | | | | | | | | | | | | The attached patch fixes the following spelling errors in Documentation/ - double "the" - Several misspellings of function/functionality - infomation - memeory - Recieved - wether and possibly others which I forgot ;-) Trailing whitespaces on the same line as the typo are also deleted. Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch> Signed-off-by: Domen Puncer <domen@coderock.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpufreq: governors documentation fixesNico Golde2005-06-261-2/+12
| | | | | | | | | | | | I corrected a small error and enhanced the govenor.txt file with the ondemand daemon because the kernel configs link to the documentation but ondemand wasn't documentated. Feel free to include the patch in the attachment. Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpufreq-stats driver documentationVenkatesh Pallipadi2005-06-011-0/+128
| | | | | | | | Documentation for cpufreq stats. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-177-0/+767
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!
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 22:44:38 +0100