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2012-05-17sched: Remove stale power aware scheduling remnants and dysfunctional knobsPeter Zijlstra
It's been broken forever (i.e. it's not scheduling in a power aware fashion), as reported by Suresh and others sending patches, and nobody cares enough to fix it properly ... so remove it to make space free for something better. There's various problems with the code as it stands today, first and foremost the user interface which is bound to topology levels and has multiple values per level. This results in a state explosion which the administrator or distro needs to master and almost nobody does. Furthermore large configuration state spaces aren't good, it means the thing doesn't just work right because it's either under so many impossibe to meet constraints, or even if there's an achievable state workloads have to be aware of it precisely and can never meet it for dynamic workloads. So pushing this kind of decision to user-space was a bad idea even with a single knob - it's exponentially worse with knobs on every node of the topology. There is a proposal to replace the user interface with a single 3 state knob: sched_balance_policy := { performance, power, auto } where 'auto' would be the preferred default which looks at things like Battery/AC mode and possible cpufreq state or whatever the hw exposes to show us power use expectations - but there's been no progress on it in the past many months. Aside from that, the actual implementation of the various knobs is known to be broken. There have been sporadic attempts at fixing things but these always stop short of reaching a mergable state. Therefore this wholesale removal with the hopes of spurring people who care to come forward once again and work on a coherent replacement. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1326104915.2442.53.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-07sched: Update documentation and commentsHiroshi Shimamoto
Change sched_*.c to sched/*.c in documentation and comments. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F795CAC.9080206@ct.jp.nec.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-01-27sched: Remove sched_switchRakib Mullick
Currently we don't utilize the sched_switch field anymore. But, simply removing sched_switch field from the middle of the sched_stat output will break tools. So, to stay compatible we hardcode it to zero and remove the field from the scheduler data structures. Update the schedstat documentation accordingly. Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1327422836.27181.5.camel@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-14sched: Add documentation for bandwidth controlBharata B Rao
Basic description of usage and effect for CFS Bandwidth Control. Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184758.498036116@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-11Merge branch 'master' into for-nextJiri Kosina
Sync with Linus' tree to be able to apply pending patches that are based on newer code already present upstream.
2011-06-15Documentation: update cgroupfs mount pointJörg Sommer
According to commit 676db4af0430 ("cgroupfs: create /sys/fs/cgroup to mount cgroupfs on") the canonical mountpoint for the cgroup filesystem is /sys/fs/cgroup. Hence, this should be used in the documentation. Signed-off-by: Jörg Sommer <joerg@alea.gnuu.de> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-13doc: fix wrong arch/i386 referencesWanlong Gao
Change all "arch/i386" to "arch/x86" in Documentaion/, since the directory has changed. Also update the files which have changed their filename in the meantime accordingly. Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com> [jkosina@suse.cz: reword changelog] Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-03-31sched, doc: Beef up load balancing descriptionBorislav Petkov
Correct all function names pertaining to load balancing and explain shortly how load balancing is performed. Signed-off-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1301241433-3790-1-git-send-email-bp@alien8.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-23sched, doc: Update sched-design-CFS.txtBorislav Petkov
Correct ->dequeue_tree() thinko into sched_class->dequeue_task and drop all references to ->task_new() since it is obviously gone. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1300815978-16618-1-git-send-email-bp@amd64.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01sched, docs: Update schedstats documentation to version 15Javi Merino
Version 15 of schedstats was introduced in: 67aa0f767af4: sched: remove unused fields from struct rq and removed three unused counters in sched_yield(). Update the documentation. Signed-off-by: Javi Merino <cibervicho@gmail.com> Cc: henrix@sapo.pt Cc: rdunlap@xenotime.net Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <1296515496-8229-1-git-send-email-cibervicho@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-02Docs: typo: Complete -> CompletelyMichael Witten
Signed-off-by: Michael Witten <mfwitten@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-04-02sched: Remove USER_SCHED from documentationLi Zefan
USER_SCHED has been removed, so update the documentation accordingly. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Serge E. Hallyn <serue@us.ibm.com> LKML-Reference: <4BA9A07E.8070508@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-21sched: Documentation/sched-rt-group: Fix style issues & bump versionWolfram Sang
- add missing closing bracket - fix two 80-chars issues (as the rest of the document adheres to it) - bump a reference to kernel version, so the document does not feel aged Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1245580359-4465-1-git-send-email-w.sang@pengutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-12trivial: Miscellaneous documentation typo fixesMatt LaPlante
Fix various typos in documentation txts. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-05-29sched: fix typo in sched-rt-group.txt fileGeunSik Lim
Fix typo about static priority's range. Kernel Space User Space =============================================================== 0(high) to 98(low) user RT priority 99(high) to 1(low) with SCHED_RR or SCHED_FIFO --------------------------------------------------------------- 99 sched_priority is not used in scheduling decisions(it must be specified as 0) --------------------------------------------------------------- 100(high) to 139(low) user nice -20(high) to 19(low) --------------------------------------------------------------- 140 idle task priority --------------------------------------------------------------- * ref) http://www.kernel.org/doc/man-pages/online/pages/man2/sched_setscheduler.2.html Signed-off-by: GeunSik Lim <geunsik.lim@samsung.com> CC: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-05sched: rt: document the risk of small values in the bandwidth settingsPeter Zijlstra
Thomas noted that we should disallow sysctl_sched_rt_runtime == 0 for (!RT_GROUP) since the root group always has some RT tasks in it. Further, update the documentation to inspire clue. [ Impact: exclude corner-case sysctl_sched_rt_runtime value ] Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090505155436.863098054@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-30trivial: fix where cgroup documentation is not correctly referred toThadeu Lima de Souza Cascardo
cgroup documentation was moved to Documentation/cgroups/. There are some places that still refer to Documentation/controllers/, Documentation/cgroups.txt and Documentation/cpusets.txt. Fix those. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-03-02sched, documentation: remove old O(1) scheduler documentWang Chen
Since we don't have O(1) scheduler implementation anymore, remove the legacy doc. Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15cgroups: consolidate cgroup documentsLi Zefan
Move Documentation/cpusets.txt and Documentation/controllers/* to Documentation/cgroups/ Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-28Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits) sched: fix warning in fs/proc/base.c schedstat: consolidate per-task cpu runtime stats sched: use RCU variant of list traversal in for_each_leaf_rt_rq() sched, cpuacct: export percpu cpuacct cgroup stats sched, cpuacct: refactoring cpuusage_read / cpuusage_write sched: optimize update_curr() sched: fix wakeup preemption clock sched: add missing arch_update_cpu_topology() call sched: let arch_update_cpu_topology indicate if topology changed sched: idle_balance() does not call load_balance_newidle() sched: fix sd_parent_degenerate on non-numa smp machine sched: add uid information to sched_debug for CONFIG_USER_SCHED sched: move double_unlock_balance() higher sched: update comment for move_task_off_dead_cpu sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares sched/rt: removed unneeded defintion sched: add hierarchical accounting to cpu accounting controller sched: include group statistics in /proc/sched_debug sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER sched: clean up SCHED_CPUMASK_ALLOC ...
2008-12-09user namespaces: document CFS behaviorSerge E. Hallyn
Documented the currently bogus state of support for CFS user groups with user namespaces. In particular, all users in a user namespace should be children of the user which created the user namespace. This is yet to be implemented. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-06sched, documentation: update scheduler header file pathsRandy Dunlap
Impact: update documentation Update Documentation/scheduler/ files to reflect changed header files locations. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-30sched: remove sched-design.txt from 00-INDEXLi Zefan
Impact: remove stale documentation reference sched-design.txt has been removed. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-27sched: fix documentation reference for sched_min_granularity_nsJiri Kosina
Impact: documentation fix sched-design-CFS.txt wrongly references sched_granularity_ns sysctl, as its name in fact is sched_min_granularity_ns. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23CFS scheduler: documentation about scheduling policiesMartin Steigerwald
The documentation about the CFS scheduler is scarse when it comes to scheduling policies. This patch adds a chapter about the scheduling policies it supports. Peter Zijlstra provided most of the information for it in http://marc.info/?l=linux-kernel&m=122210038326356&w=2 Signed-off-by: Martin Steigerwald <ms@teamix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21sched: new documentation about CFSClaudio Scordino
Rewrite of the CFS documentation - because the old one was sorely out-dated. Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-18sched: fix typo in Documentation/scheduler/sched-rt-group.txtHiroshi Shimamoto
Fix minor typos. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-06sched: update the sched-domains debug documentationGautham R Shenoy
SCHED_DOMAIN_DEBUG mentioned in the Documentation for sched-domains for enabling sched-domains debugging doesn't exist anymore. Update the documentation to reflect the correct way of enabling sched-domain debugging. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-05sched: remove old sched docIngo Molnar
Fabio Checconi noticed that Documentation/scheduler/sched-design.txt was a stale copy of the old scheduler. Remove it. Reported-by: Fabio Checconi <fabio@gandalf.sssup.it> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19sched: better rt-group documentationViktor Radnai
Viktor was nice enough to enhance the document based on my replies to his questions on the subject. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-11Move sched-rt-group.txt to scheduler/J. Bruce Fields
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2008-03-10Typo in Documentation/scheduler/sched-stats.txtMasatake YAMATO
I have found a very small typo in Documentation/scheduler/sched-stats.txt. See the end of this mail. Signed-off-by: Masatake YAMATO <yamato@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07Documentation: create new scheduler/ subdirectoryJ. Bruce Fields
The top-level Documentation/ directory is unmanageably large, so we should take any obvious opportunities to move stuff into subdirectories. These sched-*.txt files seem an obvious easy case. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>