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>
Peter Zijlstraauthored and Ingo Molnarcommited 2012-05-17 13:48:56 +02:00
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>
Rakib Mullickauthored and Ingo Molnarcommited 2012-01-27 13:28:53 +01:00
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>
Bharata B Raoauthored and Ingo Molnarcommited 2011-08-14 12:03:58 +02:00
According to commit 676db4af04 ("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>
Jörg Sommerauthored and Linus Torvaldscommited 2011-06-15 21:52:50 -07:00
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>
Wanlong Gaoauthored and Jiri Kosinacommited 2011-06-13 13:43:05 +02:00
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>
Borislav Petkovauthored and Ingo Molnarcommited 2011-03-31 13:00:35 +02:00
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>
Borislav Petkovauthored and Ingo Molnarcommited 2011-03-23 14:09:41 +01:00
Version 15 of schedstats was introduced in:
67aa0f767a: 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>
Javi Merinoauthored and Ingo Molnarcommited 2011-02-01 09:07:13 +01:00
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>
Li Zefanauthored and Ingo Molnarcommited 2010-04-02 20:12:01 +02:00
- 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>
Wolfram Sangauthored and Ingo Molnarcommited 2009-06-21 13:12:46 +02:00
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>
GeunSik Limauthored and Ingo Molnarcommited 2009-05-29 16:21:09 +02:00
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>
Peter Zijlstraauthored and Ingo Molnarcommited 2009-05-05 20:07:57 +02:00
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>
Thadeu Lima de Souza Cascardoauthored and Jiri Kosinacommited 2009-03-30 15:22:02 +02:00
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>
Wang Chenauthored and Ingo Molnarcommited 2009-03-02 12:02:52 +01:00
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>
Serge E. Hallynauthored and James Morriscommited 2008-12-09 09:25:53 +11:00
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>
Li Zefanauthored and Ingo Molnarcommited 2008-10-30 11:37:58 +01:00
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>
Jiri Kosinaauthored and Ingo Molnarcommited 2008-10-27 18:49:19 +01:00
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>
Martin Steigerwaldauthored and Ingo Molnarcommited 2008-09-23 13:49:44 +02:00
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>
Claudio Scordinoauthored and Ingo Molnarcommited 2008-08-21 08:17:24 +02:00
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>
Gautham R Shenoyauthored and Ingo Molnarcommited 2008-06-06 15:19:39 +02:00
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>
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>
Viktor Radnaiauthored and Ingo Molnarcommited 2008-04-19 19:45:01 +02:00
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>
Masatake YAMATOauthored and Linus Torvaldscommited 2008-03-10 18:01:19 -07:00
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>
J. Bruce Fieldsauthored and Linus Torvaldscommited 2008-02-07 08:42:17 -08:00
Peter Zijlstra
authored and
Ingo Molnar
commited 
Hiroshi Shimamoto
authored and
Rakib Mullick
authored and
Ingo Molnar
commited 
Bharata B Rao
authored and
Jiri Kosina
commited 
Jörg Sommer
authored and
Linus Torvalds
commited 
Wanlong Gao
authored and
Borislav Petkov
authored and
Borislav Petkov
authored and
Javi Merino
authored and
Michael Witten
authored and
Li Zefan
authored and
Wolfram Sang
authored and
Matt LaPlante
authored and
GeunSik Lim
authored and
Peter Zijlstra
authored and
Thadeu Lima de Souza Cascardo
authored and
Wang Chen
authored and
Serge E. Hallyn
authored and
James Morris
commited 
Randy Dunlap
authored and
Martin Steigerwald
authored and
Claudio Scordino
authored and
Gautham R Shenoy
authored and
Viktor Radnai
authored and
J. Bruce Fields
authored and
Jonathan Corbet
commited 
Masatake YAMATO
authored and
Linus Torvalds
commited