Ingo Molnar announced version 20 of his Completely Fair Scheduler [1] patchset, offering further cleanups for the new scheduler code that will be part of the upcoming 2.6.23 [2] kernel, "there have been lots of small regression fixes, speedups, debug enhancements and tidy-ups - many of which can be user-visible." Ingo went on to summarize:
"There are nearly 100 changes - they do add up to a significant total linecount change. There was no crash bug or hang bug found in the CFS code since v19 was released. (in fact the last crash/hang bug in CFS was found and fixed in v7, more than 3 months ago, and even that crash only happened in an uncommon sw-suspend setup, not during normal use. So CFS has turned out to be a pretty robust codebase.) Nevertheless, if you had any problems (performance or behavioral) with v19 it's worth checking v20 out - and if v19 worked great for you it's worth checking out that v20 still works great =B-)"
From: Ingo Molnar [3] [email blocked]
To: linux-kernel
Subject: [patch] CFS scheduler, -v20, for v2.6.22.5, v2.6.21.7, v2.6.20.16
Date: Thu, 23 Aug 2007 11:43:46 +0200
By popular demand, here is release -v20 of the CFS scheduler. It is a
full backport of the latest & greatest v2.6.23-rc3 CFS code to
v2.6.22.5, v2.6.21.7 and v2.6.20.16. The patches can be downloaded from
the usual place:
http://people.redhat.com/mingo/cfs-scheduler/ [4]
Changes since -v19: there have been lots of small regression fixes,
speedups, debug enhancements and tidy-ups - many of which can be
user-visible.
See the detailed shortlog below - there are nearly 100 changes - they do
add up to a significant total linecount change. There was no crash bug
or hang bug found in the CFS code since v19 was released. (in fact the
last crash/hang bug in CFS was found and fixed in v7, more than 3 months
ago, and even that crash only happened in an uncommon sw-suspend setup,
not during normal use. So CFS has turned out to be a pretty robust
codebase.)
Nevertheless, if you had any problems (performance or behavioral) with
v19 it's worth checking v20 out - and if v19 worked great for you it's
worth checking out that v20 still works great =B-)
Also, the backported CFS scheduler enables people to test suspected
scheduler regressions on older codebases too, to filter out the effects
of other changes.
v20 has been build and boot tested on both 32-bit and 64-bit x86, ontop
of all 3 backport kernel bases. As usual, any sort of feedback,
bugreport, fix and suggestion is more than welcome!
Ingo
------------------->
Adrian Bunk (1):
sched: make global code static
Al Viro (1):
take sched_debug.c out of nasal demon territory
Alexey Dobriyan (2):
Fix leaks on /proc/{*/sched,sched_debug,timer_list,timer_stats}
sched: remove binary sysctls from kernel.sched_domain
Avi Kivity (1):
sched: arch preempt notifier mechanism
Ingo Molnar (68):
sched: make cpu_clock() not use the rq clock
sched: remove cache_hot_time
sched: calc_delta_mine(): use fixed limit
sched: uninline calc_delta_mine()
sched: uninline inc/dec_nr_running()
sched: ->task_new cleanup
sched: move load-calculation functions
sched: add schedstat_set() API
sched: use schedstat_set() API
sched: reduce debug code
sched: batch sleeper bonus
sched: reorder update_cpu_load(rq) with the ->task_tick() call
sched: uninline rq_clock()
sched: schedule() speedup
sched: clean up delta_mine
sched: delta_exec accounting fix
sched: add [__]update_rq_clock(rq)
sched: eliminate rq_clock() use
sched: remove rq_clock()
sched: eliminate __rq_clock() use
sched: remove __rq_clock()
sched: remove 'now' use from assignments
sched: remove the 'u64 now' parameter from print_cfs_rq()
sched: remove the 'u64 now' parameter from update_curr()
sched: remove the 'u64 now' parameter from update_stats_wait_start()
sched: remove the 'u64 now' parameter from update_stats_enqueue()
sched: remove the 'u64 now' parameter from __update_stats_wait_end()
sched: remove the 'u64 now' parameter from update_stats_wait_end()
sched: remove the 'u64 now' parameter from update_stats_curr_start()
sched: remove the 'u64 now' parameter from update_stats_dequeue()
sched: remove the 'u64 now' parameter from update_stats_curr_end()
sched: remove the 'u64 now' parameter from __enqueue_sleeper()
sched: remove the 'u64 now' parameter from enqueue_sleeper()
sched: remove the 'u64 now' parameter from enqueue_entity()
sched: remove the 'u64 now' parameter from dequeue_entity()
sched: remove the 'u64 now' parameter from set_next_entity()
sched: remove the 'u64 now' parameter from pick_next_entity()
sched: remove the 'u64 now' parameter from put_prev_entity()
sched: remove the 'u64 now' parameter from update_curr_rt()
sched: remove the 'u64 now' parameter from ->enqueue_task()
sched: remove the 'u64 now' parameter from ->dequeue_task()
sched: remove the 'u64 now' parameter from ->pick_next_task()
sched: remove the 'u64 now' parameter from pick_next_task()
sched: remove the 'u64 now' parameter from ->put_prev_task()
sched: remove the 'u64 now' parameter from ->task_new()
sched: remove the 'u64 now' parameter from update_curr_load()
sched: remove the 'u64 now' parameter from inc_load()
sched: remove the 'u64 now' parameter from dec_load()
sched: remove the 'u64 now' parameter from inc_nr_running()
sched: remove the 'u64 now' parameter from dec_nr_running()
sched: remove the 'u64 now' parameter from enqueue_task()
sched: remove the 'u64 now' parameter from dequeue_task()
sched: remove the 'u64 now' parameter from deactivate_task()
sched: remove the 'u64 now' local variables
sched debug: remove the 'u64 now' parameter from print_task()/_rq()
sched: move the __update_rq_clock() call to scheduler_tick()
sched: remove __update_rq_clock() call from entity_tick()
sched: clean up set_curr_task_fair()
sched: optimize activate_task()
sched: optimize update_rq_clock() calls in the load-balancer
sched: make the multiplication table more accurate
sched: round a bit better
sched: fix update_stats_enqueue() reniced codepath
sched: refine negative nice level granularity
sched: improve rq-clock overflow logic
sched: fix typo in the FAIR_GROUP_SCHED branch
sched debug: dont print kernel address in /proc/sched_debug
sched: fix sleeper bonus
Josh Triplett (2):
sched: mark sysrq_sched_debug_show() static
sched: mark print_cfs_stats static
Nick Piggin (1):
sched: debug feature - make the sched-domains tree runtime-tweakable
Oleg Nesterov (1):
sched: run_rebalance_domains: s/SCHED_IDLE/CPU_IDLE/
Peter Williams (3):
sched: tidy up left over smpnice code
sched: simplify move_tasks()
sched: fix bug in balance_tasks()
Randy Dunlap (1):
sched: fix kernel-doc warnings
Satoru Takeuchi (1):
sched: remove unused rq->load_balance_class
Ulrich Drepper (1):
sched: clean up sched_getaffinity()
From: Ingo Molnar [5] [email blocked]
Subject: Re: [patch] CFS scheduler, -v20, for v2.6.22.5, v2.6.21.7, v2.6.20.16
Date: Thu, 23 Aug 2007 12:25:23 +0200
* Ingo Molnar [email blocked] wrote:
> By popular demand, here is release -v20 of the CFS scheduler. It is a
> full backport of the latest & greatest v2.6.23-rc3 CFS code to
> v2.6.22.5, v2.6.21.7 and v2.6.20.16. The patches can be downloaded
> from the usual place:
update: i missed a small SMP balancing fix so i've updated the patches
to -v20.1.
Ingo
From: Ingo Molnar [6] [email blocked]
To: Linus Torvalds [email blocked]
Cc: Andrew Morton [email blocked], linux-kernel@vger.kernel.org [7]
Subject: [git pull request] scheduler updates
Date: Thu, 23 Aug 2007 18:07:59 +0200
Linus, please pull the latest scheduler git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched.git
It includes six fixes: an s390 task-accounting fix from Christian
Borntraeger, sysctl directory permission fixes from Eric W. Biederman,
an SMT/MC balancing fix from Suresh Siddha (we under-balanced) and
another fix from Suresh for debugging tweak side-effect. Plus there's a
sched_clock() quality fix for CPUs that stop the TSC in idle (acked by
Len Brown) and a reniced-tasks fixlet.
the SMT/MC blancing fix has the highest risk - but since it causes
slightly more balancing (instead of less balancing, which is the more
risky action) it should be pretty safe. Key workloads still seem fine.
Tested on 32-bit and 64-bit x86 and it has passed 200+ make randconfig
build tests.
Ingo
---------------->
Christian Borntraeger (1):
sched: accounting regression since rc1
Eric W. Biederman (1):
sched: fix sysctl directory permissions
Ingo Molnar (2):
sched: sched_clock_idle_[sleep|wakeup]_event()
sched: tweak the sched_runtime_limit tunable
Suresh Siddha (2):
sched: fix broken SMT/MC optimizations
sched: skip updating rq's next_balance under null SD
arch/i386/kernel/tsc.c | 1
drivers/acpi/processor_idle.c | 32 +++++++++++++++----
fs/proc/array.c | 44 +++++++++++++++++----------
include/linux/sched.h | 5 +--
kernel/sched.c | 68 +++++++++++++++++++++++++++++++-----------
kernel/sched_debug.c | 3 +
6 files changed, 110 insertions(+), 43 deletions(-)
Related Links:
- Archive of above thread [8]
- KernelTrap interview with Ingo Molnar [9]