linux.git/kernel/sched/rt.c, branch v3.18-rc2

Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2014-10-15T05:48:18+00:00

Pull percpu consistent-ops changes from Tejun Heo:
"Way back, before the current percpu allocator was implemented, static
and dynamic percpu memory areas were allocated and handled separately
and had their own accessors. The distinction has been gone for many
years now; however, the now duplicate two sets of accessors remained
with the pointer based ones - this_cpu_*() - evolving various other
operations over time. During the process, we also accumulated other
inconsistent operations.

This pull request contains Christoph's patches to clean up the
duplicate accessor situation. __get_cpu_var() uses are replaced with
with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

Unfortunately, the former sometimes is tricky thanks to C being a bit
messy with the distinction between lvalues and pointers, which led to
a rather ugly solution for cpumask_var_t involving the introduction of
this_cpu_cpumask_var_ptr().

This converts most of the uses but not all. Christoph will follow up
with the remaining conversions in this merge window and hopefully
remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
irqchip: Properly fetch the per cpu offset
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
Revert "powerpc: Replace __get_cpu_var uses"
percpu: Remove __this_cpu_ptr
clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
sparc: Replace __get_cpu_var uses
avr32: Replace __get_cpu_var with __this_cpu_write
blackfin: Replace __get_cpu_var uses
tile: Use this_cpu_ptr() for hardware counters
tile: Replace __get_cpu_var uses
powerpc: Replace __get_cpu_var uses
alpha: Replace __get_cpu_var
ia64: Replace __get_cpu_var uses
s390: cio driver &__get_cpu_var replacements
s390: Replace __get_cpu_var uses
mips: Replace __get_cpu_var uses
MIPS: Replace __get_cpu_var uses in FPU emulator.
arm: Replace __this_cpu_ptr with raw_cpu_ptr
...

sched/rt: Use resched_curr() in task_tick_rt()

2014-09-24T12:47:12+00:00

Some time ago PREEMPT_NEED_RESCHED was implemented,
so reschedule technics is a little more difficult now.

Signed-off-by: Kirill Tkhai 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/20140922183642.11015.66039.stgit@localhost
Signed-off-by: Ingo Molnar

sched/rt: Remove useless if from cleanup pick_next_task_rt()

2014-09-19T10:35:20+00:00

_pick_next_task_rt() never returns NULL.

Signed-off-by: Kirill Tkhai 
Signed-off-by: Peter Zijlstra (Intel) 
Link: http://lkml.kernel.org/r/1410529321.3569.26.camel@tkhai
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t

2014-08-28T12:58:57+00:00

__get_cpu_var can paper over differences in the definitions of
cpumask_var_t and either use the address of the cpumask variable
directly or perform a fetch of the address of the struct cpumask
allocated elsewhere. This is important particularly when using per cpu
cpumask_var_t declarations because in one case we have an offset into
a per cpu area to handle and in the other case we need to fetch a
pointer from the offset.

This patch introduces a new macro

this_cpu_cpumask_var_ptr()

that is defined where cpumask_var_t is defined and performs the proper
actions. All use cases where __get_cpu_var is used with cpumask_var_t
are converted to the use of this_cpu_cpumask_var_ptr().

Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

sched: Add wrapper for checking task_struct::on_rq

2014-08-20T12:52:59+00:00

Implement task_on_rq_queued() and use it everywhere instead of
on_rq check. No functional changes.

The only exception is we do not use the wrapper in
check_for_tasks(), because it requires to export
task_on_rq_queued() in global header files. Next patch in series
would return it back, so we do not twist it from here to there.

Signed-off-by: Kirill Tkhai 
Cc: Peter Zijlstra 
Cc: Paul Turner 
Cc: Oleg Nesterov 
Cc: Steven Rostedt 
Cc: Mike Galbraith 
Cc: Kirill Tkhai 
Cc: Tim Chen 
Cc: Nicolas Pitre 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/1408528052.23412.87.camel@tkhai
Signed-off-by: Ingo Molnar

sched: Transform resched_task() into resched_curr()

2014-07-16T11:38:19+00:00

We always use resched_task() with rq->curr argument.
It's not possible to reschedule any task but rq's current.

The patch introduces resched_curr(struct rq *) to
replace all of the repeating patterns. The main aim
is cleanup, but there is a little size profit too:

  (before)
	$ size kernel/sched/built-in.o
	   text	   data	    bss	    dec	    hex	filename
	155274	  16445	   7042	 178761	  2ba49	kernel/sched/built-in.o

	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	7411490	1178376	 991232	9581098	 92322a	vmlinux

  (after)
	$ size kernel/sched/built-in.o
	   text	   data	    bss	    dec	    hex	filename
	155130	  16445	   7042	 178617	  2b9b9	kernel/sched/built-in.o

	$ size vmlinux
	   text	   data	    bss	    dec	    hex	filename
	7411362	1178376	 991232	9580970	 9231aa	vmlinux

	I was choosing between resched_curr() and resched_rq(),
	and the first name looks better for me.

A little lie in Documentation/trace/ftrace.txt. I have not
actually collected the tracing again. With a hope the patch
won't make execution times much worse :)

Signed-off-by: Kirill Tkhai 
Signed-off-by: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Randy Dunlap 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/20140628200219.1778.18735.stgit@localhost
Signed-off-by: Ingo Molnar

sched/rt: Enqueue just unthrottled rt_rq back on the stack in __disable_runtime()

2014-07-05T09:17:44+00:00

Make rt_rq available for pick_next_task(). Otherwise, their tasks
stay prisoned long time till dead cpu becomes alive again.

Reviewed-by: Srikar Dronamraju 
Signed-off-by: Kirill Tkhai 
CC: Konstantin Khorenko 
CC: Ben Segall 
CC: Paul Turner 
CC: Mike Galbraith 
Cc: Linus Torvalds 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1403684388.3462.43.camel@tkhai
Signed-off-by: Ingo Molnar

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-06-13T02:42:15+00:00

Pull more scheduler updates from Ingo Molnar:
 "Second round of scheduler changes:
   - try-to-wakeup and IPI reduction speedups, from Andy Lutomirski
   - continued power scheduling cleanups and refactorings, from Nicolas
     Pitre
   - misc fixes and enhancements"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Delete extraneous extern for to_ratio()
  sched/idle: Optimize try-to-wake-up IPI
  sched/idle: Simplify wake_up_idle_cpu()
  sched/idle: Clear polling before descheduling the idle thread
  sched, trace: Add a tracepoint for IPI-less remote wakeups
  cpuidle: Set polling in poll_idle
  sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)
  sched: Rename capacity related flags
  sched: Final power vs. capacity cleanups
  sched: Remove remaining dubious usage of "power"
  sched: Let 'struct sched_group_power' care about CPU capacity
  sched/fair: Disambiguate existing/remaining "capacity" usage
  sched/fair: Change "has_capacity" to "has_free_capacity"
  sched/fair: Remove "power" from 'struct numa_stats'
  sched: Fix signedness bug in yield_to()
  sched/fair: Use time_after() in record_wakee()
  sched/balancing: Reduce the rate of needless idle load balancing
  sched/fair: Fix unlocked reads of some cfs_b->quota/period

sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)

2014-06-05T09:52:34+00:00

Variable "rt_rq" is used only in block "for_each_sched_rt_entity" so the
value assigned to it at the beginning of the update_curr_rt(...) gets
overwritten without ever being read. Remove redundant assignment and
move variable declaration to the block in which it is being used.

Signed-off-by: Giedrius Rekasius 
Signed-off-by: Peter Zijlstra 
Cc: kernel-janitors@vger.kernel.org
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1401027811-30066-1-git-send-email-giedrius.rekasius@gmail.com
Signed-off-by: Ingo Molnar

printk: Add printk_deferred_once

2014-06-04T23:54:17+00:00

Two of the three prink_deferred uses are really printk_once style
uses, so add a printk_deferred_once macro to simplify those call
sites.

Signed-off-by: John Stultz 
Reviewed-by: Steven Rostedt 
Reviewed-by: Jan Kara 
Cc: Peter Zijlstra 
Cc: Jiri Bohac 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds