linux/kernel/sched
Kirill Tkhai 163122b7fc sched/fair: Remove double_lock_balance() from load_balance()
Avoid double_rq_lock() and use TASK_ON_RQ_MIGRATING for
load_balance(). The advantage is (obviously) not holding two
rq->lock's at the same time and thereby increasing parallelism.

Further note that if there was no task to migrate we will not
have acquired the second rq->lock at all.

The important point to note is that because we acquire dst->lock
immediately after releasing src->lock the potential wait time of
task_rq_lock() callers on TASK_ON_RQ_MIGRATING is not longer
than it would have been in the double rq lock scenario.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1408528109.23412.94.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-20 14:53:05 +02:00
..
auto_group.c sched: Change autogroup_move_group() to use for_each_thread() 2014-08-20 09:47:18 +02:00
auto_group.h Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled" 2012-12-11 10:23:45 +01:00
clock.c kernel: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:36:11 -07:00
completion.c sched: Move completion code from core.c to completion.c 2013-11-06 07:49:19 +01:00
core.c sched: Remove double_rq_lock() from __migrate_task() 2014-08-20 14:53:02 +02:00
cpuacct.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
cpuacct.h sched/cpuacct: Initialize root cpuacct earlier 2013-04-10 13:54:20 +02:00
cpudeadline.c sched/deadline: Replace NR_CPUS arrays 2014-05-22 10:21:28 +02:00
cpudeadline.h sched/deadline: Replace NR_CPUS arrays 2014-05-22 10:21:28 +02:00
cpupri.c Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
cpupri.h sched/cpupri: Replace NR_CPUS arrays 2014-05-22 10:21:29 +02:00
cputime.c sched: Change thread_group_cputime() to use for_each_thread() 2014-08-20 09:47:18 +02:00
deadline.c sched: Add wrapper for checking task_struct::on_rq 2014-08-20 14:52:59 +02:00
debug.c sched: s/do_each_thread/for_each_process_thread/ in debug.c 2014-08-20 09:47:17 +02:00
fair.c sched/fair: Remove double_lock_balance() from load_balance() 2014-08-20 14:53:05 +02:00
features.h sched: Rename capacity related flags 2014-06-05 11:52:32 +02:00
idle_task.c sched: Transform resched_task() into resched_curr() 2014-07-16 13:38:19 +02:00
idle.c sched/idle: Drop !! while calculating 'broadcast' 2014-07-05 11:17:31 +02:00
Makefile sched/idle: Move cpu/idle.c to sched/idle.c 2014-02-11 09:58:30 +01:00
proc.c sched: Change get_rq_runnable_load() to static and inline 2013-06-27 10:07:44 +02:00
rt.c sched: Add wrapper for checking task_struct::on_rq 2014-08-20 14:52:59 +02:00
sched.h sched: Teach scheduler to understand TASK_ON_RQ_MIGRATING state 2014-08-20 14:53:00 +02:00
stats.c kernel: audit/fix non-modular users of module_init in core code 2014-04-03 16:21:07 -07:00
stats.h sched: Micro-optimize by dropping unnecessary task_rq() calls 2013-09-25 13:51:06 +02:00
stop_task.c sched: Add wrapper for checking task_struct::on_rq 2014-08-20 14:52:59 +02:00
wait.c sched: Allow wait_on_bit_action() functions to support a timeout 2014-07-16 15:10:41 +02:00