kernel_optimize_test/kernel/sched
Mathieu Desnoyers a961e40917 membarrier: Provide register expedited private command
This introduces a "register private expedited" membarrier command which
allows eventual removal of important memory barrier constraints on the
scheduler fast-paths. It changes how the "private expedited" membarrier
command (new to 4.14) is used from user-space.

This new command allows processes to register their intent to use the
private expedited command.  This affects how the expedited private
command introduced in 4.14-rc is meant to be used, and should be merged
before 4.14 final.

Processes are now required to register before using
MEMBARRIER_CMD_PRIVATE_EXPEDITED, otherwise that command returns EPERM.

This fixes a problem that arose when designing requested extensions to
sys_membarrier() to allow JITs to efficiently flush old code from
instruction caches.  Several potential algorithms are much less painful
if the user register intent to use this functionality early on, for
example, before the process spawns the second thread.  Registering at
this time removes the need to interrupt each and every thread in that
process at the first expedited sys_membarrier() system call.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-19 22:13:40 -04:00
..
autogroup.c sched/autogroup: Fix error reporting printk text in autogroup_create() 2017-08-10 17:06:03 +02:00
autogroup.h sched/headers: Prepare for new header dependencies before moving code to <linux/sched/autogroup.h> 2017-03-02 08:42:28 +01:00
clock.c sched/clock: Fix early boot preempt assumption in __set_sched_clock_stable() 2017-05-24 09:10:00 +02:00
completion.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-04 11:52:29 -07:00
core.c sched/debug: Ignore TASK_IDLE for SysRq-W 2017-09-29 11:02:57 +02:00
cpuacct.c sched/cputime: Convert kcpustat to nsecs 2017-02-01 09:13:47 +01:00
cpuacct.h sched/cpuacct: Simplify the cpuacct code 2016-03-21 11:00:28 +01:00
cpudeadline.c sched/deadline: Change return value of cpudl_find() 2017-08-10 12:18:17 +02:00
cpudeadline.h sched/deadline: Split cpudl_set() into cpudl_set() and cpudl_clear() 2016-09-05 13:29:43 +02:00
cpufreq_schedutil.c Merge branch 'pm-cpufreq-sched' 2017-09-04 00:05:22 +02:00
cpufreq.c cpufreq / sched: Pass flags to cpufreq_update_util() 2016-08-16 22:14:55 +02:00
cpupri.c sched/cpupri: Don't re-initialize 'struct cpupri' 2017-08-10 12:18:14 +02:00
cpupri.h sched/cpupri: Remove unnecessary definitions in cpupri.h 2014-11-16 10:58:59 +01:00
cputime.c sched/cputime: Don't use smp_processor_id() in preemptible context 2017-07-14 10:27:15 +02:00
deadline.c sched/deadline: replace earliest dl and rq leftmost caching 2017-09-08 18:26:49 -07:00
debug.c sched/debug: Remove unused variable 2017-09-29 10:09:09 +02:00
fair.c sched/core: Ensure load_balance() respects the active_mask 2017-10-10 10:14:03 +02:00
features.h sched/core: Address more wake_affine() regressions 2017-10-10 10:14:03 +02:00
idle_task.c sched/core: Add wrappers for lockdep_(un)pin_lock() 2017-01-14 11:29:30 +01:00
idle.c PM / s2idle: Rename ->enter_freeze to ->enter_s2idle 2017-08-11 01:29:56 +02:00
loadavg.c sched/loadavg: Generalize "_idle" naming to "_nohz" 2017-06-22 11:30:01 +02:00
Makefile membarrier: Provide expedited private command 2017-08-17 07:28:05 -07:00
membarrier.c membarrier: Provide register expedited private command 2017-10-19 22:13:40 -04:00
rt.c sched: cpufreq: Allow remote cpufreq callbacks 2017-08-01 14:24:53 +02:00
sched-pelt.h sched/fair: Move the PELT constants into a generated header 2017-04-14 10:26:37 +02:00
sched.h Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-13 12:22:32 -07:00
stats.c sched: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
stats.h sched/headers: Move cputime functionality from <linux/sched.h> and <linux/cputime.h> into <linux/sched/cputime.h> 2017-03-03 01:45:22 +01:00
stop_task.c sched/core: Add wrappers for lockdep_(un)pin_lock() 2017-01-14 11:29:30 +01:00
swait.c sched/wait: Remove the lockless swait_active() check in swake_up*() 2017-08-10 12:28:53 +02:00
topology.c Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-13 12:22:32 -07:00
wait_bit.c sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
wait.c sched/wait: Introduce wakeup boomark in wake_up_page_bit 2017-09-14 09:56:18 -07:00