linux/kernel/sched
Brian Silverman 746db9443e sched: Fix RLIMIT_RTTIME when PI-boosting to RT
When non-realtime tasks get priority-inheritance boosted to a realtime
scheduling class, RLIMIT_RTTIME starts to apply to them. However, the
counter used for checking this (the same one used for SCHED_RR
timeslices) was not getting reset. This meant that tasks running with a
non-realtime scheduling class which are repeatedly boosted to a realtime
one, but never block while they are running realtime, eventually hit the
timeout without ever running for a time over the limit. This patch
resets the realtime timeslice counter when un-PI-boosting from an RT to
a non-RT scheduling class.

I have some test code with two threads and a shared PTHREAD_PRIO_INHERIT
mutex which induces priority boosting and spins while boosted that gets
killed by a SIGXCPU on non-fixed kernels but doesn't with this patch
applied. It happens much faster with a CONFIG_PREEMPT_RT kernel, and
does happen eventually with PREEMPT_VOLUNTARY kernels.

Signed-off-by: Brian Silverman <brian@peloton-tech.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: austin@peloton-tech.com
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1424305436-6716-1-git-send-email-brian@peloton-tech.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 10:47:55 +01:00
..
auto_group.c sched/autogroup: Fix failure to set cpu.rt_runtime_us 2015-02-18 16:17:20 +01:00
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/sched/clock.c: add another clock for use with the soft lockup watchdog 2015-02-12 18:54:13 -08:00
completion.c sched/completion: Serialize completion_done() with complete() 2015-02-18 14:27:40 +01:00
core.c sched: Fix RLIMIT_RTTIME when PI-boosting to RT 2015-03-23 10:47:55 +01:00
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: Remove cpu_active_mask from cpudl_find() 2015-02-04 07:52:29 +01:00
cpudeadline.h sched/deadline: Modify cpudl::free_cpus to reflect rd->online 2015-01-30 19:39:16 +01:00
cpupri.c Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
cpupri.h sched/cpupri: Remove unnecessary definitions in cpupri.h 2014-11-16 10:58:59 +01:00
cputime.c sched, time: Fix build error with 64 bit cputime_t on 32 bit systems 2014-10-03 05:46:55 +02:00
deadline.c sched/dl: Do update_rq_clock() in yield_task_dl() 2015-02-18 16:17:12 +01:00
debug.c sched/debug: Print rq->clock_task 2015-01-14 13:34:22 +01:00
fair.c Merge branch 'sched/urgent' into sched/core 2015-01-30 19:28:36 +01:00
features.h sched: Rename capacity related flags 2014-06-05 11:52:32 +02:00
idle_task.c sched: Provide update_curr callbacks for stop/idle scheduling classes 2014-11-23 14:14:40 -08:00
idle.c cpuidle / sleep: Use broadcast timer for states that stop local timer 2015-03-05 23:13:19 +01:00
Makefile ftrace: allow architectures to specify ftrace compile options 2015-01-29 09:19:19 +01:00
proc.c cpuidle: menu: Lookup CPU runqueues less 2014-08-06 21:17:45 +02:00
rt.c sched/rt: Reduce rq lock contention by eliminating locking of non-feasible target 2015-01-30 19:38:49 +01:00
sched.h sched: Make dl_task_time() use task_rq_lock() 2015-02-18 14:27:30 +01:00
stats.c sched: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
stats.h sched: Micro-optimize by dropping unnecessary task_rq() calls 2013-09-25 13:51:06 +02:00
stop_task.c sched: Provide update_curr callbacks for stop/idle scheduling classes 2014-11-23 14:14:40 -08:00
wait.c sched/wait: Fix a kthread race with wait_woken() 2014-11-04 07:17:44 +01:00