linux/kernel/sched
Frederic Weisbecker cab245d68c sched/cputime: Correctly handle task guest time on housekeepers
When a task runs on a housekeeper (a CPU running with the periodic tick
with neighbours running tickless), it doesn't account cputime using vtime
but relies on the tick. Such a task has its vtime_snap_whence value set
to VTIME_INACTIVE.

Readers won't handle that correctly though. As long as vtime is running
on some CPU, readers incorretly assume that vtime runs on all CPUs and
always compute the tickless cputime delta, which is only junk on
housekeepers.

So lets fix this with checking that the target runs on a vtime CPU through
the appropriate state check before computing the tickless delta.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1447948054-28668-5-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04 10:34:44 +01:00
..
auto_group.c sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE() 2015-05-08 12:11:32 +02:00
auto_group.h sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE() 2015-05-08 12:11:32 +02:00
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/fair: Make it possible to account fair load avg consistently 2015-12-04 10:34:42 +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: Unify dl_time_before() usage 2015-09-23 09:51:25 +02:00
cpudeadline.h sched/deadline: Unify dl_time_before() usage 2015-09-23 09:51:25 +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: Remove unnecessary definitions in cpupri.h 2014-11-16 10:58:59 +01:00
cputime.c sched/cputime: Correctly handle task guest time on housekeepers 2015-12-04 10:34:44 +01:00
deadline.c sched/core: Add missing lockdep_unpin() annotations 2015-10-23 12:02:10 +02:00
debug.c sched/fair: Provide runnable_load_avg back to cfs_rq 2015-08-03 12:24:31 +02:00
fair.c sched/fair: Make it possible to account fair load avg consistently 2015-12-04 10:34:42 +01:00
features.h sched/fair: Convert arch_scale_cpu_capacity() from weak function to #define 2015-09-13 09:52:55 +02:00
idle_task.c sched/fair: Remove empty idle enter and exit functions 2015-11-23 09:37:51 +01:00
idle.c sched, tracing: Stop/start critical timings around the idle=poll idle loop 2015-10-12 09:45:25 +02:00
loadavg.c sched: Move the loadavg code to a more obvious location 2015-05-08 12:04:12 +02:00
Makefile sched: Move the loadavg code to a more obvious location 2015-05-08 12:04:12 +02:00
rt.c sched/rt: Hide the push_irq_work_func() declaration 2015-11-23 09:25:08 +01:00
sched.h sched/fair: Make it possible to account fair load avg consistently 2015-12-04 10:34:42 +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/stat: Simplify the sched_info accounting dependency 2015-07-04 10:04:30 +02:00
stop_task.c sched: Make sched_class::set_cpus_allowed() unconditional 2015-08-12 12:06:09 +02:00
wait.c sched/wait: Fix signal handling in bit wait helpers 2015-12-04 10:10:15 +01:00