Steven Rostedt (Red Hat) ef477183d0 sched/debug: Add deadline scheduler bandwidth ratio to /proc/sched_debug ... Playing with SCHED_DEADLINE and cpusets, I found that I was unable to create new SCHED_DEADLINE tasks, with the error of EBUSY as if the bandwidth was already used up. I then realized there wa no way to see what bandwidth is used by the runqueues to debug the issue. By adding the dl_bw->bw and dl_bw->total_bw to the output of the deadline info in /proc/sched_debug, this allows us to see what bandwidth has been reserved and where a problem may exist. For example, before the issue we see the ratio of the bandwidth: # cat /proc/sys/kernel/sched_rt_runtime_us 950000 # cat /proc/sys/kernel/sched_rt_period_us 1000000 # grep dl /proc/sched_debug dl_rq[0]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[1]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[2]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[3]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[4]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[5]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[6]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 dl_rq[7]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 0 Note: (950000 / 1000000) << 20 == 996147 After I played with cpusets and hit the issue, the result is now: # grep dl /proc/sched_debug dl_rq[0]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[1]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 104857 dl_rq[2]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 104857 dl_rq[3]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : 104857 dl_rq[4]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[5]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[6]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 dl_rq[7]: .dl_nr_running : 0 .dl_bw->bw : 996147 .dl_bw->total_bw : -104857 This shows that there is definitely a problem as we should never have a negative total bandwidth. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160222212825.756849091@goodmis.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-02-29 09:53:07 +01:00
..
auto_group.c	sched/core: Move the sched_to_prio[] arrays out of line	2015-12-04 10:34:46 +01:00
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	Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2016-01-11 18:53:13 -08:00
completion.c	sched/completion: Serialize completion_done() with complete()	2015-02-18 14:27:40 +01:00
core.c	sched/debug: Move sched_domain_sysctl to debug.c	2016-02-29 09:53:06 +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	xen: features and fixes for 4.5-rc0	2016-01-12 13:05:36 -08:00
deadline.c	sched/deadline: Always calculate end of period on sched_yield()	2016-02-29 09:41:51 +01:00
debug.c	sched/debug: Add deadline scheduler bandwidth ratio to /proc/sched_debug	2016-02-29 09:53:07 +01:00
fair.c	sched/fair: Consolidate nohz CPU load update code	2016-02-29 09:53:04 +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	Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep'	2016-01-29 21:45:17 +01:00
loadavg.c	sched: Move the loadavg code to a more obvious location	2015-05-08 12:04:12 +02:00
Makefile	wait.[ch]: Introduce the simple waitqueue (swait) implementation	2016-02-25 11:27:16 +01:00
rt.c	sched/rt: Fix PI handling vs. sched_setscheduler()	2016-02-29 09:53:05 +01:00
sched.h	sched/debug: Move sched_domain_sysctl to debug.c	2016-02-29 09:53:06 +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/debug: Make schedstats a runtime tunable that is disabled by default	2016-02-09 11:54:23 +01:00
stop_task.c	sched: Make sched_class::set_cpus_allowed() unconditional	2015-08-12 12:06:09 +02:00
swait.c	wait.[ch]: Introduce the simple waitqueue (swait) implementation	2016-02-25 11:27:16 +01:00
wait.c	sched/wait: Fix the signal handling fix	2015-12-13 14:30:59 -08:00