2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 13:13:57 +08:00
linux-next/kernel/sched
Steven Rostedt 4df1638cfa sched/deadline: Fix overflow to handle period==0 and deadline!=0
While debugging the crash with the bad nr_running accounting, I hit
another bug where, after running my sched deadline test, I was getting
failures to take a CPU offline. It was giving me a -EBUSY error.

Adding a bunch of trace_printk()s around, I found that the cpu
notifier that called sched_cpu_inactive() was returning a failure. The
overflow value was coming up negative?

Talking this over with Juri, the problem is that the total_bw update was
suppose to be made by dl_overflow() which, during my tests, seemed to
not be called. Adding more trace_printk()s, it wasn't that it wasn't
called, but it exited out right away with the check of new_bw being
equal to p->dl.dl_bw. The new_bw calculates the ratio between period and
runtime. The bug is that if you set a deadline, you do not need to set
a period if you plan on the period being equal to the deadline. That
is, if period is zero and deadline is not, then the system call should
set the period to be equal to the deadline. This is done elsewhere in
the code.

The fix is easy, check if period is set, and if it is not, then use the
deadline.

Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140219135335.7e74abd4@gandalf.local.home
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-02-21 21:27:09 +01:00
..
auto_group.c sched/autogroup: Fix race with task_groups list 2013-05-28 09:40:22 +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 sched/clock: Fixup early initialization 2014-01-23 14:48:36 +01:00
completion.c sched: Move completion code from core.c to completion.c 2013-11-06 07:49:19 +01:00
core.c sched/deadline: Fix overflow to handle period==0 and deadline!=0 2014-02-21 21:27:09 +01:00
cpuacct.c cgroup: replace cftype->read_seq_string() with cftype->seq_show() 2013-12-05 12:28:04 -05:00
cpuacct.h sched/cpuacct: Initialize root cpuacct earlier 2013-04-10 13:54:20 +02:00
cpudeadline.c sched/deadline: Fix sparse static warnings 2014-01-16 09:27:03 +01:00
cpudeadline.h sched/deadline: speed up SCHED_DEADLINE pushes with a push-heap 2014-01-13 13:46:46 +01:00
cpupri.c sched: Fix some kernel-doc warnings 2013-07-18 09:58:21 +02:00
cpupri.h sched: Move all scheduler bits into kernel/sched/ 2011-11-17 12:20:22 +01:00
cputime.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-05 12:36:46 -07:00
deadline.c sched/deadline: Fix bad accounting of nr_running 2014-02-21 21:27:09 +01:00
debug.c sched/clock, x86: Use a static_key for sched_clock_stable 2014-01-13 15:13:13 +01:00
fair.c Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-01-25 11:11:31 -08:00
features.h sched/numa: Resist moving tasks towards nodes with fewer hinting faults 2013-10-09 12:40:27 +02:00
idle_task.c sched/numa: Introduce migrate_swap() 2013-10-09 12:40:46 +02:00
Makefile sched/deadline: speed up SCHED_DEADLINE pushes with a push-heap 2014-01-13 13:46:46 +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/deadline: Add SCHED_DEADLINE SMP-related data structures & logic 2014-01-13 13:41:07 +01:00
sched.h sched: Reduce trigger_load_balance() parameters 2014-01-13 13:47:26 +01:00
stats.c fix a leak in /proc/schedstats 2013-04-29 15:41:45 -04:00
stats.h sched: Micro-optimize by dropping unnecessary task_rq() calls 2013-09-25 13:51:06 +02:00
stop_task.c sched/deadline: Add SCHED_DEADLINE structures & implementation 2014-01-13 13:41:06 +01:00
wait.c sched: Move wait code from core.c to wait.c 2013-11-06 07:49:18 +01:00