diff options
| author | Luca Abeni <luca.abeni@santannapisa.it> | 2017-05-18 22:13:32 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-06-08 10:31:51 +0200 |
| commit | 4da3abcefe178c650033f371e94fa10e80bce167 (patch) | |
| tree | 12d6b708fa1911e1053f85a0b29aab5bd41767f2 /kernel/sched/core.c | |
| parent | c52f14d384628db0217a7a9080ab800d5ffb2d72 (diff) | |
sched/deadline: Do not reclaim the whole CPU bandwidth
Original GRUB tends to reclaim 100% of the CPU time... And this
allows a CPU hog to starve non-deadline tasks.
To address this issue, allow the scheduler to reclaim only a
specified fraction of CPU time, stored in the new "bw_ratio"
field of the dl runqueue structure.
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-6-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b68a1fa05244..7abd06400a98 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6759,6 +6759,16 @@ static int sched_dl_global_validate(void) return ret; } +void init_dl_rq_bw_ratio(struct dl_rq *dl_rq) +{ + if (global_rt_runtime() == RUNTIME_INF) { + dl_rq->bw_ratio = 1 << RATIO_SHIFT; + } else { + dl_rq->bw_ratio = to_ratio(global_rt_runtime(), + global_rt_period()) >> (BW_SHIFT - RATIO_SHIFT); + } +} + static void sched_dl_do_global(void) { u64 new_bw = -1; @@ -6784,6 +6794,7 @@ static void sched_dl_do_global(void) raw_spin_unlock_irqrestore(&dl_b->lock, flags); rcu_read_unlock_sched(); + init_dl_rq_bw_ratio(&cpu_rq(cpu)->dl); } } |