diff options
| author | Miquel Raynal <miquel.raynal@bootlin.com> | 2019-11-17 18:34:01 +0100 |
|---|---|---|
| committer | Miquel Raynal <miquel.raynal@bootlin.com> | 2019-11-17 18:34:01 +0100 |
| commit | 8389a7b909f252e74ea92b2794de8d660cfee96e (patch) | |
| tree | a947f3080e953e4a44417389b3f2b69d4817be2e /kernel/sched/fair.c | |
| parent | ad39b5a1ed68032292794b41a5f9e41ea69f8052 (diff) | |
| parent | 83cba933a6db1dd4d7ac85170f99461fbc339eff (diff) | |
Merge tag 'spi-nor/for-5.5' into mtd/next
SPI NOR core changes:
- introduce 'struct spi_nor_controller_ops',
- clean the Register Operations methods,
- use dev_dbg insted of dev_err for low level info,
- fix retlen handling in sst_write(),
- fix silent truncations in spi_nor_read and spi_nor_read_raw(),
- fix the clearing of QE bit on lock()/unlock(),
- rework the disabling of the block write protection,
- rework the Quad Enable methods,
- make sure nor->spimem and nor->controller_ops are mutually exclusive,
- set default Quad Enable method for ISSI flashes,
- add support for few flashes.
SPI NOR controller drivers changes:
- intel-spi:
- support chips without software sequencer,
- add support for Intel Cannon Lake and Intel Comet Lake-H flashes.
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 83ab35e2374f..682a754ea3e1 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4926,20 +4926,28 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) if (++count > 3) { u64 new, old = ktime_to_ns(cfs_b->period); - new = (old * 147) / 128; /* ~115% */ - new = min(new, max_cfs_quota_period); - - cfs_b->period = ns_to_ktime(new); - - /* since max is 1s, this is limited to 1e9^2, which fits in u64 */ - cfs_b->quota *= new; - cfs_b->quota = div64_u64(cfs_b->quota, old); - - pr_warn_ratelimited( - "cfs_period_timer[cpu%d]: period too short, scaling up (new cfs_period_us %lld, cfs_quota_us = %lld)\n", - smp_processor_id(), - div_u64(new, NSEC_PER_USEC), - div_u64(cfs_b->quota, NSEC_PER_USEC)); + /* + * Grow period by a factor of 2 to avoid losing precision. + * Precision loss in the quota/period ratio can cause __cfs_schedulable + * to fail. + */ + new = old * 2; + if (new < max_cfs_quota_period) { + cfs_b->period = ns_to_ktime(new); + cfs_b->quota *= 2; + + pr_warn_ratelimited( + "cfs_period_timer[cpu%d]: period too short, scaling up (new cfs_period_us = %lld, cfs_quota_us = %lld)\n", + smp_processor_id(), + div_u64(new, NSEC_PER_USEC), + div_u64(cfs_b->quota, NSEC_PER_USEC)); + } else { + pr_warn_ratelimited( + "cfs_period_timer[cpu%d]: period too short, but cannot scale up without losing precision (cfs_period_us = %lld, cfs_quota_us = %lld)\n", + smp_processor_id(), + div_u64(old, NSEC_PER_USEC), + div_u64(cfs_b->quota, NSEC_PER_USEC)); + } /* reset count so we don't come right back in here */ count = 0; |
