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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-12 01:20:12 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-12 01:20:12 (GMT) |
commit | 39cf275a1a18ba3c7eb9b986c5c9b35b57332798 (patch) | |
tree | 40b119ca9d2fbaf8128d3fa25f4c64669002b0c0 /kernel/rcu | |
parent | ad5d69899e52792671c1aa6c7360464c7edfe09c (diff) | |
parent | e5137b50a0640009fd63a3e65c14bc6e1be8796a (diff) | |
download | linux-fsl-qoriq-39cf275a1a18ba3c7eb9b986c5c9b35b57332798.tar.xz |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
"The main changes in this cycle are:
- (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik
van Riel, Peter Zijlstra et al. Yay!
- optimize preemption counter handling: merge the NEED_RESCHED flag
into the preempt_count variable, by Peter Zijlstra.
- wait.h fixes and code reorganization from Peter Zijlstra
- cfs_bandwidth fixes from Ben Segall
- SMP load-balancer cleanups from Peter Zijstra
- idle balancer improvements from Jason Low
- other fixes and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
stop_machine: Fix race between stop_two_cpus() and stop_cpus()
sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus
sched: Fix asymmetric scheduling for POWER7
sched: Move completion code from core.c to completion.c
sched: Move wait code from core.c to wait.c
sched: Move wait.c into kernel/sched/
sched/wait: Fix __wait_event_interruptible_lock_irq_timeout()
sched: Avoid throttle_cfs_rq() racing with period_timer stopping
sched: Guarantee new group-entities always have weight
sched: Fix hrtimer_cancel()/rq->lock deadlock
sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining
sched: Fix race on toggling cfs_bandwidth_used
sched: Remove extra put_online_cpus() inside sched_setaffinity()
sched/rt: Fix task_tick_rt() comment
sched/wait: Fix build breakage
sched/wait: Introduce prepare_to_wait_event()
sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too
sched: Remove get_online_cpus() usage
sched: Fix race in migrate_swap_stop()
...
Diffstat (limited to 'kernel/rcu')
-rw-r--r-- | kernel/rcu/tree.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8a2c81e..4c06ddf 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -916,6 +916,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp) force_quiescent_state(rsp); /* Kick them all. */ } +/* + * This function really isn't for public consumption, but RCU is special in + * that context switches can allow the state machine to make progress. + */ +extern void resched_cpu(int cpu); + static void print_cpu_stall(struct rcu_state *rsp) { int cpu; @@ -945,7 +951,14 @@ static void print_cpu_stall(struct rcu_state *rsp) 3 * rcu_jiffies_till_stall_check() + 3; raw_spin_unlock_irqrestore(&rnp->lock, flags); - set_need_resched(); /* kick ourselves to get things going. */ + /* + * Attempt to revive the RCU machinery by forcing a context switch. + * + * A context switch would normally allow the RCU state machine to make + * progress and it could be we're stuck in kernel space without context + * switches for an entirely unreasonable amount of time. + */ + resched_cpu(smp_processor_id()); } static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) |