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| author | Ingo Molnar <mingo@kernel.org> | 2013-11-06 07:50:37 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-11-06 07:50:37 +0100 |
| commit | c90423d1de12fbeaf0c898e1db0e962de347302b (patch) | |
| tree | 8c7a32b37e74155324ae2b556fcc42718ccf29a3 /kernel/rcu | |
| parent | Merge branch 'core/rcu' into core/locking, to prepare the kernel/locking/ fil... (diff) | |
| parent | sched: Move completion code from core.c to completion.c (diff) | |
| download | linux-c90423d1de12fbeaf0c898e1db0e962de347302b.tar.xz linux-c90423d1de12fbeaf0c898e1db0e962de347302b.zip | |
Merge branch 'sched/core' into core/locking, to prepare the kernel/locking/ file move
Conflicts:
kernel/Makefile
There are conflicts in kernel/Makefile due to file moving in the
scheduler tree - resolve them.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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 8a2c81e86dda..4c06ddfea7cd 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) |