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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-04-15 10:12:40 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-05-10 11:08:34 -0700 |
| commit | c68de2097a8799549a3c3bf27cbfeea24a604284 (patch) | |
| tree | acf2e5cb6de06185002a7d22daa91d893068551b | |
| parent | 55ec936ff4e57cc626db336a7bf33b267390e9b4 (diff) | |
| download | linux-c68de2097a8799549a3c3bf27cbfeea24a604284.tar.gz linux-c68de2097a8799549a3c3bf27cbfeea24a604284.tar.bz2 linux-c68de2097a8799549a3c3bf27cbfeea24a604284.zip | |
rcu: disable CPU stall warnings upon panic
The current RCU CPU stall warnings remain enabled even after a panic
occurs, which some people have found to be a bit counterproductive.
This patch therefore uses a notifier to disable stall warnings once a
panic occurs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | kernel/rcutree.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 3623f8e10220..595fb83e9b7d 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -449,6 +449,8 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) #ifdef CONFIG_RCU_CPU_STALL_DETECTOR +int rcu_cpu_stall_panicking __read_mostly; + static void record_gp_stall_check_time(struct rcu_state *rsp) { rsp->gp_start = jiffies; @@ -526,6 +528,8 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) long delta; struct rcu_node *rnp; + if (rcu_cpu_stall_panicking) + return; delta = jiffies - rsp->jiffies_stall; rnp = rdp->mynode; if ((rnp->qsmask & rdp->grpmask) && delta >= 0) { @@ -540,6 +544,21 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) } } +static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr) +{ + rcu_cpu_stall_panicking = 1; + return NOTIFY_DONE; +} + +static struct notifier_block rcu_panic_block = { + .notifier_call = rcu_panic, +}; + +static void __init check_cpu_stall_init(void) +{ + atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block); +} + #else /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ static void record_gp_stall_check_time(struct rcu_state *rsp) @@ -550,6 +569,10 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) { } +static void __init check_cpu_stall_init(void) +{ +} + #endif /* #else #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ /* @@ -1934,6 +1957,7 @@ void __init rcu_init(void) cpu_notifier(rcu_cpu_notify, 0); for_each_online_cpu(cpu) rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu); + check_cpu_stall_init(); } #include "rcutree_plugin.h" |