diff options
Diffstat (limited to 'kernel/rcu/tree.c')
| -rw-r--r-- | kernel/rcu/tree.c | 26 |
1 files changed, 11 insertions, 15 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 79c7fe978b17..b1fffa21b9e4 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1368,7 +1368,6 @@ static inline void panic_on_rcu_stall(void) static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum) { int cpu; - long delta; unsigned long flags; unsigned long gpa; unsigned long j; @@ -1381,18 +1380,6 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum) if (rcu_cpu_stall_suppress) return; - /* Only let one CPU complain about others per time interval. */ - - raw_spin_lock_irqsave_rcu_node(rnp, flags); - delta = jiffies - READ_ONCE(rsp->jiffies_stall); - if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) { - raw_spin_unlock_irqrestore_rcu_node(rnp, flags); - return; - } - WRITE_ONCE(rsp->jiffies_stall, - jiffies + 3 * rcu_jiffies_till_stall_check() + 3); - raw_spin_unlock_irqrestore_rcu_node(rnp, flags); - /* * OK, time to rat on our buddy... * See Documentation/RCU/stallwarn.txt for info on how to debug @@ -1441,6 +1428,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum) sched_show_task(current); } } + /* Rewrite if needed in case of slow consoles. */ + if (ULONG_CMP_GE(jiffies, READ_ONCE(rsp->jiffies_stall))) + WRITE_ONCE(rsp->jiffies_stall, + jiffies + 3 * rcu_jiffies_till_stall_check() + 3); rcu_check_gp_kthread_starvation(rsp); @@ -1485,6 +1476,7 @@ static void print_cpu_stall(struct rcu_state *rsp) rcu_dump_cpu_stacks(rsp); raw_spin_lock_irqsave_rcu_node(rnp, flags); + /* Rewrite if needed in case of slow consoles. */ if (ULONG_CMP_GE(jiffies, READ_ONCE(rsp->jiffies_stall))) WRITE_ONCE(rsp->jiffies_stall, jiffies + 3 * rcu_jiffies_till_stall_check() + 3); @@ -1508,6 +1500,7 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) unsigned long gpnum; unsigned long gps; unsigned long j; + unsigned long jn; unsigned long js; struct rcu_node *rnp; @@ -1546,14 +1539,17 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) ULONG_CMP_GE(gps, js)) return; /* No stall or GP completed since entering function. */ rnp = rdp->mynode; + jn = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; if (rcu_gp_in_progress(rsp) && - (READ_ONCE(rnp->qsmask) & rdp->grpmask)) { + (READ_ONCE(rnp->qsmask) & rdp->grpmask) && + cmpxchg(&rsp->jiffies_stall, js, jn) == js) { /* We haven't checked in, so go dump stack. */ print_cpu_stall(rsp); } else if (rcu_gp_in_progress(rsp) && - ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY)) { + ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY) && + cmpxchg(&rsp->jiffies_stall, js, jn) == js) { /* They had a few time units to dump stack, so complain. */ print_other_cpu_stall(rsp, gpnum); |