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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-05-19 14:16:52 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-07-15 14:45:10 -0700 |
| commit | 319362c90f7af92d03714759bea5d2ba7c88e388 (patch) | |
| tree | b02526a5f71d213ad1647ec5503a7a4e968239ed /kernel/rcu | |
| parent | Linux 4.2-rc1 (diff) | |
| download | linux-dev-319362c90f7af92d03714759bea5d2ba7c88e388.tar.xz linux-dev-319362c90f7af92d03714759bea5d2ba7c88e388.zip | |
rcu: Provide more diagnostics for stalled GP kthread
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 10 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 6 |
2 files changed, 13 insertions, 3 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 65137bc28b2b..1c58cbd03922 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1178,9 +1178,11 @@ static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp) j = jiffies; gpa = READ_ONCE(rsp->gp_activity); if (j - gpa > 2 * HZ) - pr_err("%s kthread starved for %ld jiffies! g%lu c%lu f%#x\n", + pr_err("%s kthread starved for %ld jiffies! g%lu c%lu f%#x s%d ->state=%#lx\n", rsp->name, j - gpa, - rsp->gpnum, rsp->completed, rsp->gp_flags); + rsp->gpnum, rsp->completed, + rsp->gp_flags, rsp->gp_state, + rsp->gp_kthread ? rsp->gp_kthread->state : 0); } /* @@ -2041,6 +2043,7 @@ static int __noreturn rcu_gp_kthread(void *arg) wait_event_interruptible(rsp->gp_wq, READ_ONCE(rsp->gp_flags) & RCU_GP_FLAG_INIT); + rsp->gp_state = RCU_GP_DONE_GPS; /* Locking provides needed memory barrier. */ if (rcu_gp_init(rsp)) break; @@ -2073,6 +2076,7 @@ static int __noreturn rcu_gp_kthread(void *arg) (!READ_ONCE(rnp->qsmask) && !rcu_preempt_blocked_readers_cgp(rnp)), j); + rsp->gp_state = RCU_GP_DONE_FQS; /* Locking provides needed memory barriers. */ /* If grace period done, leave loop. */ if (!READ_ONCE(rnp->qsmask) && @@ -2110,7 +2114,9 @@ static int __noreturn rcu_gp_kthread(void *arg) } /* Handle grace-period end. */ + rsp->gp_state = RCU_GP_CLEANUP; rcu_gp_cleanup(rsp); + rsp->gp_state = RCU_GP_CLEANED; } } diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 4adb7ca0bf47..f1f4784f9107 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -527,7 +527,11 @@ struct rcu_state { /* Values for rcu_state structure's gp_flags field. */ #define RCU_GP_WAIT_INIT 0 /* Initial state. */ #define RCU_GP_WAIT_GPS 1 /* Wait for grace-period start. */ -#define RCU_GP_WAIT_FQS 2 /* Wait for force-quiescent-state time. */ +#define RCU_GP_DONE_GPS 2 /* Wait done for grace-period start. */ +#define RCU_GP_WAIT_FQS 3 /* Wait for force-quiescent-state time. */ +#define RCU_GP_DONE_FQS 4 /* Wait done for force-quiescent-state time. */ +#define RCU_GP_CLEANUP 5 /* Grace-period cleanup started. */ +#define RCU_GP_CLEANED 6 /* Grace-period cleanup complete. */ extern struct list_head rcu_struct_flavors; |