diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-08-17 17:05:59 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-10-09 14:25:17 -0700 |
| commit | 9b9500da81502738efa1b485a8835f174ff7be6d (patch) | |
| tree | a768a5aecca5e268ca4a90e9a312f87c729d4438 /kernel/rcu/tree_plugin.h | |
| parent | f79c3ad6189624c3de0ad5521610c9e22a1c33cf (diff) | |
rcu: Make RCU CPU stall warnings check for irq-disabled CPUs
One common question upon seeing an RCU CPU stall warning is "did
the stalled CPUs have interrupts disabled?" However, the current
stall warnings are silent on this point. This commit therefore
uses irq_work to check whether stalled CPUs still respond to IPIs,
and flags this state in the RCU CPU stall warning console messages.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index e012b9be777e..14977d0470d1 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1671,6 +1671,7 @@ static void print_cpu_stall_info_begin(void) */ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) { + unsigned long delta; char fast_no_hz[72]; struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); struct rcu_dynticks *rdtp = rdp->dynticks; @@ -1685,11 +1686,15 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) ticks_value = rsp->gpnum - rdp->gpnum; } print_cpu_stall_fast_no_hz(fast_no_hz, cpu); - pr_err("\t%d-%c%c%c: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n", + delta = rdp->mynode->gpnum - rdp->rcu_iw_gpnum; + pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n", cpu, "O."[!!cpu_online(cpu)], "o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)], "N."[!!(rdp->grpmask & rdp->mynode->qsmaskinitnext)], + !IS_ENABLED(CONFIG_IRQ_WORK) ? '?' : + rdp->rcu_iw_pending ? (int)min(delta, 9UL) + '0' : + "!."[!delta], ticks_value, ticks_title, rcu_dynticks_snap(rdtp) & 0xfff, rdtp->dynticks_nesting, rdtp->dynticks_nmi_nesting, |