[PATCH v2 6/6] locking/lockdep: Display irq_context names in /proc/lockdep_chains

Waiman Long
2019-12-16T15:15:57Z

Currently, the irq_context field of a lock chains displayed in
/proc/lockdep_chains is just a number. It is likely that many people
may not know what a non-zero number means. To make the information more
useful, print the actual irq names ("softirq" and "hardirq") instead.

Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/locking/lockdep_proc.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 125c65e20bff..7f08bb4e7037 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -128,6 +128,13 @@ static int lc_show(struct seq_file *m, void *v)
struct lock_chain *chain = v;
struct lock_class *class;
int i;
+ static const char * const irq_strs[] = {
+ [0] = "0",
+ [LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq",
+ [LOCK_CHAIN_SOFTIRQ_CONTEXT] = "softirq",
+ [LOCK_CHAIN_SOFTIRQ_CONTEXT|
+ LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq|softirq",
+ };

if (v == SEQ_START_TOKEN) {
if (nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)
@@ -136,7 +143,7 @@ static int lc_show(struct seq_file *m, void *v)
return 0;
}

- seq_printf(m, "irq_context: %d\n", chain->irq_context);
+ seq_printf(m, "irq_context: %s\n", irq_strs[chain->irq_context]);

for (i = 0; i < chain->depth; i++) {
class = lock_chain_get_class(chain, i);
--
2.18.1