[tip: locking/core] locking/lockdep: Display irq_context names in /proc/lockdep_chains

From: tip-bot2 for Waiman Long
Date: Tue Feb 11 2020 - 07:48:45 EST


The following commit has been merged into the locking/core branch of tip:

Commit-ID: b9875e9882295749a14b31e16dd504ae904cf070
Gitweb: https://git.kernel.org/tip/b9875e9882295749a14b31e16dd504ae904cf070
Author: Waiman Long <longman@xxxxxxxxxx>
AuthorDate: Thu, 06 Feb 2020 10:24:04 -05:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 11 Feb 2020 13:10:48 +01:00

locking/lockdep: Display irq_context names in /proc/lockdep_chains

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@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200206152408.24165-3-longman@xxxxxxxxxx
---
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 231684c..c222438 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);