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authorGuilherme G. Piccoli <gpiccoli@igalia.com>2023-03-14 21:00:58 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-04-08 22:45:38 +0200
commitf4708a82dc45fbf08bd3c68fc3eb32397e9121a1 (patch)
treed01dab55b1b2f387c2e383f8e658f6c057bab2f9 /kernel/notifier.c
parentkernel/hung_task.c: set some hung_task.c variables storage-class-specifier to... (diff)
downloadlinux-f4708a82dc45fbf08bd3c68fc3eb32397e9121a1.tar.xz
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notifiers: add tracepoints to the notifiers infrastructure
Currently there is no way to show the callback names for registered, unregistered or executed notifiers. This is very useful for debug purposes, hence add this functionality here in the form of notifiers' tracepoints, one per operation. [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/20230314200058.1326909-1-gpiccoli@igalia.com Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Michael Kelley <mikelley@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Xiaoming Ni <nixiaoming@huawei.com> Cc: Baoquan He <bhe@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com> Cc: Guilherme G. Piccoli <gpiccoli@igalia.com> Cc: Guilherme G. Piccoli <kernel@gpiccoli.net> Cc: Petr Mladek <pmladek@suse.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/notifier.c')
-rw-r--r--kernel/notifier.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/notifier.c b/kernel/notifier.c
index d353e4b5402d..b3ce28f39eb6 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -7,6 +7,9 @@
#include <linux/vmalloc.h>
#include <linux/reboot.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/notifier.h>
+
/*
* Notifier list for kernel code which wants to be called
* at shutdown. This is used to stop any idling DMA operations
@@ -37,6 +40,7 @@ static int notifier_chain_register(struct notifier_block **nl,
}
n->next = *nl;
rcu_assign_pointer(*nl, n);
+ trace_notifier_register((void *)n->notifier_call);
return 0;
}
@@ -46,6 +50,7 @@ static int notifier_chain_unregister(struct notifier_block **nl,
while ((*nl) != NULL) {
if ((*nl) == n) {
rcu_assign_pointer(*nl, n->next);
+ trace_notifier_unregister((void *)n->notifier_call);
return 0;
}
nl = &((*nl)->next);
@@ -84,6 +89,7 @@ static int notifier_call_chain(struct notifier_block **nl,
continue;
}
#endif
+ trace_notifier_run((void *)nb->notifier_call);
ret = nb->notifier_call(nb, val, v);
if (nr_calls)