[PATCH v2 2/4] tracing: Add enabling of events to boot instances
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STALE1347d
REVIEWED: 1 (0M)
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2023-02-07 17:30:53
Also in:
lkml
Subsystem:
documentation, the rest, tracing · Maintainers:
Jonathan Corbet, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Revision v2 of 2 in this series; 1 review trailer.
Revisions (2)
- v1 [diff vs current]
- v2 current
From: "Steven Rostedt (Google)" <rostedt@goodmis.org> Add the format of: trace_instance=foo,sched:sched_switch,irq_handler_entry,initcall That will create the "foo" instance and enable the sched_switch event (here were the "sched" system is explicitly specified), the irq_handler_entry event, and all events under the system initcall. Reviewed-by: Ross Zwisler <redacted> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> --- Documentation/admin-guide/kernel-parameters.txt | 14 ++++++++++++++ kernel/trace/trace.c | 4 ++++ kernel/trace/trace.h | 2 ++ kernel/trace/trace_events.c | 9 ++++----- 4 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9545da5ed849..40304dc3d319 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt@@ -6278,6 +6278,20 @@ /sys/kernel/tracing/instances + Events can be enabled at the time the instance is created + via: + + trace_instance=<name>,<system1>:<event1>,<system2>:<event2> + + Note, the "<system*>:" portion is optional if the event is + unique. + + trace_instance=foo,sched:sched_switch,irq_handler_entry,initcall + + will enable the "sched_switch" event (note, the "sched:" is optional, and + the same thing would happen if it was left off). The irq_handler_entry + event, and all events under the "initcall" system. + trace_options=[option-list] [FTRACE] Enable or disable tracer options at boot. The option-list is a comma delimited list of options
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 863716fcca49..5b16af9e7d30 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c@@ -10188,6 +10188,10 @@ __init static void enable_instances(void) } /* Allow user space to delete it */ trace_array_put(tr); + + while ((tok = strsep(&curr_str, ","))) { + early_enable_events(tr, tok, true); + } } }
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index d16929dd0f08..f10bf804dd2b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h@@ -1334,6 +1334,8 @@ DECLARE_PER_CPU(int, trace_buffered_event_cnt); void trace_buffered_event_disable(void); void trace_buffered_event_enable(void); +void early_enable_events(struct trace_array *tr, char *buf, bool disable_first); + static inline void __trace_event_discard_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index b07931ad97de..cf3fd74fa675 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c@@ -3750,10 +3750,9 @@ static __init int event_trace_memsetup(void) return 0; } -static __init void -early_enable_events(struct trace_array *tr, bool disable_first) +__init void +early_enable_events(struct trace_array *tr, char *buf, bool disable_first) { - char *buf = bootup_event_buf; char *token; int ret;
@@ -3806,7 +3805,7 @@ static __init int event_trace_enable(void) */ __trace_early_add_events(tr); - early_enable_events(tr, false); + early_enable_events(tr, bootup_event_buf, false); trace_printk_start_comm();
@@ -3834,7 +3833,7 @@ static __init int event_trace_enable_again(void) if (!tr) return -ENODEV; - early_enable_events(tr, true); + early_enable_events(tr, bootup_event_buf, true); return 0; }
--
2.39.1