From: Steven Rostedt <rostedt@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [for-next][PATCH 15/20] tracing: Use system_state in trace_printk_init_buffers()
Date: Sun, 08 Feb 2026 21:20:41 -0500 [thread overview]
Message-ID: <20260209022054.507484055@kernel.org> (raw)
In-Reply-To: 20260209022026.627895421@kernel.org
From: Steven Rostedt <rostedt@goodmis.org>
The function trace_printk_init_buffers() is used to expand tha
trace_printk buffers when trace_printk() is used within the kernel or in
modules. On kernel boot up, it holds off from starting the sched switch
cmdline recorder, but will start it immediately when it is added by a
module.
Currently it uses a trick to see if the global_trace buffer has been
allocated or not to know if it was called by module load or not. But this
is more of a hack, and can not be used when this code is moved out of
trace.c. Instead simply look at the system_state and if it is running then
it is know that it could only be called by module load.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20260208032450.660237094@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f4ae80564615..4066c33674e7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3243,10 +3243,9 @@ void trace_printk_init_buffers(void)
/*
* trace_printk_init_buffers() can be called by modules.
* If that happens, then we need to start cmdline recording
- * directly here. If the global_trace.buffer is already
- * allocated here, then this was called by module code.
+ * directly here.
*/
- if (global_trace.array_buffer.buffer)
+ if (system_state == SYSTEM_RUNNING)
tracing_start_cmdline_record();
}
EXPORT_SYMBOL_GPL(trace_printk_init_buffers);
--
2.51.0
next prev parent reply other threads:[~2026-02-09 2:20 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-09 2:20 [for-next][PATCH 00/20] tracing: Updates for v6.20 Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 01/20] tracing: Add kerneldoc to trace_event_buffer_reserve() Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 02/20] tracing: Rename `eval_map_wq` and allow other parts of tracing use it Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 03/20] blktrace: Make init_blk_tracer() asynchronous Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 04/20] tracing/kprobes: Skip setup_boot_kprobe_events() when no cmdline event Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 05/20] tracing: Have all triggers expect a file parameter Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 06/20] tracing: Move tracing_set_filter_buffering() into trace_events_hist.c Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 07/20] tracing: Clean up use of trace_create_maxlat_file() Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 08/20] tracing: Make tracing_disabled global for tracing system Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 09/20] tracing: Make tracing_selftest_running global to the tracing subsystem Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 10/20] tracing: Move __trace_buffer_{un}lock_*() functions to trace.h Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 11/20] tracing: Move ftrace_trace_stack() out of trace.c and into trace.h Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 12/20] tracing: Make printk_trace global for tracing system Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 13/20] tracing: Make tracing_update_buffers() take NULL for global_trace Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 14/20] tracing: Have trace_printk functions use flags instead of using global_trace Steven Rostedt
2026-02-09 2:20 ` Steven Rostedt [this message]
2026-02-09 2:20 ` [for-next][PATCH 16/20] tracing: Move trace_printk functions out of trace.c and into trace_printk.c Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 17/20] tracing: Move pid filtering into trace_pid.c Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 18/20] tracing: Rename trace_array field max_buffer to snapshot_buffer Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 19/20] tracing: Add tracer_uses_snapshot() helper to remove #ifdefs Steven Rostedt
2026-02-09 2:20 ` [for-next][PATCH 20/20] tracing: Better separate SNAPSHOT and MAX_TRACE options Steven Rostedt
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