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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt9
-rw-r--r--kernel/trace/trace.c11
2 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index fb8752b42ec8..e8ca4eabd152 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -7279,6 +7279,15 @@
See also "Event triggers" in Documentation/trace/events.rst
+ traceoff_after_boot
+ [FTRACE] Sometimes tracing is used to debug issues
+ during the boot process. Since the trace buffer has a
+ limited amount of storage, it may be prudent to
+ disable tracing after the boot is finished, otherwise
+ the critical information may be overwritten. With this
+ option, the main tracing buffer will be turned off at
+ the end of the boot process.
+
traceoff_on_warning
[FTRACE] enable this option to disable tracing when a
warning is hit. This turns off "tracing_on". Tracing can
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0e6d517e74e0..61458d8c3a61 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -87,6 +87,7 @@ void __init disable_tracing_selftest(const char *reason)
static struct trace_iterator *tracepoint_print_iter;
int tracepoint_printk;
static bool tracepoint_printk_stop_on_boot __initdata;
+static bool traceoff_after_boot __initdata;
static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key);
/* For tracers that don't implement custom flags */
@@ -330,6 +331,13 @@ static int __init set_tracepoint_printk_stop(char *str)
}
__setup("tp_printk_stop_on_boot", set_tracepoint_printk_stop);
+static int __init set_traceoff_after_boot(char *str)
+{
+ traceoff_after_boot = true;
+ return 1;
+}
+__setup("traceoff_after_boot", set_traceoff_after_boot);
+
unsigned long long ns2usecs(u64 nsec)
{
nsec += 500;
@@ -10704,6 +10712,9 @@ __init static int late_trace_init(void)
tracepoint_printk = 0;
}
+ if (traceoff_after_boot)
+ tracing_off();
+
tracing_set_default_clock();
clear_boot_tracer();
return 0;