This file can be reset, but the limit can not change in
size at runtime.
+config RING_BUFFER_RECORD_RECURSION
+ bool "Record functions that recurse in the ring buffer"
+ depends on FTRACE_RECORD_RECURSION
+ # default y, because it is coupled with FTRACE_RECORD_RECURSION
+ default y
+ help
+ The ring buffer has its own internal recursion. Although when
+ recursion happens it wont cause harm because of the protection,
+ but it does cause an unwanted overhead. Enabling this option will
+ place where recursion was detected into the ftrace "recursed_functions"
+ file.
+
+ This will add more overhead to cases that have recursion.
+
config GCOV_PROFILE_FTRACE
bool "Enable GCOV profiling on ftrace subsystem"
depends on GCOV_KERNEL
*
* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
*/
+#include <linux/trace_recursion.h>
#include <linux/trace_events.h>
#include <linux/ring_buffer.h>
#include <linux/trace_clock.h>
irq_work_queue(&cpu_buffer->irq_work.work);
}
+#ifdef CONFIG_RING_BUFFER_RECORD_RECURSION
+# define do_ring_buffer_record_recursion() \
+ do_ftrace_record_recursion(_THIS_IP_, _RET_IP_)
+#else
+# define do_ring_buffer_record_recursion() do { } while (0)
+#endif
+
/*
* The lock and unlock are done within a preempt disable section.
* The current_context per_cpu variable can only be modified
* been updated yet. In this case, use the TRANSITION bit.
*/
bit = RB_CTX_TRANSITION;
- if (val & (1 << (bit + cpu_buffer->nest)))
+ if (val & (1 << (bit + cpu_buffer->nest))) {
+ do_ring_buffer_record_recursion();
return 1;
+ }
}
val |= (1 << (bit + cpu_buffer->nest));