/* * nop tracer * * Copyright (C) 2008 Steven Noonan <steven@uplinklabs.net> * */ #include <linux/module.h> #include <linux/fs.h> #include <linux/debugfs.h> #include <linux/ftrace.h> #include "trace.h" static struct trace_array *ctx_trace; static void start_nop_trace(struct trace_array *tr) { /* Nothing to do! */ } static void stop_nop_trace(struct trace_array *tr) { /* Nothing to do! */ } static void nop_trace_init(struct trace_array *tr) { int cpu; ctx_trace = tr; for_each_online_cpu(cpu) tracing_reset(tr, cpu); if (tr->ctrl) start_nop_trace(tr); } static void nop_trace_reset(struct trace_array *tr) { if (tr->ctrl) stop_nop_trace(tr); } static void nop_trace_ctrl_update(struct trace_array *tr) { /* When starting a new trace, reset the buffers */ if (tr->ctrl) start_nop_trace(tr); else stop_nop_trace(tr); } struct tracer nop_trace __read_mostly = { .name = "nop", .init = nop_trace_init, .reset = nop_trace_reset, .ctrl_update = nop_trace_ctrl_update, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_nop, #endif };