Messages in this thread Patch in this message | | | Date | Mon, 9 Feb 2009 19:15:35 -0200 | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH tip 1/1] tracing: Use a single trace_enabled variable |
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Impact: API change/cleanup
$ codiff kernel/trace/built-in.o.before kernel/trace/built-in.o kernel/trace/trace.c: tracing_is_enabled | -12 __find_next_entry | -5 2 functions changed, 17 bytes removed, diff: -17
kernel/trace/trace_sched_switch.c: tracing_sched_switch_assign_trace | -13 tracing_stop_sched_switch_record | -74 tracing_start_sched_switch_record | -30 3 functions changed, 117 bytes removed, diff: -117
kernel/trace/trace_sysprof.c: stack_trace_reset | -10 stack_trace_init | -10 2 functions changed, 20 bytes removed, diff: -20
kernel/trace/trace_irqsoff.c: irqsoff_tracer_start | -16 irqsoff_tracer_stop | -16 irqsoff_tracer_reset | -10 irqsoff_tracer_init | -19 4 functions changed, 61 bytes removed, diff: -61
kernel/trace/trace_sched_wakeup.c: wakeup_tracer_stop | -16 wakeup_tracer_start | -10 start_wakeup_tracer | -19 wakeup_tracer_reset | -10 4 functions changed, 55 bytes removed, diff: -55
kernel/trace/built-in.o: 15 functions changed, 270 bytes removed, diff: -270
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- kernel/trace/trace.c | 15 +------------- kernel/trace/trace.h | 3 +- kernel/trace/trace_irqsoff.c | 22 -------------------- kernel/trace/trace_sched_switch.c | 40 +------------------------------------ kernel/trace/trace_sched_wakeup.c | 26 ------------------------ kernel/trace/trace_sysprof.c | 5 +--- 6 files changed, 5 insertions(+), 106 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5b1e9a9..37bb6a9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -182,20 +182,7 @@ static struct trace_array max_tr; static DEFINE_PER_CPU(struct trace_array_cpu, max_data); /* tracer_enabled is used to toggle activation of a tracer */ -static int tracer_enabled = 1; - -/** - * tracing_is_enabled - return tracer_enabled status - * - * This function is used by other tracers to know the status - * of the tracer_enabled flag. Tracers may use this function - * to know if it should enable their features when starting - * up. See irqsoff tracer for an example (start_irqsoff_tracer). - */ -int tracing_is_enabled(void) -{ - return tracer_enabled; -} +int tracer_enabled __read_mostly; /* * trace_buf_size is the size in bytes that is allocated diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 7b0518a..faa4791 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -396,8 +396,9 @@ struct trace_iterator { cpumask_var_t started; }; +extern int tracer_enabled; + int tracer_init(struct tracer *t, struct trace_array *tr); -int tracing_is_enabled(void); void trace_wake_up(void); void tracing_reset(struct trace_array *tr, int cpu); void tracing_reset_online_cpus(struct trace_array *tr); diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index c6b442d..42364e8 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -19,7 +19,6 @@ #include "trace.h" static struct trace_array *irqsoff_trace __read_mostly; -static int tracer_enabled __read_mostly; static DEFINE_PER_CPU(int, tracing_cpu); @@ -356,15 +355,10 @@ void trace_preempt_off(unsigned long a0, unsigned long a1) static void start_irqsoff_tracer(struct trace_array *tr) { register_ftrace_function(&trace_ops); - if (tracing_is_enabled()) - tracer_enabled = 1; - else - tracer_enabled = 0; } static void stop_irqsoff_tracer(struct trace_array *tr) { - tracer_enabled = 0; unregister_ftrace_function(&trace_ops); } @@ -382,16 +376,6 @@ static void irqsoff_tracer_reset(struct trace_array *tr) stop_irqsoff_tracer(tr); } -static void irqsoff_tracer_start(struct trace_array *tr) -{ - tracer_enabled = 1; -} - -static void irqsoff_tracer_stop(struct trace_array *tr) -{ - tracer_enabled = 0; -} - #ifdef CONFIG_IRQSOFF_TRACER static int irqsoff_tracer_init(struct trace_array *tr) { @@ -405,8 +389,6 @@ static struct tracer irqsoff_tracer __read_mostly = .name = "irqsoff", .init = irqsoff_tracer_init, .reset = irqsoff_tracer_reset, - .start = irqsoff_tracer_start, - .stop = irqsoff_tracer_stop, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_irqsoff, @@ -431,8 +413,6 @@ static struct tracer preemptoff_tracer __read_mostly = .name = "preemptoff", .init = preemptoff_tracer_init, .reset = irqsoff_tracer_reset, - .start = irqsoff_tracer_start, - .stop = irqsoff_tracer_stop, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptoff, @@ -459,8 +439,6 @@ static struct tracer preemptirqsoff_tracer __read_mostly = .name = "preemptirqsoff", .init = preemptirqsoff_tracer_init, .reset = irqsoff_tracer_reset, - .start = irqsoff_tracer_start, - .stop = irqsoff_tracer_stop, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_preemptirqsoff, diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 30e14fe..828a70b 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -15,7 +15,6 @@ #include "trace.h" static struct trace_array *ctx_trace; -static int __read_mostly tracer_enabled; static int sched_ref; static DEFINE_MUTEX(sched_register_mutex); @@ -151,43 +150,6 @@ void tracing_start_sched_switch_record(void) } tracing_start_sched_switch(); - - mutex_lock(&sched_register_mutex); - tracer_enabled++; - mutex_unlock(&sched_register_mutex); -} - -/** - * tracing_stop_sched_switch_record - start tracing context switches - * - * Turns off context switch tracing for a tracer. - */ -void tracing_stop_sched_switch_record(void) -{ - mutex_lock(&sched_register_mutex); - tracer_enabled--; - WARN_ON(tracer_enabled < 0); - mutex_unlock(&sched_register_mutex); - - tracing_stop_sched_switch(); -} - -/** - * tracing_sched_switch_assign_trace - assign a trace array for ctx switch - * @tr: trace array pointer to assign - * - * Some tracers might want to record the context switches in their - * trace. This function lets those tracers assign the trace array - * to use. - */ -void tracing_sched_switch_assign_trace(struct trace_array *tr) -{ - ctx_trace = tr; -} - -static void stop_sched_trace(struct trace_array *tr) -{ - tracing_stop_sched_switch_record(); } static int sched_switch_trace_init(struct trace_array *tr) @@ -200,7 +162,7 @@ static int sched_switch_trace_init(struct trace_array *tr) static void sched_switch_trace_reset(struct trace_array *tr) { if (sched_ref) - stop_sched_trace(tr); + tracing_stop_sched_switch(); } static void sched_switch_trace_start(struct trace_array *tr) diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 96d7164..c526a1b 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -20,7 +20,6 @@ #include "trace.h" static struct trace_array *wakeup_trace; -static int __read_mostly tracer_enabled; static struct task_struct *wakeup_task; static int wakeup_cpu; @@ -289,23 +288,7 @@ static void start_wakeup_tracer(struct trace_array *tr) } wakeup_reset(tr); - - /* - * Don't let the tracer_enabled = 1 show up before - * the wakeup_task is reset. This may be overkill since - * wakeup_reset does a spin_unlock after setting the - * wakeup_task to NULL, but I want to be safe. - * This is a slow path anyway. - */ - smp_wmb(); - register_ftrace_function(&trace_ops); - - if (tracing_is_enabled()) - tracer_enabled = 1; - else - tracer_enabled = 0; - return; fail_deprobe_wake_new: unregister_trace_sched_wakeup_new(probe_wakeup); @@ -315,7 +298,6 @@ fail_deprobe: static void stop_wakeup_tracer(struct trace_array *tr) { - tracer_enabled = 0; unregister_ftrace_function(&trace_ops); unregister_trace_sched_switch(probe_wakeup_sched_switch); unregister_trace_sched_wakeup_new(probe_wakeup); @@ -352,12 +334,6 @@ static void wakeup_tracer_reset(struct trace_array *tr) static void wakeup_tracer_start(struct trace_array *tr) { wakeup_reset(tr); - tracer_enabled = 1; -} - -static void wakeup_tracer_stop(struct trace_array *tr) -{ - tracer_enabled = 0; } static struct tracer wakeup_tracer __read_mostly = @@ -366,7 +342,6 @@ static struct tracer wakeup_tracer __read_mostly = .init = wakeup_tracer_init, .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, - .stop = wakeup_tracer_stop, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, @@ -379,7 +354,6 @@ static struct tracer wakeup_rt_tracer __read_mostly = .init = wakeup_rt_tracer_init, .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, - .stop = wakeup_tracer_stop, .print_max = 1, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_wakeup, diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 84ca9d8..5c986b4 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -18,8 +18,7 @@ #include "trace.h" -static struct trace_array *sysprof_trace; -static int __read_mostly tracer_enabled; +static struct trace_array *sysprof_trace; /* * 1 msec sample interval by default: @@ -230,7 +229,6 @@ static void stop_stack_trace(struct trace_array *tr) { mutex_lock(&sample_timer_lock); stop_stack_timers(); - tracer_enabled = 0; mutex_unlock(&sample_timer_lock); } @@ -240,7 +238,6 @@ static int stack_trace_init(struct trace_array *tr) mutex_lock(&sample_timer_lock); start_stack_timers(); - tracer_enabled = 1; mutex_unlock(&sample_timer_lock); return 0; } -- 1.6.0.6
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