From 458faf0b88b19a46d51bb9760fa6e03a1bc6d97b Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Jul 2014 21:35:03 +0200 Subject: [PATCH] tracing: Kill the dead code in probe_sched_switch() and probe_sched_wakeup() After the previous patch it is clear that "tracer_enabled" can never be true, we can remove the "if (tracer_enabled)" code in probe_sched_switch() and probe_sched_wakeup(). Plus we can obviously remove tracer_enabled, ctx_trace, and sched_stopped as well. Link: http://lkml.kernel.org/p/20140723193503.GA30217@redhat.com Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt --- kernel/trace/trace_sched_switch.c | 40 --------------------------------------- 1 file changed, 40 deletions(-) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 3b60301..f7c7f4f1 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -14,12 +14,8 @@ #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); -static int sched_stopped; - void tracing_sched_switch_trace(struct trace_array *tr, @@ -52,29 +48,11 @@ tracing_sched_switch_trace(struct trace_array *tr, static void probe_sched_switch(void *ignore, struct task_struct *prev, struct task_struct *next) { - struct trace_array_cpu *data; - unsigned long flags; - int cpu; - int pc; - if (unlikely(!sched_ref)) return; tracing_record_cmdline(prev); tracing_record_cmdline(next); - - if (!tracer_enabled || sched_stopped) - return; - - pc = preempt_count(); - local_irq_save(flags); - cpu = raw_smp_processor_id(); - data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu); - - if (likely(!atomic_read(&data->disabled))) - tracing_sched_switch_trace(ctx_trace, prev, next, flags, pc); - - local_irq_restore(flags); } void @@ -108,28 +86,10 @@ tracing_sched_wakeup_trace(struct trace_array *tr, static void probe_sched_wakeup(void *ignore, struct task_struct *wakee, int success) { - struct trace_array_cpu *data; - unsigned long flags; - int cpu, pc; - if (unlikely(!sched_ref)) return; tracing_record_cmdline(current); - - if (!tracer_enabled || sched_stopped) - return; - - pc = preempt_count(); - local_irq_save(flags); - cpu = raw_smp_processor_id(); - data = per_cpu_ptr(ctx_trace->trace_buffer.data, cpu); - - if (likely(!atomic_read(&data->disabled))) - tracing_sched_wakeup_trace(ctx_trace, wakee, current, - flags, pc); - - local_irq_restore(flags); } static int tracing_sched_register(void) -- 2.7.4