From 737223fbca3b1c91feb947c7f571b35749b743b6 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 5 Mar 2013 21:13:47 -0500 Subject: [PATCH] tracing: Consolidate buffer allocation code There's a bit of duplicate code in creating the trace buffers for the normal trace buffer and the max trace buffer among the instances and the main global_trace. This code can be consolidated and cleaned up a bit making the code cleaner and more readable as well as less duplication. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 130 +++++++++++++++++++++---------------------- 1 file changed, 63 insertions(+), 67 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bcc9460c2d65..57895d476509 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3171,6 +3171,7 @@ int tracer_init(struct tracer *t, struct trace_array *tr) static void set_buffer_entries(struct trace_buffer *buf, unsigned long val) { int cpu; + for_each_tracing_cpu(cpu) per_cpu_ptr(buf->data, cpu)->entries = val; } @@ -5267,12 +5268,70 @@ struct dentry *trace_instance_dir; static void init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer); -static int new_instance_create(const char *name) +static void init_trace_buffers(struct trace_array *tr, struct trace_buffer *buf) +{ + int cpu; + + for_each_tracing_cpu(cpu) { + memset(per_cpu_ptr(buf->data, cpu), 0, sizeof(struct trace_array_cpu)); + per_cpu_ptr(buf->data, cpu)->trace_cpu.cpu = cpu; + per_cpu_ptr(buf->data, cpu)->trace_cpu.tr = tr; + } +} + +static int allocate_trace_buffers(struct trace_array *tr, int size) { enum ring_buffer_flags rb_flags; + + rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; + + tr->trace_buffer.buffer = ring_buffer_alloc(size, rb_flags); + if (!tr->trace_buffer.buffer) + goto out_free; + + tr->trace_buffer.data = alloc_percpu(struct trace_array_cpu); + if (!tr->trace_buffer.data) + goto out_free; + + init_trace_buffers(tr, &tr->trace_buffer); + + /* Allocate the first page for all buffers */ + set_buffer_entries(&tr->trace_buffer, + ring_buffer_size(tr->trace_buffer.buffer, 0)); + +#ifdef CONFIG_TRACER_MAX_TRACE + + tr->max_buffer.buffer = ring_buffer_alloc(1, rb_flags); + if (!tr->max_buffer.buffer) + goto out_free; + + tr->max_buffer.data = alloc_percpu(struct trace_array_cpu); + if (!tr->max_buffer.data) + goto out_free; + + init_trace_buffers(tr, &tr->max_buffer); + + set_buffer_entries(&tr->max_buffer, 1); +#endif + return 0; + + out_free: + if (tr->trace_buffer.buffer) + ring_buffer_free(tr->trace_buffer.buffer); + free_percpu(tr->trace_buffer.data); + +#ifdef CONFIG_TRACER_MAX_TRACE + if (tr->max_buffer.buffer) + ring_buffer_free(tr->max_buffer.buffer); + free_percpu(tr->max_buffer.data); +#endif + return -ENOMEM; +} + +static int new_instance_create(const char *name) +{ struct trace_array *tr; int ret; - int i; mutex_lock(&trace_types_lock); @@ -5298,22 +5357,9 @@ static int new_instance_create(const char *name) INIT_LIST_HEAD(&tr->systems); INIT_LIST_HEAD(&tr->events); - rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; - - tr->trace_buffer.buffer = ring_buffer_alloc(trace_buf_size, rb_flags); - if (!tr->trace_buffer.buffer) - goto out_free_tr; - - tr->trace_buffer.data = alloc_percpu(struct trace_array_cpu); - if (!tr->trace_buffer.data) + if (allocate_trace_buffers(tr, trace_buf_size) < 0) goto out_free_tr; - for_each_tracing_cpu(i) { - memset(per_cpu_ptr(tr->trace_buffer.data, i), 0, sizeof(struct trace_array_cpu)); - per_cpu_ptr(tr->trace_buffer.data, i)->trace_cpu.cpu = i; - per_cpu_ptr(tr->trace_buffer.data, i)->trace_cpu.tr = tr; - } - /* Holder for file callbacks */ tr->trace_cpu.cpu = RING_BUFFER_ALL_CPUS; tr->trace_cpu.tr = tr; @@ -5736,8 +5782,6 @@ EXPORT_SYMBOL_GPL(ftrace_dump); __init static int tracer_alloc_buffers(void) { int ring_buf_size; - enum ring_buffer_flags rb_flags; - int i; int ret = -ENOMEM; @@ -5758,69 +5802,21 @@ __init static int tracer_alloc_buffers(void) else ring_buf_size = 1; - rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; - cpumask_copy(tracing_buffer_mask, cpu_possible_mask); cpumask_copy(tracing_cpumask, cpu_all_mask); raw_spin_lock_init(&global_trace.start_lock); /* TODO: make the number of buffers hot pluggable with CPUS */ - global_trace.trace_buffer.buffer = ring_buffer_alloc(ring_buf_size, rb_flags); - if (!global_trace.trace_buffer.buffer) { + if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); WARN_ON(1); goto out_free_cpumask; } - global_trace.trace_buffer.data = alloc_percpu(struct trace_array_cpu); - - if (!global_trace.trace_buffer.data) { - printk(KERN_ERR "tracer: failed to allocate percpu memory!\n"); - WARN_ON(1); - goto out_free_cpumask; - } - - for_each_tracing_cpu(i) { - memset(per_cpu_ptr(global_trace.trace_buffer.data, i), 0, - sizeof(struct trace_array_cpu)); - per_cpu_ptr(global_trace.trace_buffer.data, i)->trace_cpu.cpu = i; - per_cpu_ptr(global_trace.trace_buffer.data, i)->trace_cpu.tr = &global_trace; - } - if (global_trace.buffer_disabled) tracing_off(); -#ifdef CONFIG_TRACER_MAX_TRACE - global_trace.max_buffer.data = alloc_percpu(struct trace_array_cpu); - if (!global_trace.max_buffer.data) { - printk(KERN_ERR "tracer: failed to allocate percpu memory!\n"); - WARN_ON(1); - goto out_free_cpumask; - } - global_trace.max_buffer.buffer = ring_buffer_alloc(1, rb_flags); - if (!global_trace.max_buffer.buffer) { - printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); - WARN_ON(1); - ring_buffer_free(global_trace.trace_buffer.buffer); - goto out_free_cpumask; - } - - for_each_tracing_cpu(i) { - memset(per_cpu_ptr(global_trace.max_buffer.data, i), 0, - sizeof(struct trace_array_cpu)); - per_cpu_ptr(global_trace.max_buffer.data, i)->trace_cpu.cpu = i; - per_cpu_ptr(global_trace.max_buffer.data, i)->trace_cpu.tr = &global_trace; - } -#endif - - /* Allocate the first page for all buffers */ - set_buffer_entries(&global_trace.trace_buffer, - ring_buffer_size(global_trace.trace_buffer.buffer, 0)); -#ifdef CONFIG_TRACER_MAX_TRACE - set_buffer_entries(&global_trace.max_buffer, 1); -#endif - trace_init_cmdlines(); register_tracer(&nop_trace); -- 2.20.1