From: "Steven Rostedt (Red Hat)" Add the "snapshot" file to the the multi-buffer instances. cd /sys/kernel/debug/tracing/instances mkdir foo ls foo buffer_size_kb buffer_total_size_kb events free_buffer set_event snapshot trace trace_clock trace_marker trace_options trace_pipe tracing_on cat foo/snapshot # tracer: nop # # # * Snapshot is freed * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1dec636..163743a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4273,9 +4273,9 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, local_irq_disable(); /* Now, we're going to swap */ if (iter->cpu_file == RING_BUFFER_ALL_CPUS) - update_max_tr(&global_trace, current, smp_processor_id()); + update_max_tr(tr, current, smp_processor_id()); else - update_max_tr_single(&global_trace, current, iter->cpu_file); + update_max_tr_single(tr, current, iter->cpu_file); local_irq_enable(); break; default: @@ -5497,6 +5497,11 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("tracing_on", 0644, d_tracer, tr, &rb_simple_fops); + +#ifdef CONFIG_TRACER_SNAPSHOT + trace_create_file("snapshot", 0644, d_tracer, + (void *)&tr->trace_cpu, &snapshot_fops); +#endif } static __init int tracer_init_debugfs(void) @@ -5538,11 +5543,6 @@ static __init int tracer_init_debugfs(void) &ftrace_update_tot_cnt, &tracing_dyn_info_fops); #endif -#ifdef CONFIG_TRACER_SNAPSHOT - trace_create_file("snapshot", 0644, d_tracer, - (void *)&global_trace.trace_cpu, &snapshot_fops); -#endif - create_trace_instances(d_tracer); create_trace_options_dir(&global_trace); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/