diff options
author | Steven Rostedt <srostedt@redhat.com> | 2012-08-03 22:10:49 +0200 |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2013-03-15 05:34:44 +0100 |
commit | 277ba04461c2746cf935353474c0961161951b68 (patch) | |
tree | df2b8eb157c6725e606605f6acf40acbd4f13dd6 /kernel/trace/trace.h | |
parent | tracing: Make syscall events suitable for multiple buffers (diff) | |
download | linux-277ba04461c2746cf935353474c0961161951b68.tar.xz linux-277ba04461c2746cf935353474c0961161951b68.zip |
tracing: Add interface to allow multiple trace buffers
Add the interface ("instances" directory) to add multiple buffers
to ftrace. To create a new instance, simply do a mkdir in the
instances directory:
This will create a directory with the following:
# cd instances
# mkdir foo
# ls foo
buffer_size_kb free_buffer trace_clock trace_pipe
buffer_total_size_kb set_event trace_marker tracing_enabled
events/ trace trace_options tracing_on
Currently only events are able to be set, and there isn't a way
to delete a buffer when one is created (yet).
Note, the i_mutex lock is dropped from the parent "instances"
directory during the mkdir operation. As the "instances" directory
can not be renamed or deleted (created on boot), I do not see
any harm in dropping the lock. The creation of the sub directories
is protected by trace_types_lock mutex, which only lets one
instance get into the code path at a time. If two tasks try to
create or delete directories of the same name, only one will occur
and the other will fail with -EEXIST.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
-rw-r--r-- | kernel/trace/trace.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 68cad7a9e089..883fe0b62f0a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -175,6 +175,7 @@ struct tracer; struct trace_array { struct ring_buffer *buffer; struct list_head list; + char *name; int cpu; int buffer_disabled; struct trace_cpu trace_cpu; /* place holder */ @@ -999,6 +1000,7 @@ filter_check_discard(struct ftrace_event_call *call, void *rec, } extern void trace_event_enable_cmd_record(bool enable); +extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr); extern struct mutex event_mutex; extern struct list_head ftrace_events; |