Add ftrace.instance.*.alloc_snapshot option.
This option has been described in Documentation/trace/boottime-trace.rst
but not implemented yet.
ftrace.[instance.INSTANCE.]alloc_snapshot
Allocate snapshot buffer.
The difference from kernel.alloc_snapshot is that the kernel.alloc_snapshot
will allocate the buffer only for the main instance, but this can allocate
buffer for any new instances.
Link: https://lkml.kernel.org/r/160234368948.400560.15313384470765915015.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
if (tracing_set_tracer(tr, p) < 0)
pr_err("Failed to set given tracer: %s\n", p);
}
+
+ /* Since tracer can free snapshot buffer, allocate snapshot here.*/
+ if (xbc_node_find_value(node, "alloc_snapshot", NULL)) {
+ if (tracing_alloc_snapshot_instance(tr) < 0)
+ pr_err("Failed to allocate snapshot buffer\n");
+ }
}
static void __init