From 4f712a4d04a4e49167118b41d8ea96df70a98985 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 11 Jan 2020 01:07:04 +0900 Subject: [PATCH] tracing/boot: Add instance node support Add instance node support to boot-time tracing. User can set some options and event nodes under instance node. - ftrace.instance.INSTANCE[...] Add new INSTANCE instance. Some options and event nodes are acceptable for instance node. Link: http://lkml.kernel.org/r/157867242413.17873.9814204526141500278.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_boot.c | 43 ++++++++++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 3054921b0877..f5db30d25b0b 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -20,7 +20,7 @@ extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr, unsigned long size, int cpu_id); static void __init -trace_boot_set_ftrace_options(struct trace_array *tr, struct xbc_node *node) +trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node) { struct xbc_node *anode; const char *p; @@ -242,6 +242,40 @@ trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node) } } +static void __init +trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node) +{ + trace_boot_set_instance_options(tr, node); + trace_boot_init_events(tr, node); + trace_boot_enable_events(tr, node); + trace_boot_enable_tracer(tr, node); +} + +static void __init +trace_boot_init_instances(struct xbc_node *node) +{ + struct xbc_node *inode; + struct trace_array *tr; + const char *p; + + node = xbc_node_find_child(node, "instance"); + if (!node) + return; + + xbc_node_for_each_child(node, inode) { + p = xbc_node_get_data(inode); + if (!p || *p == '\0') + continue; + + tr = trace_array_get_by_name(p); + if (IS_ERR(tr)) { + pr_err("Failed to get trace instance %s\n", p); + continue; + } + trace_boot_init_one_instance(tr, inode); + } +} + static int __init trace_boot_init(void) { struct xbc_node *trace_node; @@ -255,10 +289,9 @@ static int __init trace_boot_init(void) if (!tr) return 0; - trace_boot_set_ftrace_options(tr, trace_node); - trace_boot_init_events(tr, trace_node); - trace_boot_enable_events(tr, trace_node); - trace_boot_enable_tracer(tr, trace_node); + /* Global trace array is also one instance */ + trace_boot_init_one_instance(tr, trace_node); + trace_boot_init_instances(trace_node); return 0; }