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authorMasami Hiramatsu <mhiramat@kernel.org>2021-08-10 11:07:36 +0900
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2021-08-16 11:37:21 -0400
commit17abd7c36c77c393fa65cde462059395d6437dba (patch)
tree86f595ce44fdcf384bffbf0a1ad7ce5b2b8936e9 /kernel/trace
parent8993665abcce793f00815b3504a486dce70cc2b9 (diff)
tracing/boot: Support multiple histograms for each event
Add multiple histograms support for each event. This allows user to set multiple histograms to an event. ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] { ... } The 'N' is a digit started string and it can be omitted for the default histogram. For example, multiple hist triggers example in the Documentation/trace/histogram.rst can be written as below; ftrace.event.net.netif_receive_skb.hist { 1 { keys = skbaddr.hex values = len filter = len < 0 } 2 { keys = skbaddr.hex values = len filter = len > 4096 } 3 { keys = skbaddr.hex values = len filter = len == 256 } 4 { keys = skbaddr.hex values = len } 5 { keys = len values = common_preempt_count } } Link: https://lkml.kernel.org/r/162856125628.203126.15846930277378572120.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_boot.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index f024f27b3602..1a2b270e9cda 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -324,7 +324,7 @@ trace_boot_hist_add_handlers(struct xbc_node *hnode, char **bufp,
/*
* Histogram boottime tracing syntax.
*
- * ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist {
+ * ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist[.N] {
* keys = <KEY>[,...]
* values = <VAL>[,...]
* sort = <SORT-KEY>[,...]
@@ -415,11 +415,37 @@ trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size)
return 0;
}
+
+static void __init
+trace_boot_init_histograms(struct trace_event_file *file,
+ struct xbc_node *hnode, char *buf, size_t size)
+{
+ struct xbc_node *node;
+ const char *p;
+
+ xbc_node_for_each_subkey(hnode, node) {
+ p = xbc_node_get_data(node);
+ if (!isdigit(p[0]))
+ continue;
+ /* All digit started node should be instances. */
+ if (trace_boot_compose_hist_cmd(node, buf, size) == 0) {
+ if (trigger_process_regex(file, buf) < 0)
+ pr_err("Failed to apply hist trigger: %s\n", buf);
+ }
+ }
+
+ if (xbc_node_find_child(hnode, "keys")) {
+ if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0)
+ if (trigger_process_regex(file, buf) < 0)
+ pr_err("Failed to apply hist trigger: %s\n", buf);
+ }
+}
#else
-static int __init
-trace_boot_compose_hist_cmd(struct xbc_node *hnode, char *buf, size_t size)
+static void __init
+trace_boot_init_histograms(struct trace_event_file *file,
+ struct xbc_node *hnode, char *buf, size_t size)
{
- return -EOPNOTSUPP;
+ /* do nothing */
}
#endif
@@ -465,11 +491,8 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
pr_err("Failed to apply an action: %s\n", buf);
}
anode = xbc_node_find_child(enode, "hist");
- if (anode &&
- trace_boot_compose_hist_cmd(anode, buf, ARRAY_SIZE(buf)) == 0) {
- if (trigger_process_regex(file, buf) < 0)
- pr_err("Failed to apply hist trigger: %s\n", buf);
- }
+ if (anode)
+ trace_boot_init_histograms(file, anode, buf, ARRAY_SIZE(buf));
} else if (xbc_node_find_value(enode, "actions", NULL))
pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n");

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