Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1675164

[PATCH 28/32] tracing: Add hist trigger support for variable reference aliases

From Tom Zanussi <tom.zanussi@linux.intel.com>
Newsgroups linux.kernel
Subject [PATCH 28/32] tracing: Add hist trigger support for variable reference aliases
Date 2017-06-27 01:00 +0200
Message-ID <tWL98-8u4-39@gated-at.bofh.it> (permalink)
References <tWKZs-8nP-19@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Add support for alias=$somevar where alias can be used as
onmatch($alias).

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
 kernel/trace/trace_events_hist.c | 46 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 43 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 904a635..799b95e 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -225,6 +225,7 @@ enum hist_field_flags {
 	HIST_FIELD_FL_EXPR		= 16384,
 	HIST_FIELD_FL_VAR_REF		= 32768,
 	HIST_FIELD_FL_CPU		= 65536,
+	HIST_FIELD_FL_ALIAS		= 131072,
 };
 
 struct hist_trigger_attrs {
@@ -1414,7 +1415,8 @@ static const char *hist_field_name(struct hist_field *field,
 
 	if (field->field)
 		field_name = field->field->name;
-	else if (field->flags & HIST_FIELD_FL_LOG2)
+	else if (field->flags & HIST_FIELD_FL_LOG2 ||
+		 field->flags & HIST_FIELD_FL_ALIAS)
 		field_name = hist_field_name(field->operands[0], ++level);
 	else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
 		field_name = "$common_timestamp";
@@ -1819,7 +1821,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
 
 	hist_field->hist_data = hist_data;
 
-	if (flags & HIST_FIELD_FL_EXPR)
+	if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
 		goto out; /* caller will populate */
 
 	if (flags & HIST_FIELD_FL_VAR_REF) {
@@ -2013,6 +2015,34 @@ static struct hist_field *parse_var_ref(char *system, char *event_name,
 	return field;
 }
 
+static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
+				       struct hist_field *var_ref,
+				       char *var_name)
+{
+	struct hist_field *alias = NULL;
+	unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR |
+		HIST_FIELD_FL_VAR_ONLY;
+
+	alias = create_hist_field(hist_data, NULL, flags, var_name);
+	if (!alias)
+		return NULL;
+
+	alias->fn = var_ref->fn;
+	alias->operands[0] = var_ref;
+	alias->var.idx = var_ref->var.idx;
+	alias->var.hist_data = var_ref->hist_data;
+	alias->size = var_ref->size;
+	alias->is_signed = var_ref->is_signed;
+	alias->type = kstrdup(var_ref->type, GFP_KERNEL);
+	if (!alias->type) {
+		kfree(alias->type);
+		destroy_hist_field(alias, 0);
+		return NULL;
+	}
+
+	return alias;
+}
+
 struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
 			      struct trace_event_file *file, char *str,
 			      unsigned long *flags, char *var_name)
@@ -2036,6 +2066,13 @@ struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
 	if (hist_field) {
 		hist_data->var_refs[hist_data->n_var_refs] = hist_field;
 		hist_field->var_ref_idx = hist_data->n_var_refs++;
+		if (var_name) {
+			hist_field = create_alias(hist_data, hist_field, var_name);
+			if (!hist_field) {
+				ret = -ENOMEM;
+				goto out;
+			}
+		}
 		return hist_field;
 	}
 
@@ -4152,8 +4189,11 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
 		seq_puts(m, "$common_timestamp");
 	else if (hist_field->flags & HIST_FIELD_FL_CPU)
 		seq_puts(m, "cpu");
-	else if (field_name)
+	else if (field_name) {
+		if (hist_field->flags & HIST_FIELD_FL_ALIAS)
+			seq_putc(m, '$');
 		seq_printf(m, "%s", field_name);
+	}
 
 	if (hist_field->flags) {
 		const char *flags_str = get_hist_field_flags(hist_field);
-- 
1.9.3

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH 00/32]  tracing: Inter-event (e.g. latency) support Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 00:50 +0200
  [PATCH 17/32] tracing: Account for variables in named trigger compatibility Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 02/32] tracing: Reimplement log2 Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 10/32] tracing: Add NO_DISCARD event file flag Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 11/32] tracing: Add post-trigger flag to hist trigger command Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 19/32] tracing: Add variable reference handling to hist triggers Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 29/32] tracing: Add 'last error' error facility for hist triggers Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 04/32] ring-buffer: Redefine the unimplemented RINGBUF_TIME_TIME_STAMP Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
    Re: [PATCH 04/32] ring-buffer: Redefine the unimplemented RINGBUF_TIME_TIME_STAMP "Joel Fernandes (Google)" <joel.opensrc@gmail.com> - 2017-07-02 11:00 +0200
  [PATCH 06/32] tracing: Add ring buffer event param to hist field functions Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 16/32] tracing: Add variable support to hist triggers Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 20/32] tracing: Add support for dynamic tracepoints Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 24/32] tracing: Add 'onmax' hist trigger action support Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 03/32] ring-buffer: Add interface for setting absolute time stamps Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 13/32] tracing: Add per-element variable support to tracing_map Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 09/32] tracing: Make traceprobe parsing code reusable Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 28/32] tracing: Add hist trigger support for variable reference aliases Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 32/32] tracing: Add a clock attribute for hist triggers Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 25/32] tracing: Allow whitespace to surround hist trigger filter Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 05/32] tracing: Give event triggers access to ring_buffer_event Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 21/32] tracing: Add hist trigger action hook Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 07/32] tracing: Increase tracing map KEYS_MAX size Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 30/32] tracing: Add inter-event hist trigger Documentation Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 31/32] tracing: Make tracing_set_clock() non-static Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 22/32] tracing: Add support for 'synthetic' events Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 12/32] tracing: Add hist trigger timestamp support Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 18/32] tracing: Add simple expression support to hist triggers Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 08/32] tracing: Break out hist trigger assignment parsing Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 15/32] tracing: Add usecs modifier for hist trigger timestamps Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 23/32] tracing: Add 'onmatch' hist trigger action support Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 14/32] tracing: Add hist_data member to hist_field Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 26/32] tracing: Make duplicate count from tracing_map available Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 01/32] tracing: Add hist_field_name() accessor Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  [PATCH 27/32] tracing: Add cpu field for hist triggers Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-27 01:00 +0200
  Re: [PATCH 00/32]  tracing: Inter-event (e.g. latency) support Steven Rostedt <rostedt@goodmis.org> - 2017-06-27 17:10 +0200
  Re: [PATCH 00/32]  tracing: Inter-event (e.g. latency) support Masami Hiramatsu <mhiramat@kernel.org> - 2017-06-28 16:30 +0200
    Re: [PATCH 00/32]  tracing: Inter-event (e.g. latency) support Tom Zanussi <tom.zanussi@linux.intel.com> - 2017-06-28 21:20 +0200
  Re: [PATCH 00/32] tracing: Inter-event (e.g. latency) support "Joel Fernandes (Google)" <joel.opensrc@gmail.com> - 2017-07-01 09:10 +0200

csiph-web