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

Groups > linux.kernel > #1344395 > unrolled thread

[PATCH v15 03/23] tracing: Add hist trigger support for multiple values ('vals=' param)

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH v15 03/23] tracing: Add hist trigger support for multiple values ('vals=' param) Tom Zanussi <tom.zanussi@linux.intel.com> - 2016-02-26 17:10 +0100
    Re: [PATCH v15 03/23] tracing: Add hist trigger support for  multiple values ('vals=' param) Steven Rostedt <rostedt@goodmis.org> - 2016-03-02 15:40 +0100

#1344395 — [PATCH v15 03/23] tracing: Add hist trigger support for multiple values ('vals=' param)

Allow users to specify trace event fields to use in aggregated sums
via a new 'vals=' keyword.  Before this addition, the only aggregated
sum supported was the implied value 'hitcount'.  With this addition,
'hitcount' is also supported as an explicit value field, as is any
numeric trace event field.

This expands the hist trigger syntax from this:

  # echo hist:keys=xxx [ if filter] > event/trigger

to this:

  # echo hist:keys=xxx:vals=yyy [ if filter] > event/trigger

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
---
 kernel/trace/trace.c             | 12 ++++---
 kernel/trace/trace_events_hist.c | 77 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 83 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7140e2e..86cd8e6 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3825,14 +3825,16 @@ static const char readme_msg[] =
 #ifdef CONFIG_HIST_TRIGGERS
 	"      hist trigger\t- If set, event hits are aggregated into a hash table\n"
 	"\t    Format: hist:keys=<field1>\n"
+	"\t            [:values=<field1[,field2,...]>]\n"
 	"\t            [:size=#entries]\n"
 	"\t            [if <filter>]\n\n"
 	"\t    When a matching event is hit, an entry is added to a hash\n"
-	"\t    table using the key named, and the value of a sum called\n"
-	"\t    'hitcount' is incremented.  Keys correspond to fields in the\n"
-	"\t    event's format description.  Keys can be any field.  The\n"
-	"\t    'size' parameter can be  used to specify more or fewer than\n"
-	"\t    the default 2048 entries for the hashtable size.\n\n"
+	"\t    table using the key(s) and value(s) named, and the value of a\n"
+	"\t    sum called 'hitcount' is incremented.  Keys and values\n"
+	"\t    correspond to fields in the event's format description.  Keys\n"
+	"\t    can be any field.  Values must correspond to numeric fields.\n"
+	"\t    The 'size' parameter can be  used to specify more or fewer\n"
+	"\t    than the default 2048 entries for the hashtable size.\n\n"
 	"\t    Reading the 'hist' file for the event will dump the hash\n"
 	"\t    table in its entirety to stdout."
 #endif
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6ac881f..55e363d 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -84,6 +84,7 @@ enum hist_field_flags {
 
 struct hist_trigger_attrs {
 	char		*keys_str;
+	char		*vals_str;
 	unsigned int	map_bits;
 };
 
@@ -165,6 +166,7 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
 		return;
 
 	kfree(attrs->keys_str);
+	kfree(attrs->vals_str);
 	kfree(attrs);
 }
 
@@ -183,6 +185,10 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
 		if ((strncmp(str, "key=", strlen("key=")) == 0) ||
 		    (strncmp(str, "keys=", strlen("keys=")) == 0))
 			attrs->keys_str = kstrdup(str, GFP_KERNEL);
+		else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
+			 (strncmp(str, "vals=", strlen("vals=")) == 0) ||
+			 (strncmp(str, "values=", strlen("values=")) == 0))
+			attrs->vals_str = kstrdup(str, GFP_KERNEL);
 		else if (strncmp(str, "size=", strlen("size=")) == 0) {
 			int map_bits = parse_map_size(str);
 
@@ -274,13 +280,68 @@ static int create_hitcount_val(struct hist_trigger_data *hist_data)
 	return 0;
 }
 
+static int create_val_field(struct hist_trigger_data *hist_data,
+			    unsigned int val_idx,
+			    struct trace_event_file *file,
+			    char *field_str)
+{
+	struct ftrace_event_field *field = NULL;
+	unsigned long flags = 0;
+	int ret = 0;
+
+	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
+		return -EINVAL;
+	field = trace_find_event_field(file->event_call, field_str);
+	if (!field) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	hist_data->fields[val_idx] = create_hist_field(field, flags);
+	if (!hist_data->fields[val_idx]) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	if (WARN_ON(++hist_data->n_vals > TRACING_MAP_VALS_MAX))
+		ret = -EINVAL;
+ out:
+	return ret;
+}
+
 static int create_val_fields(struct hist_trigger_data *hist_data,
 			     struct trace_event_file *file)
 {
+	char *fields_str, *field_str;
+	unsigned int i, j;
 	int ret;
 
 	ret = create_hitcount_val(hist_data);
+	if (ret)
+		goto out;
+
+	fields_str = hist_data->attrs->vals_str;
+	if (!fields_str)
+		goto out;
+
+	strsep(&fields_str, "=");
+	if (!fields_str)
+		goto out;
 
+	for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
+		     j < TRACING_MAP_VALS_MAX; i++) {
+		field_str = strsep(&fields_str, ",");
+		if (!field_str)
+			break;
+		if (strcmp(field_str, "hitcount") == 0)
+			continue;
+		ret = create_val_field(hist_data, j++, file, field_str);
+		if (ret)
+			goto out;
+	}
+	if (fields_str && (strcmp(fields_str, "hitcount") != 0))
+		ret = -EINVAL;
+ out:
 	return ret;
 }
 
@@ -548,6 +609,12 @@ hist_trigger_entry_print(struct seq_file *m,
 	seq_printf(m, " hitcount: %10llu",
 		   tracing_map_read_sum(elt, HITCOUNT_IDX));
 
+	for (i = 1; i < hist_data->n_vals; i++) {
+		seq_printf(m, "  %s: %10llu",
+			   hist_data->fields[i]->field->name,
+			   tracing_map_read_sum(elt, i));
+	}
+
 	seq_puts(m, "\n");
 }
 
@@ -655,7 +722,15 @@ static int event_hist_trigger_print(struct seq_file *m,
 	}
 
 	seq_puts(m, ":vals=");
-	seq_puts(m, "hitcount");
+
+	for_each_hist_val_field(i, hist_data) {
+		if (i == HITCOUNT_IDX)
+			seq_puts(m, "hitcount");
+		else {
+			seq_puts(m, ",");
+			hist_field_print(m, hist_data->fields[i]);
+		}
+	}
 
 	seq_puts(m, ":sort=");
 	seq_puts(m, "hitcount");
-- 
1.9.3

[toc] | [next] | [standalone]

#1348095 — Re: [PATCH v15 03/23] tracing: Add hist trigger support for multiple values ('vals=' param)

On Fri, 26 Feb 2016 10:01:06 -0600
Tom Zanussi <tom.zanussi@linux.intel.com> wrote:

> +static int create_val_field(struct hist_trigger_data *hist_data,
> +			    unsigned int val_idx,
> +			    struct trace_event_file *file,
> +			    char *field_str)
> +{
> +	struct ftrace_event_field *field = NULL;
> +	unsigned long flags = 0;
> +	int ret = 0;
> +
> +	if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
> +		return -EINVAL;
> +	field = trace_find_event_field(file->event_call, field_str);
> +	if (!field) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	hist_data->fields[val_idx] = create_hist_field(field, flags);
> +	if (!hist_data->fields[val_idx]) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	if (WARN_ON(++hist_data->n_vals > TRACING_MAP_VALS_MAX))
> +		ret = -EINVAL;

Again, move the increment out of the WARN_ON().

> + out:
> +	return ret;
> +}
> +

-- Steve

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web