From: Tom Zanussi <tom.zanussi@linux.intel.com>
To: rostedt@goodmis.org
Cc: tglx@linutronix.de, mhiramat@kernel.org, namhyung@kernel.org,
vedang.patel@intel.com, linux-kernel@vger.kernel.org,
linux-rt-users@vger.kernel.org,
Tom Zanussi <tom.zanussi@linux.intel.com>
Subject: [PATCH 13/32] tracing: Add per-element variable support to tracing_map
Date: Mon, 26 Jun 2017 17:49:14 -0500 [thread overview]
Message-ID: <17566f1f2870ef5124e33de56f08f1fd304a06e0.1498510759.git.tom.zanussi@linux.intel.com> (raw)
In-Reply-To: <cover.1498510759.git.tom.zanussi@linux.intel.com>
In-Reply-To: <cover.1498510759.git.tom.zanussi@linux.intel.com>
In order to allow information to be passed between trace events, add
support for per-element variables to tracing_map. This provides a
means for histograms to associate a value or values with an entry when
it's saved or updated, and retrieved by a subsequent event occurrences.
Variables can be set using tracing_map_set_var() and read using
tracing_map_read_var(). tracing_map_var_set() returns true or false
depending on whether or not the variable has been set or not, which is
important for event-matching applications.
tracing_map_read_var_once() reads the variable and resets it to the
'unset' state, implementing read-once variables, which are also
important for event-matching uses.
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
kernel/trace/tracing_map.c | 113 +++++++++++++++++++++++++++++++++++++++++++++
kernel/trace/tracing_map.h | 11 +++++
2 files changed, 124 insertions(+)
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 0a689bb..f987069 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -66,6 +66,73 @@ u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i)
return (u64)atomic64_read(&elt->fields[i].sum);
}
+/**
+ * tracing_map_set_var - Assign a tracing_map_elt's variable field
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ * @n: The value to assign
+ *
+ * Assign n to variable i associated with the specified tracing_map_elt
+ * instance. The index i is the index returned by the call to
+ * tracing_map_add_var() when the tracing map was set up.
+ */
+void tracing_map_set_var(struct tracing_map_elt *elt, unsigned int i, u64 n)
+{
+ atomic64_set(&elt->vars[i], n);
+ elt->var_set[i] = true;
+}
+
+/**
+ * tracing_map_var_set - Return whether or not a variable has been set
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ *
+ * Return true if the variable has been set, false otherwise. The
+ * index i is the index returned by the call to tracing_map_add_var()
+ * when the tracing map was set up.
+ */
+bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i)
+{
+ return elt->var_set[i];
+}
+
+/**
+ * tracing_map_read_var - Return the value of a tracing_map_elt's variable field
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ *
+ * Retrieve the value of the variable i associated with the specified
+ * tracing_map_elt instance. The index i is the index returned by the
+ * call to tracing_map_add_var() when the tracing map was set
+ * up.
+ *
+ * Return: The variable value associated with field i for elt.
+ */
+u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i)
+{
+ return (u64)atomic64_read(&elt->vars[i]);
+}
+
+/**
+ * tracing_map_read_var_once - Return and reset a tracing_map_elt's variable field
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ *
+ * Retrieve the value of the variable i associated with the specified
+ * tracing_map_elt instance, and reset the variable to the 'not set'
+ * state. The index i is the index returned by the call to
+ * tracing_map_add_var() when the tracing map was set up. The reset
+ * essentially makes the variable a read-once variable if it's only
+ * accessed using this function.
+ *
+ * Return: The variable value associated with field i for elt.
+ */
+u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i)
+{
+ elt->var_set[i] = false;
+ return (u64)atomic64_read(&elt->vars[i]);
+}
+
int tracing_map_cmp_string(void *val_a, void *val_b)
{
char *a = val_a;
@@ -171,6 +238,28 @@ int tracing_map_add_sum_field(struct tracing_map *map)
}
/**
+ * tracing_map_add_var - Add a field describing a tracing_map var
+ * @map: The tracing_map
+ *
+ * Add a var to the map and return the index identifying it in the map
+ * and associated tracing_map_elts. This is the index used for
+ * instance to update a var for a particular tracing_map_elt using
+ * tracing_map_update_var() or reading it via tracing_map_read_var().
+ *
+ * Return: The index identifying the var in the map and associated
+ * tracing_map_elts, or -EINVAL on error.
+ */
+int tracing_map_add_var(struct tracing_map *map)
+{
+ int ret = -EINVAL;
+
+ if (map->n_vars < TRACING_MAP_VARS_MAX)
+ ret = map->n_vars++;
+
+ return ret;
+}
+
+/**
* tracing_map_add_key_field - Add a field describing a tracing_map key
* @map: The tracing_map
* @offset: The offset within the key
@@ -277,6 +366,11 @@ static void tracing_map_elt_clear(struct tracing_map_elt *elt)
if (elt->fields[i].cmp_fn == tracing_map_cmp_atomic64)
atomic64_set(&elt->fields[i].sum, 0);
+ for (i = 0; i < elt->map->n_vars; i++) {
+ atomic64_set(&elt->vars[i], 0);
+ elt->var_set[i] = false;
+ }
+
if (elt->map->ops && elt->map->ops->elt_clear)
elt->map->ops->elt_clear(elt);
}
@@ -303,6 +397,8 @@ static void tracing_map_elt_free(struct tracing_map_elt *elt)
if (elt->map->ops && elt->map->ops->elt_free)
elt->map->ops->elt_free(elt);
kfree(elt->fields);
+ kfree(elt->vars);
+ kfree(elt->var_set);
kfree(elt->key);
kfree(elt);
}
@@ -330,6 +426,18 @@ static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map)
goto free;
}
+ elt->vars = kcalloc(map->n_vars, sizeof(*elt->vars), GFP_KERNEL);
+ if (!elt->vars) {
+ err = -ENOMEM;
+ goto free;
+ }
+
+ elt->var_set = kcalloc(map->n_vars, sizeof(*elt->var_set), GFP_KERNEL);
+ if (!elt->var_set) {
+ err = -ENOMEM;
+ goto free;
+ }
+
tracing_map_elt_init_fields(elt);
if (map->ops && map->ops->elt_alloc) {
@@ -833,6 +941,11 @@ static struct tracing_map_elt *copy_elt(struct tracing_map_elt *elt)
dup_elt->fields[i].cmp_fn = elt->fields[i].cmp_fn;
}
+ for (i = 0; i < elt->map->n_vars; i++) {
+ atomic64_set(&dup_elt->vars[i], atomic64_read(&elt->vars[i]));
+ dup_elt->var_set[i] = elt->var_set[i];
+ }
+
return dup_elt;
}
diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h
index f097511..303bc4f 100644
--- a/kernel/trace/tracing_map.h
+++ b/kernel/trace/tracing_map.h
@@ -9,6 +9,7 @@
#define TRACING_MAP_VALS_MAX 3
#define TRACING_MAP_FIELDS_MAX (TRACING_MAP_KEYS_MAX + \
TRACING_MAP_VALS_MAX)
+#define TRACING_MAP_VARS_MAX 16
#define TRACING_MAP_SORT_KEYS_MAX 2
typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b);
@@ -136,6 +137,8 @@ struct tracing_map_field {
struct tracing_map_elt {
struct tracing_map *map;
struct tracing_map_field *fields;
+ atomic64_t *vars;
+ bool *var_set;
void *key;
void *private_data;
};
@@ -191,6 +194,7 @@ struct tracing_map {
int key_idx[TRACING_MAP_KEYS_MAX];
unsigned int n_keys;
struct tracing_map_sort_key sort_key;
+ unsigned int n_vars;
atomic64_t hits;
atomic64_t drops;
};
@@ -247,6 +251,7 @@ struct tracing_map_ops {
extern int tracing_map_init(struct tracing_map *map);
extern int tracing_map_add_sum_field(struct tracing_map *map);
+extern int tracing_map_add_var(struct tracing_map *map);
extern int tracing_map_add_key_field(struct tracing_map *map,
unsigned int offset,
tracing_map_cmp_fn_t cmp_fn);
@@ -266,7 +271,13 @@ extern tracing_map_cmp_fn_t tracing_map_cmp_num(int field_size,
extern void tracing_map_update_sum(struct tracing_map_elt *elt,
unsigned int i, u64 n);
+extern void tracing_map_set_var(struct tracing_map_elt *elt,
+ unsigned int i, u64 n);
+extern bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i);
extern u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i);
+extern u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i);
+extern u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i);
+
extern void tracing_map_set_field_descr(struct tracing_map *map,
unsigned int i,
unsigned int key_offset,
--
1.9.3
next prev parent reply other threads:[~2017-06-26 22:56 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-26 22:49 [PATCH 00/32] tracing: Inter-event (e.g. latency) support Tom Zanussi
2017-06-26 22:49 ` [PATCH 01/32] tracing: Add hist_field_name() accessor Tom Zanussi
2017-07-13 6:49 ` Piotr Gregor
2017-07-13 14:41 ` Tom Zanussi
2017-07-14 2:19 ` Namhyung Kim
2017-06-26 22:49 ` [PATCH 02/32] tracing: Reimplement log2 Tom Zanussi
2017-07-14 2:33 ` Namhyung Kim
2017-07-14 16:13 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 03/32] ring-buffer: Add interface for setting absolute time stamps Tom Zanussi
2017-07-14 5:25 ` Namhyung Kim
2017-07-14 16:14 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 04/32] ring-buffer: Redefine the unimplemented RINGBUF_TIME_TIME_STAMP Tom Zanussi
2017-07-02 8:51 ` Joel Fernandes (Google)
2017-06-26 22:49 ` [PATCH 05/32] tracing: Give event triggers access to ring_buffer_event Tom Zanussi
2017-06-26 22:49 ` [PATCH 06/32] tracing: Add ring buffer event param to hist field functions Tom Zanussi
2017-06-26 22:49 ` [PATCH 07/32] tracing: Increase tracing map KEYS_MAX size Tom Zanussi
2017-06-26 22:49 ` [PATCH 08/32] tracing: Break out hist trigger assignment parsing Tom Zanussi
2017-06-26 22:49 ` [PATCH 09/32] tracing: Make traceprobe parsing code reusable Tom Zanussi
2017-06-26 22:49 ` [PATCH 10/32] tracing: Add NO_DISCARD event file flag Tom Zanussi
2017-06-26 22:49 ` [PATCH 11/32] tracing: Add post-trigger flag to hist trigger command Tom Zanussi
2017-06-26 22:49 ` [PATCH 12/32] tracing: Add hist trigger timestamp support Tom Zanussi
2017-07-17 6:00 ` Namhyung Kim
2017-07-17 16:57 ` Tom Zanussi
2017-06-26 22:49 ` Tom Zanussi [this message]
2017-06-26 22:49 ` [PATCH 14/32] tracing: Add hist_data member to hist_field Tom Zanussi
2017-06-26 22:49 ` [PATCH 15/32] tracing: Add usecs modifier for hist trigger timestamps Tom Zanussi
2017-06-26 22:49 ` [PATCH 16/32] tracing: Add variable support to hist triggers Tom Zanussi
2017-07-19 1:07 ` Namhyung Kim
2017-07-19 15:40 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 17/32] tracing: Account for variables in named trigger compatibility Tom Zanussi
2017-06-26 22:49 ` [PATCH 18/32] tracing: Add simple expression support to hist triggers Tom Zanussi
2017-07-21 2:02 ` Namhyung Kim
2017-07-21 16:29 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 19/32] tracing: Add variable reference handling " Tom Zanussi
2017-07-21 3:31 ` Namhyung Kim
2017-07-21 16:41 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 20/32] tracing: Add support for dynamic tracepoints Tom Zanussi
2017-06-26 22:49 ` [PATCH 21/32] tracing: Add hist trigger action hook Tom Zanussi
2017-06-26 22:49 ` [PATCH 22/32] tracing: Add support for 'synthetic' events Tom Zanussi
2017-07-23 12:00 ` Namhyung Kim
2017-07-24 16:11 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 23/32] tracing: Add 'onmatch' hist trigger action support Tom Zanussi
2017-07-23 15:12 ` Namhyung Kim
2017-07-24 16:17 ` Tom Zanussi
2017-07-26 2:40 ` Namhyung Kim
2017-07-26 16:38 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 24/32] tracing: Add 'onmax' " Tom Zanussi
2017-07-26 3:04 ` Namhyung Kim
2017-07-26 16:45 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 25/32] tracing: Allow whitespace to surround hist trigger filter Tom Zanussi
2017-06-26 22:49 ` [PATCH 26/32] tracing: Make duplicate count from tracing_map available Tom Zanussi
2017-06-26 22:49 ` [PATCH 27/32] tracing: Add cpu field for hist triggers Tom Zanussi
2017-06-26 22:49 ` [PATCH 28/32] tracing: Add hist trigger support for variable reference aliases Tom Zanussi
2017-06-26 22:49 ` [PATCH 29/32] tracing: Add 'last error' error facility for hist triggers Tom Zanussi
2017-07-26 4:39 ` Namhyung Kim
2017-07-26 16:47 ` Tom Zanussi
2017-06-26 22:49 ` [PATCH 30/32] tracing: Add inter-event hist trigger Documentation Tom Zanussi
2017-06-26 22:49 ` [PATCH 31/32] tracing: Make tracing_set_clock() non-static Tom Zanussi
2017-06-26 22:49 ` [PATCH 32/32] tracing: Add a clock attribute for hist triggers Tom Zanussi
2017-06-27 14:58 ` [PATCH 00/32] tracing: Inter-event (e.g. latency) support Steven Rostedt
2017-06-28 14:21 ` Masami Hiramatsu
2017-06-28 19:09 ` Tom Zanussi
2017-07-01 7:01 ` Joel Fernandes (Google)
2017-07-12 19:17 ` Tom Zanussi
2017-07-04 16:12 ` Sebastian Andrzej Siewior
2017-07-12 19:20 ` Tom Zanussi
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