[PATCH 04/21] tracing/filter: Use static allocation for filter predicates

Steven Rostedt
2011-09-22T22:14:55Z

[-- Attachment #1: 0004-tracing-filter-Use-static-allocation-for-filter-pred.patch --]
[-- Type: text/plain, Size: 2900 bytes --]

From: Jiri Olsa <jolsa@redhat.com>

Don't dynamically allocate filter_pred struct, use static memory.
This way we can get rid of the code managing the dynamic filter_pred
struct object.

The create_pred function integrates create_logical_pred function.
This way the static predicate memory is returned only from
one place.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1313072754-4620-2-git-send-email-jolsa@redhat.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 57 ++++++++++--------------------------
1 files changed, 16 insertions(+), 41 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 256764e..cb295a1 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -630,11 +630,7 @@ find_event_field(struct ftrace_event_call *call, char *name)

static void filter_free_pred(struct filter_pred *pred)
{
- if (!pred)
- return;
-
kfree(pred->field_name);
- kfree(pred);
}

static void filter_clear_pred(struct filter_pred *pred)
@@ -1302,39 +1298,30 @@ parse_operand:
return 0;
}

-static struct filter_pred *create_pred(int op, char *operand1, char *operand2)
+static struct filter_pred *create_pred(struct filter_parse_state *ps,
+ int op, char *operand1, char *operand2)
{
- struct filter_pred *pred;
+ static struct filter_pred pred;

- pred = kzalloc(sizeof(*pred), GFP_KERNEL);
- if (!pred)
- return NULL;
+ memset(&pred, 0, sizeof(pred));
+ pred.op = op;

- pred->field_name = kstrdup(operand1, GFP_KERNEL);
- if (!pred->field_name) {
- kfree(pred);
+ if (op == OP_AND || op == OP_OR)
+ return &pred;
+
+ if (!operand1 || !operand2) {
+ parse_error(ps, FILT_ERR_MISSING_FIELD, 0);
return NULL;
}

- strcpy(pred->regex.pattern, operand2);
- pred->regex.len = strlen(pred->regex.pattern);
-
- pred->op = op;
-
- return pred;
-}
-
-static struct filter_pred *create_logical_pred(int op)
-{
- struct filter_pred *pred;
-
- pred = kzalloc(sizeof(*pred), GFP_KERNEL);
- if (!pred)
+ pred.field_name = kstrdup(operand1, GFP_KERNEL);
+ if (!pred.field_name)
return NULL;

- pred->op = op;
+ strcpy(pred.regex.pattern, operand2);
+ pred.regex.len = strlen(pred.regex.pattern);

- return pred;
+ return &pred;
}

static int check_preds(struct filter_parse_state *ps)
@@ -1643,19 +1630,7 @@ static int replace_preds(struct ftrace_event_call *call,
goto fail;
}

- if (elt->op == OP_AND || elt->op == OP_OR) {
- pred = create_logical_pred(elt->op);
- goto add_pred;
- }
-
- if (!operand1 || !operand2) {
- parse_error(ps, FILT_ERR_MISSING_FIELD, 0);
- err = -EINVAL;
- goto fail;
- }
-
- pred = create_pred(elt->op, operand1, operand2);
-add_pred:
+ pred = create_pred(ps, elt->op, operand1, operand2);
if (!pred) {
err = -ENOMEM;
goto fail;
--
1.7.5.4