Re: [dpdk-dev] [EXT] [PATCH 6/8] trace: remove limitation on patterns number

[Sunil Kumar Kori <skori@marvell.com>]

>-----Original Message-----
>From: David Marchand <david.marchand@redhat.com>
>Sent: Monday, May 4, 2020 2:02 AM
>To: dev@dpdk.org
>Cc: thomas@monjalon.net; Jerin Jacob Kollanukkaran <jerinj@marvell.com>;
>Sunil Kumar Kori <skori@marvell.com>
>Subject: [EXT] [PATCH 6/8] trace: remove limitation on patterns number
>
>External Email
>
>----------------------------------------------------------------------
>There is nothing performance sensitive in this list, use dynamic allocations and
>remove the arbitrary limit on the number of trace patterns a user can pass.
>
>Signed-off-by: David Marchand <david.marchand@redhat.com>
>---
> lib/librte_eal/common/eal_common_trace.c      | 10 +++---
> .../common/eal_common_trace_utils.c           | 33 ++++++++-----------
> lib/librte_eal/common/eal_trace.h             |  8 ++---
> 3 files changed, 23 insertions(+), 28 deletions(-)
>
>diff --git a/lib/librte_eal/common/eal_common_trace.c
>b/lib/librte_eal/common/eal_common_trace.c
>index 5a365c61da..875553d7e5 100644
>--- a/lib/librte_eal/common/eal_common_trace.c
>+++ b/lib/librte_eal/common/eal_common_trace.c
>@@ -21,7 +21,7 @@ static RTE_DEFINE_PER_LCORE(char,
>ctf_field[TRACE_CTF_FIELD_SIZE]);  static RTE_DEFINE_PER_LCORE(int,
>ctf_count);
>
> static struct trace_point_head tp_list = STAILQ_HEAD_INITIALIZER(tp_list); -
>static struct trace trace;
>+static struct trace trace = { .args =
>+STAILQ_HEAD_INITIALIZER(trace.args), };
>
> struct trace *
> trace_obj_get(void)
>@@ -38,7 +38,7 @@ trace_list_head_get(void)  int
> eal_trace_init(void)
> {
>-	uint8_t i;
>+	struct trace_arg *arg;
>
> 	/* Trace memory should start with 8B aligned for natural alignment */
> 	RTE_BUILD_BUG_ON((offsetof(struct __rte_trace_header, mem) % 8)
>!= 0); @@ -49,7 +49,7 @@ eal_trace_init(void)
> 		goto fail;
> 	}
>
>-	if (trace.args.nb_args)
>+	if (!STAILQ_EMPTY(&trace.args))
> 		trace.status = true;
>
> 	if (!rte_trace_is_enabled())
>@@ -82,8 +82,8 @@ eal_trace_init(void)
> 		goto fail;
>
> 	/* Apply global configurations */
>-	for (i = 0; i < trace.args.nb_args; i++)
>-		trace_args_apply(trace.args.args[i]);
>+	STAILQ_FOREACH(arg, &trace.args, next)
>+		trace_args_apply(arg->val);
>
> 	rte_trace_mode_set(trace.mode);
>
>diff --git a/lib/librte_eal/common/eal_common_trace_utils.c
>b/lib/librte_eal/common/eal_common_trace_utils.c
>index 4077acf428..15384ce4f1 100644
>--- a/lib/librte_eal/common/eal_common_trace_utils.c
>+++ b/lib/librte_eal/common/eal_common_trace_utils.c
>@@ -138,25 +138,20 @@ int
> eal_trace_args_save(const char *val)
> {
> 	struct trace *trace = trace_obj_get();
>-	char *trace_args;
>-	uint8_t nb_args;
>+	struct trace_arg *arg = malloc(sizeof(*arg));
Won't "malloc(sizeof(struct trace_arg))" be more readable ?

>
>-	nb_args = trace->args.nb_args;
>-
>-	if (nb_args >= TRACE_MAX_ARGS) {
>-		trace_err("ignoring trace %s as limit exceeds", val);
>-		return 0;
>+	if (arg == NULL) {
>+		trace_err("failed to allocate memory for %s", val);
>+		return -ENOMEM;
> 	}
>
>-	trace_args = calloc(1, (strlen(val) + 1));
>-	if (trace_args == NULL) {
>-		trace_err("fail to allocate memory for %s", val);
>+	arg->val = strdup(val);
>+	if (arg->val == NULL) {
>+		trace_err("failed to allocate memory for %s", val);
"arg" needs to be freed here.

> 		return -ENOMEM;
> 	}
>
>-	memcpy(trace_args, val, strlen(val));
>-	trace->args.args[nb_args++] = trace_args;
>-	trace->args.nb_args = nb_args;
>+	STAILQ_INSERT_TAIL(&trace->args, arg, next);
> 	return 0;
> }
>
>@@ -164,13 +159,13 @@ void
> eal_trace_args_free(void)
> {
> 	struct trace *trace = trace_obj_get();
>-	int i;
>+	struct trace_arg *arg;
>
>-	for (i = 0; i < trace->args.nb_args; i++) {
>-		if (trace->args.args[i]) {
>-			free((void *)trace->args.args[i]);
>-			trace->args.args[i] = NULL;
>-		}
>+	while (!STAILQ_EMPTY(&trace->args)) {
>+		arg = STAILQ_FIRST(&trace->args);
>+		STAILQ_REMOVE_HEAD(&trace->args, next);
>+		free(arg->val);
>+		free(arg);
> 	}
> }
>
>diff --git a/lib/librte_eal/common/eal_trace.h
>b/lib/librte_eal/common/eal_trace.h
>index 7d95bd2aa9..943b5ecbc5 100644
>--- a/lib/librte_eal/common/eal_trace.h
>+++ b/lib/librte_eal/common/eal_trace.h
>@@ -46,9 +46,9 @@ struct thread_mem_meta {
> 	enum trace_area_e area;
> };
>
>-struct trace_args {
>-	uint8_t nb_args;
>-	char *args[TRACE_MAX_ARGS];
>+struct trace_arg {
>+	STAILQ_ENTRY(trace_arg) next;
>+	char *val;
> };
>
> struct trace {
>@@ -59,7 +59,7 @@ struct trace {
> 	enum rte_trace_mode mode;
> 	rte_uuid_t uuid;
> 	uint32_t buff_len;
>-	struct trace_args args;
>+	STAILQ_HEAD(trace_arg_head, trace_arg) args;
"trace_arg_head" is not required. It can be removed.

> 	uint32_t nb_trace_points;
> 	uint32_t nb_trace_mem_list;
> 	struct thread_mem_meta *lcore_meta;
>--
>2.23.0