Re: [dpdk-dev] [EXT] [PATCH 16/39] eventdev: add eventmode CL options framework

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

Regards
Sunil Kumar Kori

>-----Original Message-----
>From: dev <dev-bounces@dpdk.org> On Behalf Of Anoob Joseph
>Sent: Monday, June 3, 2019 11:02 PM
>To: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Nikhil Rao
><nikhil.rao@intel.com>; Erik Gabriel Carrillo <erik.g.carrillo@intel.com>;
>Abhinandan Gujjar <abhinandan.gujjar@intel.com>; Bruce Richardson
><bruce.richardson@intel.com>; Pablo de Lara
><pablo.de.lara.guarch@intel.com>
>Cc: Anoob Joseph <anoobj@marvell.com>; Narayana Prasad Raju Athreya
><pathreya@marvell.com>; dev@dpdk.org; Lukas Bartosik
><lbartosik@marvell.com>; Pavan Nikhilesh Bhagavatula
><pbhagavatula@marvell.com>; Hemant Agrawal
><hemant.agrawal@nxp.com>; Nipun Gupta <nipun.gupta@nxp.com>; Harry
>van Haaren <harry.van.haaren@intel.com>; Mattias Rönnblom
><mattias.ronnblom@ericsson.com>; Liang Ma <liang.j.ma@intel.com>
>Subject: [EXT] [dpdk-dev] [PATCH 16/39] eventdev: add eventmode CL options
>framework
>
>External Email
>
>----------------------------------------------------------------------
>Adding usage prints and CL parsing routines for eventmode. Option to select
>packet transfer mode is also added.
>
>Signed-off-by: Anoob Joseph <anoobj@marvell.com>
>Signed-off-by: Lukasz Bartosik <lbartosik@marvell.com>
>---
> lib/librte_eventdev/rte_eventdev_version.map |   2 +
> lib/librte_eventdev/rte_eventmode_helper.c   | 128
>+++++++++++++++++++++++++++
> lib/librte_eventdev/rte_eventmode_helper.h   |  51 +++++++++++
> 3 files changed, 181 insertions(+)
>
>diff --git a/lib/librte_eventdev/rte_eventdev_version.map
>b/lib/librte_eventdev/rte_eventdev_version.map
>index 95fd089..1199064 100644
>--- a/lib/librte_eventdev/rte_eventdev_version.map
>+++ b/lib/librte_eventdev/rte_eventdev_version.map
>@@ -128,4 +128,6 @@ EXPERIMENTAL {
>
> 	rte_event_eth_rx_adapter_cb_register;
> 	rte_event_eth_rx_adapter_stats_get;
>+	rte_eventmode_helper_print_options_list;
>+	rte_eventmode_helper_print_options_description;
> };
>diff --git a/lib/librte_eventdev/rte_eventmode_helper.c
>b/lib/librte_eventdev/rte_eventmode_helper.c
>index f47970e..8119306 100644
>--- a/lib/librte_eventdev/rte_eventmode_helper.c
>+++ b/lib/librte_eventdev/rte_eventmode_helper.c
>@@ -1,7 +1,135 @@
> /* SPDX-License-Identifier: BSD-3-Clause
>  * Copyright (C) 2019 Marvell International Ltd.
>  */
>+#include <getopt.h>
>
> #include <rte_eventmode_helper.h>
>+#include <rte_malloc.h>
>
> #include "rte_eventmode_helper_internal.h"
>+
>+#define CMD_LINE_OPT_TRANSFER_MODE	"transfer-mode"
>+
>+static const char short_options[] =
>+	""
>+	;
>+
>+enum {
>+	/* long options mapped to a short option */
>+
>+	/* first long only option value must be >= 256, so that we won't
>+	 * conflict with short options
>+	 */
>+	CMD_LINE_OPT_MIN_NUM = 256,
>+	CMD_LINE_OPT_TRANSFER_MODE_NUM,
>+};
>+
>+static const struct option lgopts[] = {
>+	{CMD_LINE_OPT_TRANSFER_MODE, 1, 0,
>CMD_LINE_OPT_TRANSFER_MODE_NUM},
>+	{NULL, 0, 0, 0}
>+};
>+
>+/* Internal functions */
>+
>+static int32_t
>+internal_parse_decimal(const char *str) {
>+	char *end = NULL;
>+	unsigned long num;
>+
>+	num = strtoul(str, &end, 10);
>+	if ((str[0] == '\0') || (end == NULL) || (*end != '\0'))
>+		return -1;
>+
>+	return num;
>+}
>+
>+/* Global functions */
>+
>+void __rte_experimental
>+rte_eventmode_helper_print_options_list(void)
>+{
>+	fprintf(stderr, " --"
>+		" [--transfer-mode MODE]"
>+		);
>+}
>+
>+void __rte_experimental
>+rte_eventmode_helper_print_options_description(void)
>+{
>+	fprintf(stderr,
>+		"  --transfer-mode MODE\n"
>+		"               0: Packet transfer via polling (default)\n"
>+		"               1: Packet transfer via eventdev\n"
>+		"\n");
>+}
>+

Instead of exposing rte_eventmode_helper_print_options_* , we can maintain a page where all event_helper options are mentioned. Also application usage function can be updated like

        	fprintf(stderr, "%s [EAL options] --"
              " -p PORTMASK"
              " [-q NQ]",
	" -- [event helper options]"
              prgname);

 Advantages: Both functions will be removed from set of APIs and usage function will not be changed much. Suggesting the same methodology as used for EAL options.

>+static int
>+em_parse_transfer_mode(struct rte_eventmode_helper_conf *conf,
>+		const char *optarg)
>+{
>+	int32_t parsed_dec;
>+
>+	parsed_dec = internal_parse_decimal(optarg);
>+	if (parsed_dec !=
>RTE_EVENTMODE_HELPER_PKT_TRANSFER_MODE_POLL &&
>+	    parsed_dec !=
>RTE_EVENTMODE_HELPER_PKT_TRANSFER_MODE_EVENT) {
>+		RTE_EM_HLPR_LOG_ERR("Unsupported packet transfer
>mode");
>+		return -1;
>+	}
>+	conf->mode = parsed_dec;
>+	return 0;
>+}
>+
>+static void
>+em_initialize_helper_conf(struct rte_eventmode_helper_conf *conf) {
>+	/* Set default conf */
>+
>+	/* Packet transfer mode: poll */
>+	conf->mode =
>RTE_EVENTMODE_HELPER_PKT_TRANSFER_MODE_POLL;
>+}
>+
>+struct rte_eventmode_helper_conf *
>+rte_eventmode_helper_parse_args(int argc, char **argv) {
>+	int32_t opt, ret;
>+	struct rte_eventmode_helper_conf *conf = NULL;
>+
>+	/* Allocate memory for conf */
>+	conf = rte_zmalloc("eventmode-helper-conf",
>+			sizeof(struct rte_eventmode_helper_conf),
>+			RTE_CACHE_LINE_SIZE);
>+	if (conf == NULL) {
>+		RTE_EM_HLPR_LOG_ERR(
>+			"Failed allocating memory for eventmode helper
>conf");
>+			goto err;
>+	}
>+


Memory allocation for conf and conf->mode_params can be done in single alloc operation as given below:

	size = sizeof(struct rte_eventmode_helper_conf) + sizeof(struct eventmode_conf);
	conf = malloc(size);
	conf->mode_params = conf + 1;
	
Advantages: one NULL check will be avoided. To release the memory, need to free one pointer only. line of source code will be reduced.

>+	/* Initialize conf with default values */
>+	em_initialize_helper_conf(conf);
>+
>+	while ((opt = getopt_long(argc, argv, short_options,
>+				lgopts, NULL)) != EOF) {
>+		switch (opt) {
>+
>+		/* Packet transfer mode */
>+		case CMD_LINE_OPT_TRANSFER_MODE_NUM:
>+			ret = em_parse_transfer_mode(conf, optarg);
>+			if (ret < 0) {
>+				RTE_EM_HLPR_LOG_ERR(
>+					"Invalid packet transfer mode");
>+				goto err;
>+			}
>+			break;
>+		default:
>+			goto err;
>+		}
>+	}
>+	return conf;
>+
>+err:
>+	if (conf != NULL)
>+		rte_free(conf);
>+
>+	return NULL;
>+}
>diff --git a/lib/librte_eventdev/rte_eventmode_helper.h
>b/lib/librte_eventdev/rte_eventmode_helper.h
>index d32cd00..2a0cb30 100644
>--- a/lib/librte_eventdev/rte_eventmode_helper.h
>+++ b/lib/librte_eventdev/rte_eventmode_helper.h
>@@ -8,6 +8,57 @@
> extern "C" {
> #endif
>
>+#include <rte_compat.h>
>+
>+/* Packet transfer mode of the application */ enum
>+rte_eventmode_helper_pkt_transfer_mode {
>+	RTE_EVENTMODE_HELPER_PKT_TRANSFER_MODE_POLL = 0,
>+	RTE_EVENTMODE_HELPER_PKT_TRANSFER_MODE_EVENT,
>+};
>+
>+struct rte_eventmode_helper_conf {
>+	enum rte_eventmode_helper_pkt_transfer_mode mode;
>+		/**< Packet transfer mode of the application */
>+	void *mode_params;
>+		/**< Mode specific parameters */
>+};
>+
>+/* Common helper functions for command line parsing */
>+
>+/**
>+ * Print event mode options list
>+ *
>+ */
>+void __rte_experimental
>+rte_eventmode_helper_print_options_list(void);
>+
>+/**
>+ * Print event mode options description
>+ *
>+ */
>+void __rte_experimental
>+rte_eventmode_helper_print_options_description(void);
>+
>+/**
>+ * Parse event mode arguments
>+ *
>+ * The application can call this function in it's argument parsing
>+routine to
>+ * parse the event mode specific args and create the conf accordingly.
>+This
>+ * function is to be executed on the MASTER lcore only.
>+ *
>+ * @param argc
>+ *   A non-negative value. If it is greater than 0, the array members
>+ *   for argv[0] through argv[argc] (non-inclusive) shall contain pointers
>+ *   to strings.
>+ * @param argv
>+ *   An array of strings. The contents of the array, as well as the strings
>+ *   which are pointed to by the array, may be modified by this function.
>+ * @return
>+ *   Configuration generated by parsing the event mode args.
>+ */
>+struct rte_eventmode_helper_conf *
>+rte_eventmode_helper_parse_args(int argc, char **argv);
>+
> #ifdef __cplusplus
> }
> #endif
>--
>2.7.4