[dpdk-dev] [PATCH v3] log: add API to check if a logtype can log in a given level

[Ferruh Yigit <ferruh.yigit@intel.com>]

This is a helper function in case components would like to do more work
than just logging a message based on log level, like for example
collecting some stats if the log type is DEBUG etc..

A few existing relevant usage converted to this new API.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Hyong Youb Kim <hyonkim@cisco.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
---
Cc: David Marchand <david.marchand@redhat.com>
Cc: Thomas Monjalon <thomas@monjalon.net>
Cc: Stephen Hemminger <stephen@networkplumber.org>

v2:
* Convert API return type to 'bool'. Removed custom definitions from
  'ionic' PMD for this.

v3:
* Update function comment
* Use new function in `rte_vlog()`
---
 drivers/bus/fslmc/fslmc_bus.c                |  7 +------
 drivers/common/qat/qat_logs.c                |  7 ++-----
 drivers/net/enic/enic_fm_flow.c              |  2 +-
 drivers/net/mlx5/mlx5_mr.c                   |  2 +-
 lib/librte_eal/common/eal_common_log.c       | 22 +++++++++++++++++---
 lib/librte_eal/common/include/rte_log.h      | 14 +++++++++++++
 lib/librte_eal/rte_eal_version.map           |  3 +++
 lib/librte_flow_classify/rte_flow_classify.c |  7 ++-----
 8 files changed, 43 insertions(+), 21 deletions(-)

diff --git a/drivers/bus/fslmc/fslmc_bus.c b/drivers/bus/fslmc/fslmc_bus.c
index b3e964aa9..afbd82e8d 100644
--- a/drivers/bus/fslmc/fslmc_bus.c
+++ b/drivers/bus/fslmc/fslmc_bus.c
@@ -115,14 +115,9 @@ static void
 dump_device_list(void)
 {
 	struct rte_dpaa2_device *dev;
-	uint32_t global_log_level;
-	int local_log_level;
 
 	/* Only if the log level has been set to Debugging, print list */
-	global_log_level = rte_log_get_global_level();
-	local_log_level = rte_log_get_level(dpaa2_logtype_bus);
-	if (global_log_level == RTE_LOG_DEBUG ||
-	    local_log_level == RTE_LOG_DEBUG) {
+	if (rte_log_can_log(dpaa2_logtype_bus, RTE_LOG_DEBUG)) {
 		DPAA2_BUS_LOG(DEBUG, "List of devices scanned on bus:");
 		TAILQ_FOREACH(dev, &rte_fslmc_bus.device_list, next) {
 			DPAA2_BUS_LOG(DEBUG, "\t\t%s", dev->device.name);
diff --git a/drivers/common/qat/qat_logs.c b/drivers/common/qat/qat_logs.c
index f97aba19d..dfd0cbe5d 100644
--- a/drivers/common/qat/qat_logs.c
+++ b/drivers/common/qat/qat_logs.c
@@ -14,12 +14,9 @@ int
 qat_hexdump_log(uint32_t level, uint32_t logtype, const char *title,
 		const void *buf, unsigned int len)
 {
-	if (level > rte_log_get_global_level())
-		return 0;
-	if (level > (uint32_t)(rte_log_get_level(logtype)))
-		return 0;
+	if (rte_log_can_log(logtype, level))
+		rte_hexdump(rte_log_get_stream(), title, buf, len);
 
-	rte_hexdump(rte_log_get_stream(), title, buf, len);
 	return 0;
 }
 
diff --git a/drivers/net/enic/enic_fm_flow.c b/drivers/net/enic/enic_fm_flow.c
index c0ddfe9ba..d815f369e 100644
--- a/drivers/net/enic/enic_fm_flow.c
+++ b/drivers/net/enic/enic_fm_flow.c
@@ -1504,7 +1504,7 @@ enic_fm_dump_tcam_entry(const struct fm_tcam_match_entry *fm_match,
 			const struct fm_action *fm_action,
 			uint8_t ingress)
 {
-	if (rte_log_get_level(enic_pmd_logtype) < (int)RTE_LOG_DEBUG)
+	if (!rte_log_can_log(enic_pmd_logtype, RTE_LOG_DEBUG))
 		return;
 	enic_fm_dump_tcam_match(fm_match, ingress);
 	enic_fm_dump_tcam_actions(fm_action);
diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index cb97c876e..6aa578646 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c
@@ -1597,7 +1597,7 @@ mlx5_mr_release(struct mlx5_ibv_shared *sh)
 {
 	struct mlx5_mr *mr_next;
 
-	if (rte_log_get_level(mlx5_logtype) == RTE_LOG_DEBUG)
+	if (rte_log_can_log(mlx5_logtype, RTE_LOG_DEBUG))
 		mlx5_mr_dump_dev(sh);
 	rte_rwlock_write_lock(&sh->mr.rwlock);
 	/* Detach from MR list and move to free list. */
diff --git a/lib/librte_eal/common/eal_common_log.c b/lib/librte_eal/common/eal_common_log.c
index c0efd5214..7647a916e 100644
--- a/lib/librte_eal/common/eal_common_log.c
+++ b/lib/librte_eal/common/eal_common_log.c
@@ -112,6 +112,24 @@ rte_log_get_level(uint32_t type)
 	return rte_logs.dynamic_types[type].loglevel;
 }
 
+bool
+rte_log_can_log(uint32_t logtype, uint32_t level)
+{
+	int log_level;
+
+	if (level > rte_log_get_global_level())
+		return false;
+
+	log_level = rte_log_get_level(logtype);
+	if (log_level < 0)
+		return false;
+
+	if (level > (uint32_t)log_level)
+		return false;
+
+	return true;
+}
+
 int
 rte_log_set_level(uint32_t type, uint32_t level)
 {
@@ -417,11 +435,9 @@ rte_vlog(uint32_t level, uint32_t logtype, const char *format, va_list ap)
 	FILE *f = rte_log_get_stream();
 	int ret;
 
-	if (level > rte_logs.level)
-		return 0;
 	if (logtype >= rte_logs.dynamic_types_len)
 		return -1;
-	if (level > rte_logs.dynamic_types[logtype].loglevel)
+	if (!rte_log_can_log(logtype, level))
 		return 0;
 
 	/* save loglevel and logtype in a global per-lcore variable */
diff --git a/lib/librte_eal/common/include/rte_log.h b/lib/librte_eal/common/include/rte_log.h
index 1bb0e6694..7f5cdbb39 100644
--- a/lib/librte_eal/common/include/rte_log.h
+++ b/lib/librte_eal/common/include/rte_log.h
@@ -20,6 +20,7 @@ extern "C" {
 #include <stdint.h>
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <sys/queue.h>
 
 #include <rte_common.h>
@@ -143,6 +144,19 @@ uint32_t rte_log_get_global_level(void);
  */
 int rte_log_get_level(uint32_t logtype);
 
+/**
+ * For a given `logtype`, check if a log with `loglevel` can be printed.
+ *
+ * @param logtype
+ *   The log type identifier
+ * @param loglevel
+ *   Log level. A value between RTE_LOG_EMERG (1) and RTE_LOG_DEBUG (8).
+ * @return
+ * Returns 'true' if log can be printed and 'false' if it can't.
+ */
+__rte_experimental
+bool rte_log_can_log(uint32_t logtype, uint32_t loglevel);
+
 /**
  * Set the log level for a given type based on shell pattern.
  *
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index 6cf507068..f9ede5b41 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -335,4 +335,7 @@ EXPERIMENTAL {
 
 	# added in 20.02
 	rte_thread_is_intr;
+
+	# added in 20.05
+	rte_log_can_log;
 };
diff --git a/lib/librte_flow_classify/rte_flow_classify.c b/lib/librte_flow_classify/rte_flow_classify.c
index 5ff585803..6022064d8 100644
--- a/lib/librte_flow_classify/rte_flow_classify.c
+++ b/lib/librte_flow_classify/rte_flow_classify.c
@@ -417,7 +417,6 @@ static struct rte_flow_classify_rule *
 allocate_acl_ipv4_5tuple_rule(struct rte_flow_classifier *cls)
 {
 	struct rte_flow_classify_rule *rule;
-	int log_level;
 
 	rule = malloc(sizeof(struct rte_flow_classify_rule));
 	if (!rule)
@@ -466,9 +465,7 @@ allocate_acl_ipv4_5tuple_rule(struct rte_flow_classifier *cls)
 			cls->ntuple_filter.dst_port_mask;
 	rule->rules.u.ipv4_5tuple.dst_port = cls->ntuple_filter.dst_port;
 
-	log_level = rte_log_get_level(librte_flow_classify_logtype);
-
-	if (log_level == RTE_LOG_DEBUG)
+	if (rte_log_can_log(librte_flow_classify_logtype, RTE_LOG_DEBUG))
 		print_acl_ipv4_key_add(&rule->u.key.key_add);
 
 	/* key delete values */
@@ -476,7 +473,7 @@ allocate_acl_ipv4_5tuple_rule(struct rte_flow_classifier *cls)
 	       &rule->u.key.key_add.field_value[PROTO_FIELD_IPV4],
 	       NUM_FIELDS_IPV4 * sizeof(struct rte_acl_field));
 
-	if (log_level == RTE_LOG_DEBUG)
+	if (rte_log_can_log(librte_flow_classify_logtype, RTE_LOG_DEBUG))
 		print_acl_ipv4_key_delete(&rule->u.key.key_del);
 
 	return rule;
-- 
2.24.1