[dpdk-dev] [PATCH] eal: fix log level/type retrieving on a standard pthread

[Olivier Matz <olivier.matz@6wind.com>]

From: Maxime Leroy <maxime.leroy@6wind.com>

The functions rte_log_cur_msg_loglevel() and rte_log_cur_msg_logtype()
return the current log level/type for the message being processed. They
are used when implementing a user-defined logging stream.

The current log levels and types were stored in a table indexed by the
lcore_id, only returning a valid value for dataplane threads. Setting
and getting these values in a non dataplane thread was ignored, using
the global value instead.

To fix this issue, a per-thread variable could be used (with
RTE_DEFINE_PER_LCORE), allowing any pthread to set and retrieve its
current log level or type.

Signed-off-by: Maxime Leroy <maxime.leroy@6wind.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/librte_eal/common/eal_common_log.c | 25 +++++++------------------
 1 file changed, 7 insertions(+), 18 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_log.c b/lib/librte_eal/common/eal_common_log.c
index 64aa79f..9526095 100644
--- a/lib/librte_eal/common/eal_common_log.c
+++ b/lib/librte_eal/common/eal_common_log.c
@@ -98,9 +98,10 @@ static int history_enabled = 1;
 struct log_cur_msg {
 	uint32_t loglevel; /**< log level - see rte_log.h */
 	uint32_t logtype;  /**< log type  - see rte_log.h */
-} __rte_cache_aligned;
-static struct log_cur_msg log_cur_msg[RTE_MAX_LCORE]; /**< per core log */
+};
 
+ /* per core log */
+static RTE_DEFINE_PER_LCORE(struct log_cur_msg, log_cur_msg);
 
 /* default logs */
 
@@ -205,21 +206,13 @@ rte_get_log_type(void)
 /* get the current loglevel for the message beeing processed */
 int rte_log_cur_msg_loglevel(void)
 {
-	unsigned lcore_id;
-	lcore_id = rte_lcore_id();
-	if (lcore_id >= RTE_MAX_LCORE)
-		return rte_get_log_level();
-	return log_cur_msg[lcore_id].loglevel;
+	return RTE_PER_LCORE(log_cur_msg).loglevel;
 }
 
 /* get the current logtype for the message beeing processed */
 int rte_log_cur_msg_logtype(void)
 {
-	unsigned lcore_id;
-	lcore_id = rte_lcore_id();
-	if (lcore_id >= RTE_MAX_LCORE)
-		return rte_get_log_type();
-	return log_cur_msg[lcore_id].logtype;
+	return RTE_PER_LCORE(log_cur_msg).logtype;
 }
 
 /* Dump log history to file */
@@ -273,17 +266,13 @@ rte_vlog(uint32_t level, uint32_t logtype, const char *format, va_list ap)
 {
 	int ret;
 	FILE *f = rte_logs.file;
-	unsigned lcore_id;
 
 	if ((level > rte_logs.level) || !(logtype & rte_logs.type))
 		return 0;
 
 	/* save loglevel and logtype in a global per-lcore variable */
-	lcore_id = rte_lcore_id();
-	if (lcore_id < RTE_MAX_LCORE) {
-		log_cur_msg[lcore_id].loglevel = level;
-		log_cur_msg[lcore_id].logtype = logtype;
-	}
+	RTE_PER_LCORE(log_cur_msg).loglevel = level;
+	RTE_PER_LCORE(log_cur_msg).logtype = logtype;
 
 	ret = vfprintf(f, format, ap);
 	fflush(f);
-- 
2.8.0.rc3