[dpdk-stable] [PATCH v5 1/1] fbarray: fix duplicated fbarray file in secondary

[yasufum.o at gmail.com]

From: Yasufumi Ogawa <ogawa.yasufumi at lab.ntt.co.jp>

In secondary_msl_create_walk(), it creates a file for fbarrays with its
PID for reserving unique name among secondary processes. However, it
does not work if several secondaries run as app containers because each
of containerized secondary has PID 1, and failed to reserve unique name
other than first one. To reserve unique name in each of containers, use
hostname instead of PID only if PID is 1.

Cc: stable at dpdk.org

Signed-off-by: Yasufumi Ogawa <yasufum.o at gmail.com>
---
 lib/librte_eal/linux/eal/eal_memalloc.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/linux/eal/eal_memalloc.c b/lib/librte_eal/linux/eal/eal_memalloc.c
index af6d0d023..699079791 100644
--- a/lib/librte_eal/linux/eal/eal_memalloc.c
+++ b/lib/librte_eal/linux/eal/eal_memalloc.c
@@ -1365,6 +1365,7 @@ secondary_msl_create_walk(const struct rte_memseg_list *msl,
 	struct rte_memseg_list *primary_msl, *local_msl;
 	char name[PATH_MAX];
 	int msl_idx, ret;
+	char proc_id[HOST_NAME_MAX] = { 0 };
 
 	if (msl->external)
 		return 0;
@@ -1374,8 +1375,18 @@ secondary_msl_create_walk(const struct rte_memseg_list *msl,
 	local_msl = &local_memsegs[msl_idx];
 
 	/* create distinct fbarrays for each secondary */
-	snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%i",
-		primary_msl->memseg_arr.name, getpid());
+	/* If run secondary in a container, the name of fbarray file should
+	 * not be decided with pid because getpid() always returns 1.
+	 * In docker, hostname is assigned as a short form of full container
+	 * ID. So use hostname as unique ID among containers instead.
+	 */
+	if (getpid() == 1)
+		gethostname(proc_id, HOST_NAME_MAX);
+	else
+		sprintf(proc_id, "%d", (int)getpid());
+
+	snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%s",
+			primary_msl->memseg_arr.name, proc_id);
 
 	ret = rte_fbarray_init(&local_msl->memseg_arr, name,
 		primary_msl->memseg_arr.len,
-- 
2.17.1