[dpdk-dev] [PATCH v8 1/1] fbarray: fix duplicated fbarray file in secondary

[Yasufumi Ogawa]

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 in addition to PID.

Signed-off-by: Yasufumi Ogawa <ogawa.yasufumi at lab.ntt.co.jp>
---
 lib/librte_eal/common/include/rte_fbarray.h |  7 ++++++-
 lib/librte_eal/linux/eal/eal_memalloc.c     | 11 ++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/lib/librte_eal/common/include/rte_fbarray.h b/lib/librte_eal/common/include/rte_fbarray.h
index 6dccdbec9..df003b8dc 100644
--- a/lib/librte_eal/common/include/rte_fbarray.h
+++ b/lib/librte_eal/common/include/rte_fbarray.h
@@ -39,7 +39,12 @@ extern "C" {
 #include <rte_compat.h>
 #include <rte_rwlock.h>
 
-#define RTE_FBARRAY_NAME_LEN 64
+/* Filename of fbarray is defined as a combination of several params
+ * such as "fbarray_memseg-1048576k-0-0_PID_HOSTNAME".
+ * The length of string before PID can be 32bytes, and the length of
+ * PID can be 7bytes maximamly. Final 1 byte is for null terminator.
+ */
+#define RTE_FBARRAY_NAME_LEN (32 + 7 + 1 + HOST_NAME_MAX + 1)
 
 struct rte_fbarray {
 	char name[RTE_FBARRAY_NAME_LEN]; /**< name associated with an array */
diff --git a/lib/librte_eal/linux/eal/eal_memalloc.c b/lib/librte_eal/linux/eal/eal_memalloc.c
index af6d0d023..8c50d3355 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 hostname[HOST_NAME_MAX+1] = { 0 };
 
 	if (msl->external)
 		return 0;
@@ -1373,9 +1374,13 @@ secondary_msl_create_walk(const struct rte_memseg_list *msl,
 	primary_msl = &mcfg->memsegs[msl_idx];
 	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());
+	/* Create distinct fbarrays for each secondary by using PID and
+	 * hostname. The reason why using hostname is because PID could be
+	 * duplicated among secondaries if it is launched in a container.
+	 */
+	gethostname(hostname, sizeof(hostname));
+	snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%d_%s",
+			primary_msl->memseg_arr.name, (int)getpid(), hostname);
 
 	ret = rte_fbarray_init(&local_msl->memseg_arr, name,
 		primary_msl->memseg_arr.len,
-- 
2.17.1