[dpdk-dev] [PATCH v2 5/9] memalloc: track page fd's in non-single file mode

[Anatoly Burakov <anatoly.burakov@intel.com>]

Previously, we were only tracking lock file fd's in single-file
segments mode, but did not track fd's in non-single file mode
because we didn't need to (mmap() call still kept the lock). Now
that we are going to expose these fd's to the world, we need to
have access to them, so track them even in non-single file
segments mode.

We don't need to close fd's after mmap() because we're still
tracking them in an fd list. Also, for anonymous hugepages mode,
fd will always be -1 so exit early on error.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_eal/linuxapp/eal/eal_memalloc.c | 44 ++++++++++++----------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_memalloc.c b/lib/librte_eal/linuxapp/eal/eal_memalloc.c
index 14bc5dce9..7d536350e 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memalloc.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memalloc.c
@@ -318,18 +318,24 @@ get_seg_fd(char *path, int buflen, struct hugepage_info *hi,
 		/* create a hugepage file path */
 		eal_get_hugefile_path(path, buflen, hi->hugedir,
 				list_idx * RTE_MAX_MEMSEG_PER_LIST + seg_idx);
-		fd = open(path, O_CREAT | O_RDWR, 0600);
+
+		fd = fd_list[list_idx].fds[seg_idx];
+
 		if (fd < 0) {
-			RTE_LOG(DEBUG, EAL, "%s(): open failed: %s\n", __func__,
-					strerror(errno));
-			return -1;
-		}
-		/* take out a read lock */
-		if (lock(fd, LOCK_SH) < 0) {
-			RTE_LOG(ERR, EAL, "%s(): lock failed: %s\n",
-				__func__, strerror(errno));
-			close(fd);
-			return -1;
+			fd = open(path, O_CREAT | O_RDWR, 0600);
+			if (fd < 0) {
+				RTE_LOG(DEBUG, EAL, "%s(): open failed: %s\n",
+					__func__, strerror(errno));
+				return -1;
+			}
+			/* take out a read lock */
+			if (lock(fd, LOCK_SH) < 0) {
+				RTE_LOG(ERR, EAL, "%s(): lock failed: %s\n",
+					__func__, strerror(errno));
+				close(fd);
+				return -1;
+			}
+			fd_list[list_idx].fds[seg_idx] = fd;
 		}
 	}
 	return fd;
@@ -601,10 +607,6 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
 		goto mapped;
 	}
 #endif
-	/* for non-single file segments that aren't in-memory, we can close fd
-	 * here */
-	if (!internal_config.single_file_segments && !internal_config.in_memory)
-		close(fd);
 
 	ms->addr = addr;
 	ms->hugepage_sz = alloc_sz;
@@ -634,7 +636,10 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
 		RTE_LOG(CRIT, EAL, "Can't mmap holes in our virtual address space\n");
 	}
 resized:
-	/* in-memory mode will never be single-file-segments mode */
+	/* some codepaths will return negative fd, so exit early */
+	if (fd < 0)
+		return -1;
+
 	if (internal_config.single_file_segments) {
 		resize_hugefile(fd, path, list_idx, seg_idx, map_offset,
 				alloc_sz, false);
@@ -646,6 +651,7 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
 				lock(fd, LOCK_EX) == 1)
 			unlink(path);
 		close(fd);
+		fd_list[list_idx].fds[seg_idx] = -1;
 	}
 	return -1;
 }
@@ -700,6 +706,7 @@ free_seg(struct rte_memseg *ms, struct hugepage_info *hi,
 		}
 		/* closing fd will drop the lock */
 		close(fd);
+		fd_list[list_idx].fds[seg_idx] = -1;
 	}
 
 	memset(ms, 0, sizeof(*ms));
@@ -1364,8 +1371,7 @@ eal_memalloc_init(void)
 			return -1;
 
 	/* initialize all of the fd lists */
-	if (internal_config.single_file_segments)
-		if (rte_memseg_list_walk(fd_list_create_walk, NULL))
-			return -1;
+	if (rte_memseg_list_walk(fd_list_create_walk, NULL))
+		return -1;
 	return 0;
 }
-- 
2.17.1