[dpdk-dev] [PATCH 6/9] mem: add support for hugepage-unlink mode

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

Unlink hugepages after creating them, to honor the hugepage-unlink mode.
We cannot resize non-existing files, so make single file segments
explicitly unsupported.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---

Notes:
    RFC->v1:
    - Use --huge-unlink only

 lib/librte_eal/linuxapp/eal/eal_memalloc.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_memalloc.c b/lib/librte_eal/linuxapp/eal/eal_memalloc.c
index 8c11f98c9..f1b6d9744 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memalloc.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memalloc.c
@@ -512,6 +512,13 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
 				__func__, strerror(errno));
 			goto resized;
 		}
+		if (internal_config.hugepage_unlink) {
+			if (unlink(path)) {
+				RTE_LOG(DEBUG, EAL, "%s(): unlink() failed: %s\n",
+					__func__, strerror(errno));
+				goto resized;
+			}
+		}
 	}
 
 	/*
@@ -592,7 +599,8 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
 		/* ignore failure, can't make it any worse */
 	} else {
 		/* only remove file if we can take out a write lock */
-		if (lock(fd, LOCK_EX) == 1)
+		if (internal_config.hugepage_unlink == 0 &&
+				lock(fd, LOCK_EX) == 1)
 			unlink(path);
 		close(fd);
 	}
@@ -617,6 +625,12 @@ free_seg(struct rte_memseg *ms, struct hugepage_info *hi,
 		return -1;
 	}
 
+	/* if we've already unlinked the page, nothing needs to be done */
+	if (internal_config.hugepage_unlink) {
+		memset(ms, 0, sizeof(*ms));
+		return 0;
+	}
+
 	/* if we are not in single file segments mode, we're going to unmap the
 	 * segment and thus drop the lock on original fd, but hugepage dir is
 	 * now locked so we can take out another one without races.
-- 
2.17.0