From: Anatoly Burakov Date: Tue, 4 Sep 2018 15:15:48 +0000 (+0100) Subject: mem: add external API to retrieve page fd X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=41dbdb68723b;p=dpdk.git mem: add external API to retrieve page fd Now that we can retrieve page fd's internally, we can expose it as an external API. This will add two flavors of API - thread-safe and non-thread-safe. Fix up internal API's to return values we need without modifying rte_errno internally if called from within EAL. We do not want calling code to accidentally close an internal fd, so we make a duplicate of it before we return it to the user. Caller is therefore responsible for closing this fd. Signed-off-by: Anatoly Burakov Reviewed-by: Maxime Coquelin --- diff --git a/lib/librte_eal/bsdapp/eal/eal_memalloc.c b/lib/librte_eal/bsdapp/eal/eal_memalloc.c index a5fb09f715..80e4c3d4f3 100644 --- a/lib/librte_eal/bsdapp/eal/eal_memalloc.c +++ b/lib/librte_eal/bsdapp/eal/eal_memalloc.c @@ -4,6 +4,7 @@ #include +#include #include #include @@ -50,13 +51,13 @@ eal_memalloc_sync_with_primary(void) int eal_memalloc_get_seg_fd(int list_idx, int seg_idx) { - return -1; + return -ENOTSUP; } int eal_memalloc_set_seg_fd(int list_idx, int seg_idx, int fd) { - return -1; + return -ENOTSUP; } int diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c index 034c2026a8..4a80deaf52 100644 --- a/lib/librte_eal/common/eal_common_memory.c +++ b/lib/librte_eal/common/eal_common_memory.c @@ -550,6 +550,55 @@ rte_memseg_list_walk(rte_memseg_list_walk_t func, void *arg) return ret; } +int __rte_experimental +rte_memseg_get_fd_thread_unsafe(const struct rte_memseg *ms) +{ + struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config; + struct rte_memseg_list *msl; + struct rte_fbarray *arr; + int msl_idx, seg_idx, ret; + + if (ms == NULL) { + rte_errno = EINVAL; + return -1; + } + + msl = rte_mem_virt2memseg_list(ms->addr); + if (msl == NULL) { + rte_errno = EINVAL; + return -1; + } + arr = &msl->memseg_arr; + + msl_idx = msl - mcfg->memsegs; + seg_idx = rte_fbarray_find_idx(arr, ms); + + if (!rte_fbarray_is_used(arr, seg_idx)) { + rte_errno = ENOENT; + return -1; + } + + ret = eal_memalloc_get_seg_fd(msl_idx, seg_idx); + if (ret < 0) { + rte_errno = -ret; + ret = -1; + } + return ret; +} + +int __rte_experimental +rte_memseg_get_fd(const struct rte_memseg *ms) +{ + struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config; + int ret; + + rte_rwlock_read_lock(&mcfg->memory_hotplug_lock); + ret = rte_memseg_get_fd_thread_unsafe(ms); + rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock); + + return ret; +} + /* init memory subsystem */ int rte_eal_memory_init(void) diff --git a/lib/librte_eal/common/eal_memalloc.h b/lib/librte_eal/common/eal_memalloc.h index a46c69c720..70a214de4e 100644 --- a/lib/librte_eal/common/eal_memalloc.h +++ b/lib/librte_eal/common/eal_memalloc.h @@ -76,9 +76,11 @@ eal_memalloc_mem_alloc_validator_unregister(const char *name, int socket_id); int eal_memalloc_mem_alloc_validate(int socket_id, size_t new_len); +/* returns fd or -errno */ int eal_memalloc_get_seg_fd(int list_idx, int seg_idx); +/* returns 0 or -errno */ int eal_memalloc_set_seg_fd(int list_idx, int seg_idx, int fd); diff --git a/lib/librte_eal/common/include/rte_memory.h b/lib/librte_eal/common/include/rte_memory.h index c4b7f4cff1..0d2a30056e 100644 --- a/lib/librte_eal/common/include/rte_memory.h +++ b/lib/librte_eal/common/include/rte_memory.h @@ -317,6 +317,54 @@ rte_memseg_contig_walk_thread_unsafe(rte_memseg_contig_walk_t func, void *arg); int __rte_experimental rte_memseg_list_walk_thread_unsafe(rte_memseg_list_walk_t func, void *arg); +/** + * Return file descriptor associated with a particular memseg (if available). + * + * @note This function read-locks the memory hotplug subsystem, and thus cannot + * be used within memory-related callback functions. + * + * @note This returns an internal file descriptor. Performing any operations on + * this file descriptor is inherently dangerous, so it should be treated + * as read-only for all intents and purposes. + * + * @param ms + * A pointer to memseg for which to get file descriptor. + * + * @return + * Valid file descriptor in case of success. + * -1 in case of error, with ``rte_errno`` set to the following values: + * - EINVAL - ``ms`` pointer was NULL or did not point to a valid memseg + * - ENODEV - ``ms`` fd is not available + * - ENOENT - ``ms`` is an unused segment + * - ENOTSUP - segment fd's are not supported + */ +int __rte_experimental +rte_memseg_get_fd(const struct rte_memseg *ms); + +/** + * Return file descriptor associated with a particular memseg (if available). + * + * @note This function does not perform any locking, and is only safe to call + * from within memory-related callback functions. + * + * @note This returns an internal file descriptor. Performing any operations on + * this file descriptor is inherently dangerous, so it should be treated + * as read-only for all intents and purposes. + * + * @param ms + * A pointer to memseg for which to get file descriptor. + * + * @return + * Valid file descriptor in case of success. + * -1 in case of error, with ``rte_errno`` set to the following values: + * - EINVAL - ``ms`` pointer was NULL or did not point to a valid memseg + * - ENODEV - ``ms`` fd is not available + * - ENOENT - ``ms`` is an unused segment + * - ENOTSUP - segment fd's are not supported + */ +int __rte_experimental +rte_memseg_get_fd_thread_unsafe(const struct rte_memseg *ms); + /** * Dump the physical memory layout to a file. * diff --git a/lib/librte_eal/linuxapp/eal/eal_memalloc.c b/lib/librte_eal/linuxapp/eal/eal_memalloc.c index b820989e90..21f8427533 100644 --- a/lib/librte_eal/linuxapp/eal/eal_memalloc.c +++ b/lib/librte_eal/linuxapp/eal/eal_memalloc.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include @@ -1381,7 +1382,7 @@ eal_memalloc_set_seg_fd(int list_idx, int seg_idx, int fd) int len = mcfg->memsegs[list_idx].memseg_arr.len; if (alloc_list(list_idx, len) < 0) - return -1; + return -ENOMEM; } fd_list[list_idx].fds[seg_idx] = fd; @@ -1391,12 +1392,18 @@ eal_memalloc_set_seg_fd(int list_idx, int seg_idx, int fd) int eal_memalloc_get_seg_fd(int list_idx, int seg_idx) { - if (internal_config.single_file_segments) - return fd_list[list_idx].memseg_list_fd; - /* list not initialized */ - if (fd_list[list_idx].len == 0) - return -1; - return fd_list[list_idx].fds[seg_idx]; + int fd; + if (internal_config.single_file_segments) { + fd = fd_list[list_idx].memseg_list_fd; + } else if (fd_list[list_idx].len == 0) { + /* list not initialized */ + fd = -1; + } else { + fd = fd_list[list_idx].fds[seg_idx]; + } + if (fd < 0) + return -ENODEV; + return fd; } int diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map index 2031d7b15e..fb200dec5c 100644 --- a/lib/librte_eal/rte_eal_version.map +++ b/lib/librte_eal/rte_eal_version.map @@ -327,6 +327,8 @@ EXPERIMENTAL { rte_mem_virt2memseg_list; rte_memseg_contig_walk; rte_memseg_contig_walk_thread_unsafe; + rte_memseg_get_fd; + rte_memseg_get_fd_thread_unsafe; rte_memseg_list_walk; rte_memseg_list_walk_thread_unsafe; rte_memseg_walk;