From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from EUR01-VE1-obe.outbound.protection.outlook.com (mail-ve1eur01on0065.outbound.protection.outlook.com [104.47.1.65]) by dpdk.org (Postfix) with ESMTP id 0B05A728E for ; Fri, 27 Apr 2018 02:01:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Mellanox.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=lYnW5ixNj4Xzmv6E7XQUjkf1WKeSCDHvPTDfWzptsGw=; b=iTROOJ+AD2fiSVVjW3GnCRK+NrtgXOancDvKIWsp2GhU8T544ksBRgrAAQk4eOGxLkDl9qDmTvbCfNUKWYK50j4coKT5mBFJfkzDzAGgZrjz/zXSAjAXruYkTV45+Xkel1Mio3H2MMLMN5myePl+9qxn9BWZHk08RzOBTsn1Sk0= Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=yskoh@mellanox.com; Received: from mellanox.com (209.116.155.178) by HE1PR0501MB2042.eurprd05.prod.outlook.com (2603:10a6:3:35::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256) id 15.20.696.15; Fri, 27 Apr 2018 00:01:35 +0000 From: Yongseok Koh To: wenzhuo.lu@intel.com, jingjing.wu@intel.com, olivier.matz@6wind.com Cc: dev@dpdk.org, konstantin.ananyev@intel.com, arybchenko@solarflare.com, stephen@networkplumber.org, thomas@monjalon.net, adrien.mazarguil@6wind.com, nelio.laranjeiro@6wind.com, Yongseok Koh Date: Thu, 26 Apr 2018 17:01:22 -0700 Message-Id: <20180427000123.31888-1-yskoh@mellanox.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180310012532.15809-1-yskoh@mellanox.com> References: <20180310012532.15809-1-yskoh@mellanox.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [209.116.155.178] X-ClientProxiedBy: BN6PR1101CA0006.namprd11.prod.outlook.com (2603:10b6:405:4a::16) To HE1PR0501MB2042.eurprd05.prod.outlook.com (2603:10a6:3:35::20) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: UriScan:; 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Attaching an external buffer is quite similar to mbuf indirection in replacing buffer addresses and length of a mbuf, but a few differences: - When an indirect mbuf is attached, refcnt of the direct mbuf would be 2 as long as the direct mbuf itself isn't freed after the attachment. In such cases, the buffer area of a direct mbuf must be read-only. But external buffer has its own refcnt and it starts from 1. Unless multiple mbufs are attached to a mbuf having an external buffer, the external buffer is writable. - There's no need to allocate buffer from a mempool. Any buffer can be attached with appropriate free callback. - Smaller metadata is required to maintain shared data such as refcnt. Signed-off-by: Yongseok Koh Acked-by: Konstantin Ananyev Acked-by: Olivier Matz --- Deprecation of RTE_MBUF_INDIRECT() will follow after integration of this patch. ** This patch can pass the mbuf_autotest. ** Submitting only non-mlx5 patches to meet deadline for RC1. mlx5 patches will be submitted separately rebased on a differnet patchset which accommodates new memory hotplug design to mlx PMDs. v7: * make buf_len param [in,out] in rte_pktmbuf_ext_shinfo_init_helper(). * a minor change from review. v6: * rte_pktmbuf_attach_extbuf() doesn't take NULL shinfo. Instead, rte_pktmbuf_ext_shinfo_init_helper() is added. * bug fix in rte_pktmbuf_attach() - shinfo wasn't saved to mi. * minor changes from review. v5: * rte_pktmbuf_attach_extbuf() sets headroom to 0. * if shinfo is provided when attaching, user should initialize it. * minor changes from review. v4: * rte_pktmbuf_attach_extbuf() takes new arguments - buf_iova and shinfo. user can pass memory for shared data via shinfo argument. * minor changes from review. v3: * implement external buffer attachment instead of introducing buf_off for mbuf indirection. lib/librte_mbuf/rte_mbuf.h | 337 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 308 insertions(+), 29 deletions(-) diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index 0cd6a1c6b..4fd9a0d9e 100644 --- a/lib/librte_mbuf/rte_mbuf.h +++ b/lib/librte_mbuf/rte_mbuf.h @@ -345,7 +345,10 @@ extern "C" { PKT_TX_MACSEC | \ PKT_TX_SEC_OFFLOAD) -#define __RESERVED (1ULL << 61) /**< reserved for future mbuf use */ +/** + * Mbuf having an external buffer attached. shinfo in mbuf must be filled. + */ +#define EXT_ATTACHED_MBUF (1ULL << 61) #define IND_ATTACHED_MBUF (1ULL << 62) /**< Indirect attached mbuf */ @@ -585,8 +588,27 @@ struct rte_mbuf { /** Sequence number. See also rte_reorder_insert(). */ uint32_t seqn; + /** Shared data for external buffer attached to mbuf. See + * rte_pktmbuf_attach_extbuf(). + */ + struct rte_mbuf_ext_shared_info *shinfo; + } __rte_cache_aligned; +/** + * Function typedef of callback to free externally attached buffer. + */ +typedef void (*rte_mbuf_extbuf_free_callback_t)(void *addr, void *opaque); + +/** + * Shared data at the end of an external buffer. + */ +struct rte_mbuf_ext_shared_info { + rte_mbuf_extbuf_free_callback_t free_cb; /**< Free callback function */ + void *fcb_opaque; /**< Free callback argument */ + rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */ +}; + /**< Maximum number of nb_segs allowed. */ #define RTE_MBUF_MAX_NB_SEGS UINT16_MAX @@ -707,14 +729,34 @@ rte_mbuf_to_baddr(struct rte_mbuf *md) } /** + * Returns TRUE if given mbuf is cloned by mbuf indirection, or FALSE + * otherwise. + * + * If a mbuf has its data in another mbuf and references it by mbuf + * indirection, this mbuf can be defined as a cloned mbuf. + */ +#define RTE_MBUF_CLONED(mb) ((mb)->ol_flags & IND_ATTACHED_MBUF) + +/** * Returns TRUE if given mbuf is indirect, or FALSE otherwise. */ -#define RTE_MBUF_INDIRECT(mb) ((mb)->ol_flags & IND_ATTACHED_MBUF) +#define RTE_MBUF_INDIRECT(mb) RTE_MBUF_CLONED(mb) + +/** + * Returns TRUE if given mbuf has an external buffer, or FALSE otherwise. + * + * External buffer is a user-provided anonymous buffer. + */ +#define RTE_MBUF_HAS_EXTBUF(mb) ((mb)->ol_flags & EXT_ATTACHED_MBUF) /** * Returns TRUE if given mbuf is direct, or FALSE otherwise. + * + * If a mbuf embeds its own data after the rte_mbuf structure, this mbuf + * can be defined as a direct mbuf. */ -#define RTE_MBUF_DIRECT(mb) (!RTE_MBUF_INDIRECT(mb)) +#define RTE_MBUF_DIRECT(mb) \ + (!((mb)->ol_flags & (IND_ATTACHED_MBUF | EXT_ATTACHED_MBUF))) /** * Private data in case of pktmbuf pool. @@ -840,6 +882,58 @@ rte_mbuf_refcnt_set(struct rte_mbuf *m, uint16_t new_value) #endif /* RTE_MBUF_REFCNT_ATOMIC */ +/** + * Reads the refcnt of an external buffer. + * + * @param shinfo + * Shared data of the external buffer. + * @return + * Reference count number. + */ +static inline uint16_t +rte_mbuf_ext_refcnt_read(const struct rte_mbuf_ext_shared_info *shinfo) +{ + return (uint16_t)(rte_atomic16_read(&shinfo->refcnt_atomic)); +} + +/** + * Set refcnt of an external buffer. + * + * @param shinfo + * Shared data of the external buffer. + * @param new_value + * Value set + */ +static inline void +rte_mbuf_ext_refcnt_set(struct rte_mbuf_ext_shared_info *shinfo, + uint16_t new_value) +{ + rte_atomic16_set(&shinfo->refcnt_atomic, new_value); +} + +/** + * Add given value to refcnt of an external buffer and return its new + * value. + * + * @param shinfo + * Shared data of the external buffer. + * @param value + * Value to add/subtract + * @return + * Updated value + */ +static inline uint16_t +rte_mbuf_ext_refcnt_update(struct rte_mbuf_ext_shared_info *shinfo, + int16_t value) +{ + if (likely(rte_mbuf_ext_refcnt_read(shinfo) == 1)) { + rte_mbuf_ext_refcnt_set(shinfo, 1 + value); + return 1 + value; + } + + return (uint16_t)rte_atomic16_add_return(&shinfo->refcnt_atomic, value); +} + /** Mbuf prefetch */ #define RTE_MBUF_PREFETCH_TO_FREE(m) do { \ if ((m) != NULL) \ @@ -1214,11 +1308,159 @@ static inline int rte_pktmbuf_alloc_bulk(struct rte_mempool *pool, } /** + * Initialize shared data at the end of an external buffer before attaching + * to a mbuf by ``rte_pktmbuf_attach_extbuf()``. This is not a mandatory + * initialization but a helper function to simply spare a few bytes at the + * end of the buffer for shared data. If shared data is allocated + * separately, this should not be called but application has to properly + * initialize the shared data according to its need. + * + * Free callback and its argument is saved and the refcnt is set to 1. + * + * @warning + * The value of buf_len will be reduced to RTE_PTR_DIFF(shinfo, buf_addr) + * after this initialization. This shall be used for + * ``rte_pktmbuf_attach_extbuf()`` + * + * @param buf_addr + * The pointer to the external buffer. + * @param [in,out] buf_len + * The pointer to length of the external buffer. Input value must be + * larger than the size of ``struct rte_mbuf_ext_shared_info`` and + * padding for alignment. If not enough, this function will return NULL. + * Adjusted buffer length will be returned through this pointer. + * @param free_cb + * Free callback function to call when the external buffer needs to be + * freed. + * @param fcb_opaque + * Argument for the free callback function. + * + * @return + * A pointer to the initialized shared data on success, return NULL + * otherwise. + */ +static inline struct rte_mbuf_ext_shared_info * +rte_pktmbuf_ext_shinfo_init_helper(void *buf_addr, uint16_t *buf_len, + rte_mbuf_extbuf_free_callback_t free_cb, void *fcb_opaque) +{ + struct rte_mbuf_ext_shared_info *shinfo; + void *buf_end = RTE_PTR_ADD(buf_addr, *buf_len); + + shinfo = RTE_PTR_ALIGN_FLOOR(RTE_PTR_SUB(buf_end, + sizeof(*shinfo)), sizeof(uintptr_t)); + if ((void *)shinfo <= buf_addr) + return NULL; + + shinfo->free_cb = free_cb; + shinfo->fcb_opaque = fcb_opaque; + rte_mbuf_ext_refcnt_set(shinfo, 1); + + *buf_len = RTE_PTR_DIFF(shinfo, buf_addr); + return shinfo; +} + +/** + * Attach an external buffer to a mbuf. + * + * User-managed anonymous buffer can be attached to an mbuf. When attaching + * it, corresponding free callback function and its argument should be + * provided via shinfo. This callback function will be called once all the + * mbufs are detached from the buffer (refcnt becomes zero). + * + * The headroom for the attaching mbuf will be set to zero and this can be + * properly adjusted after attachment. For example, ``rte_pktmbuf_adj()`` + * or ``rte_pktmbuf_reset_headroom()`` might be used. + * + * More mbufs can be attached to the same external buffer by + * ``rte_pktmbuf_attach()`` once the external buffer has been attached by + * this API. + * + * Detachment can be done by either ``rte_pktmbuf_detach_extbuf()`` or + * ``rte_pktmbuf_detach()``. + * + * Memory for shared data must be provided and user must initialize all of + * the content properly, escpecially free callback and refcnt. The pointer + * of shared data will be stored in m->shinfo. + * ``rte_pktmbuf_ext_shinfo_init_helper`` can help to simply spare a few + * bytes at the end of buffer for the shared data, store free callback and + * its argument and set the refcnt to 1. The following is an example: + * + * struct rte_mbuf_ext_shared_info *shinfo = + * rte_pktmbuf_ext_shinfo_init_helper(buf_addr, &buf_len, + * free_cb, fcb_arg); + * rte_pktmbuf_attach_extbuf(m, buf_addr, buf_iova, buf_len, shinfo); + * rte_pktmbuf_reset_headroom(m); + * rte_pktmbuf_adj(m, data_len); + * + * Attaching an external buffer is quite similar to mbuf indirection in + * replacing buffer addresses and length of a mbuf, but a few differences: + * - When an indirect mbuf is attached, refcnt of the direct mbuf would be + * 2 as long as the direct mbuf itself isn't freed after the attachment. + * In such cases, the buffer area of a direct mbuf must be read-only. But + * external buffer has its own refcnt and it starts from 1. Unless + * multiple mbufs are attached to a mbuf having an external buffer, the + * external buffer is writable. + * - There's no need to allocate buffer from a mempool. Any buffer can be + * attached with appropriate free callback and its IO address. + * - Smaller metadata is required to maintain shared data such as refcnt. + * + * @warning + * @b EXPERIMENTAL: This API may change without prior notice. + * Once external buffer is enabled by allowing experimental API, + * ``RTE_MBUF_DIRECT()`` and ``RTE_MBUF_INDIRECT()`` are no longer + * exclusive. A mbuf can be considered direct if it is neither indirect nor + * having external buffer. + * + * @param m + * The pointer to the mbuf. + * @param buf_addr + * The pointer to the external buffer. + * @param buf_iova + * IO address of the external buffer. + * @param buf_len + * The size of the external buffer. + * @param shinfo + * User-provided memory for shared data of the external buffer. + */ +static inline void __rte_experimental +rte_pktmbuf_attach_extbuf(struct rte_mbuf *m, void *buf_addr, + rte_iova_t buf_iova, uint16_t buf_len, + struct rte_mbuf_ext_shared_info *shinfo) +{ + /* mbuf should not be read-only */ + RTE_ASSERT(RTE_MBUF_DIRECT(m) && rte_mbuf_refcnt_read(m) == 1); + RTE_ASSERT(shinfo->free_cb != NULL); + + m->buf_addr = buf_addr; + m->buf_iova = buf_iova; + m->buf_len = buf_len; + + m->data_len = 0; + m->data_off = 0; + + m->ol_flags |= EXT_ATTACHED_MBUF; + m->shinfo = shinfo; +} + +/** + * Detach the external buffer attached to a mbuf, same as + * ``rte_pktmbuf_detach()`` + * + * @param m + * The mbuf having external buffer. + */ +#define rte_pktmbuf_detach_extbuf(m) rte_pktmbuf_detach(m) + +/** * Attach packet mbuf to another packet mbuf. * - * After attachment we refer the mbuf we attached as 'indirect', - * while mbuf we attached to as 'direct'. - * The direct mbuf's reference counter is incremented. + * If the mbuf we are attaching to isn't a direct buffer and is attached to + * an external buffer, the mbuf being attached will be attached to the + * external buffer instead of mbuf indirection. + * + * Otherwise, the mbuf will be indirectly attached. After attachment we + * refer the mbuf we attached as 'indirect', while mbuf we attached to as + * 'direct'. The direct mbuf's reference counter is incremented. * * Right now, not supported: * - attachment for already indirect mbuf (e.g. - mi has to be direct). @@ -1232,19 +1474,20 @@ static inline int rte_pktmbuf_alloc_bulk(struct rte_mempool *pool, */ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m) { - struct rte_mbuf *md; - RTE_ASSERT(RTE_MBUF_DIRECT(mi) && rte_mbuf_refcnt_read(mi) == 1); - /* if m is not direct, get the mbuf that embeds the data */ - if (RTE_MBUF_DIRECT(m)) - md = m; - else - md = rte_mbuf_from_indirect(m); + if (RTE_MBUF_HAS_EXTBUF(m)) { + rte_mbuf_ext_refcnt_update(m->shinfo, 1); + mi->ol_flags = m->ol_flags; + mi->shinfo = m->shinfo; + } else { + /* if m is not direct, get the mbuf that embeds the data */ + rte_mbuf_refcnt_update(rte_mbuf_from_indirect(m), 1); + mi->priv_size = m->priv_size; + mi->ol_flags = m->ol_flags | IND_ATTACHED_MBUF; + } - rte_mbuf_refcnt_update(md, 1); - mi->priv_size = m->priv_size; mi->buf_iova = m->buf_iova; mi->buf_addr = m->buf_addr; mi->buf_len = m->buf_len; @@ -1260,7 +1503,6 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m) mi->next = NULL; mi->pkt_len = mi->data_len; mi->nb_segs = 1; - mi->ol_flags = m->ol_flags | IND_ATTACHED_MBUF; mi->packet_type = m->packet_type; mi->timestamp = m->timestamp; @@ -1269,12 +1511,52 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m) } /** - * Detach an indirect packet mbuf. + * @internal used by rte_pktmbuf_detach(). * + * Decrement the reference counter of the external buffer. When the + * reference counter becomes 0, the buffer is freed by pre-registered + * callback. + */ +static inline void +__rte_pktmbuf_free_extbuf(struct rte_mbuf *m) +{ + RTE_ASSERT(RTE_MBUF_HAS_EXTBUF(m)); + RTE_ASSERT(m->shinfo != NULL); + + if (rte_mbuf_ext_refcnt_update(m->shinfo, -1) == 0) + m->shinfo->free_cb(m->buf_addr, m->shinfo->fcb_opaque); +} + +/** + * @internal used by rte_pktmbuf_detach(). + * + * Decrement the direct mbuf's reference counter. When the reference + * counter becomes 0, the direct mbuf is freed. + */ +static inline void +__rte_pktmbuf_free_direct(struct rte_mbuf *m) +{ + struct rte_mbuf *md; + + RTE_ASSERT(RTE_MBUF_INDIRECT(m)); + + md = rte_mbuf_from_indirect(m); + + if (rte_mbuf_refcnt_update(md, -1) == 0) { + md->next = NULL; + md->nb_segs = 1; + rte_mbuf_refcnt_set(md, 1); + rte_mbuf_raw_free(md); + } +} + +/** + * Detach a packet mbuf from external buffer or direct buffer. + * + * - decrement refcnt and free the external/direct buffer if refcnt + * becomes zero. * - restore original mbuf address and length values. * - reset pktmbuf data and data_len to their default values. - * - decrement the direct mbuf's reference counter. When the - * reference counter becomes 0, the direct mbuf is freed. * * All other fields of the given packet mbuf will be left intact. * @@ -1283,10 +1565,14 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m) */ static inline void rte_pktmbuf_detach(struct rte_mbuf *m) { - struct rte_mbuf *md = rte_mbuf_from_indirect(m); struct rte_mempool *mp = m->pool; uint32_t mbuf_size, buf_len, priv_size; + if (RTE_MBUF_HAS_EXTBUF(m)) + __rte_pktmbuf_free_extbuf(m); + else + __rte_pktmbuf_free_direct(m); + priv_size = rte_pktmbuf_priv_size(mp); mbuf_size = sizeof(struct rte_mbuf) + priv_size; buf_len = rte_pktmbuf_data_room_size(mp); @@ -1298,13 +1584,6 @@ static inline void rte_pktmbuf_detach(struct rte_mbuf *m) rte_pktmbuf_reset_headroom(m); m->data_len = 0; m->ol_flags = 0; - - if (rte_mbuf_refcnt_update(md, -1) == 0) { - md->next = NULL; - md->nb_segs = 1; - rte_mbuf_refcnt_set(md, 1); - rte_mbuf_raw_free(md); - } } /** @@ -1328,7 +1607,7 @@ rte_pktmbuf_prefree_seg(struct rte_mbuf *m) if (likely(rte_mbuf_refcnt_read(m) == 1)) { - if (RTE_MBUF_INDIRECT(m)) + if (!RTE_MBUF_DIRECT(m)) rte_pktmbuf_detach(m); if (m->next != NULL) { @@ -1340,7 +1619,7 @@ rte_pktmbuf_prefree_seg(struct rte_mbuf *m) } else if (__rte_mbuf_refcnt_update(m, -1) == 0) { - if (RTE_MBUF_INDIRECT(m)) + if (!RTE_MBUF_DIRECT(m)) rte_pktmbuf_detach(m); if (m->next != NULL) { -- 2.11.0