From 8a1cbedb0b93f4aabae730535a35317cac77043e Mon Sep 17 00:00:00 2001 From: zbb Date: Thu, 31 Mar 2016 13:10:29 +0000 Subject: [PATCH] Improve TX path of the VNIC driver - Avoid memory leak when nicvf_tx_mbuf_locked() fails - Introduce nicvf_xmit_locked() routine that uses drbr_peek(), drbr_advance() or drbr_putback() for a specific ifnet. This gives more clear and efficient design as well as prevents from dropping mbufs that where not sent due to temporary lack of descriptors. - Add missing ETHER_BPF_MTAP() hook Pointed out by: yongari Reviewed by: wma Obtained from: Semihalf Sponsored by: Cavium Differential Revision: https://reviews.freebsd.org/D5534 --- sys/dev/vnic/nicvf_main.c | 17 ++++--- sys/dev/vnic/nicvf_queues.c | 89 ++++++++++++++++++++++++++++--------- sys/dev/vnic/nicvf_queues.h | 2 +- 3 files changed, 78 insertions(+), 30 deletions(-) diff --git a/sys/dev/vnic/nicvf_main.c b/sys/dev/vnic/nicvf_main.c index 4625846fad75..8a33804ddd01 100644 --- a/sys/dev/vnic/nicvf_main.c +++ b/sys/dev/vnic/nicvf_main.c @@ -661,8 +661,8 @@ nicvf_if_transmit(struct ifnet *ifp, struct mbuf *mbuf) sq = &qs->sq[qidx]; - if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) != - IFF_DRV_RUNNING) { + if (((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) != + IFF_DRV_RUNNING) || !nic->link_up) { err = drbr_enqueue(ifp, sq->br, mbuf); return (err); } @@ -679,17 +679,16 @@ nicvf_if_transmit(struct ifnet *ifp, struct mbuf *mbuf) } } + err = drbr_enqueue(ifp, sq->br, mbuf); + if (err != 0) + return (err); + if (NICVF_TX_TRYLOCK(sq) != 0) { - err = nicvf_tx_mbuf_locked(sq, mbuf); + err = nicvf_xmit_locked(sq); NICVF_TX_UNLOCK(sq); return (err); - } else { - err = drbr_enqueue(ifp, sq->br, mbuf); - if (err != 0) - return (err); - + } else taskqueue_enqueue(sq->snd_taskq, &sq->snd_task); - } return (0); } diff --git a/sys/dev/vnic/nicvf_queues.c b/sys/dev/vnic/nicvf_queues.c index 0090796dbcf8..2aeed4de2d77 100644 --- a/sys/dev/vnic/nicvf_queues.c +++ b/sys/dev/vnic/nicvf_queues.c @@ -60,11 +60,12 @@ __FBSDID("$FreeBSD$"); #include #include -#include #include #include #include #include +#include +#include #include #include @@ -105,6 +106,8 @@ static void nicvf_cmp_queue_config(struct nicvf *, struct queue_set *, int, boolean_t); static void nicvf_sq_free_used_descs(struct nicvf *, struct snd_queue *, int); +static int nicvf_tx_mbuf_locked(struct snd_queue *, struct mbuf **); + static void nicvf_rbdr_task(void *, int); static void nicvf_rbdr_task_nowait(void *, int); @@ -739,6 +742,7 @@ nicvf_cq_intr_handler(struct nicvf *nic, uint8_t cq_idx) int cqe_count, cqe_head; struct queue_set *qs = nic->qs; struct cmp_queue *cq = &qs->cq[cq_idx]; + struct snd_queue *sq = &qs->sq[cq_idx]; struct rcv_queue *rq; struct cqe_rx_t *cq_desc; struct lro_ctrl *lro; @@ -818,6 +822,7 @@ nicvf_cq_intr_handler(struct nicvf *nic, uint8_t cq_idx) ((if_getdrvflags(nic->ifp) & IFF_DRV_RUNNING) != 0)) { /* Reenable TXQ if its stopped earlier due to SQ full */ if_setdrvflagbits(nic->ifp, IFF_DRV_RUNNING, IFF_DRV_OACTIVE); + taskqueue_enqueue(sq->snd_taskq, &sq->snd_task); } out: /* @@ -991,25 +996,62 @@ nicvf_free_cmp_queue(struct nicvf *nic, struct cmp_queue *cq) memset(cq->mtx_name, 0, sizeof(cq->mtx_name)); } +int +nicvf_xmit_locked(struct snd_queue *sq) +{ + struct nicvf *nic; + struct ifnet *ifp; + struct mbuf *next; + int err; + + NICVF_TX_LOCK_ASSERT(sq); + + nic = sq->nic; + ifp = nic->ifp; + err = 0; + + while ((next = drbr_peek(ifp, sq->br)) != NULL) { + err = nicvf_tx_mbuf_locked(sq, &next); + if (err != 0) { + if (next == NULL) + drbr_advance(ifp, sq->br); + else + drbr_putback(ifp, sq->br, next); + + break; + } + drbr_advance(ifp, sq->br); + /* Send a copy of the frame to the BPF listener */ + ETHER_BPF_MTAP(ifp, next); + } + return (err); +} + static void nicvf_snd_task(void *arg, int pending) { struct snd_queue *sq = (struct snd_queue *)arg; - struct mbuf *mbuf; + struct nicvf *nic; + struct ifnet *ifp; + int err; + + nic = sq->nic; + ifp = nic->ifp; + + /* + * Skip sending anything if the driver is not running, + * SQ full or link is down. + */ + if (((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) != + IFF_DRV_RUNNING) || !nic->link_up) + return; NICVF_TX_LOCK(sq); - while (1) { - mbuf = drbr_dequeue(NULL, sq->br); - if (mbuf == NULL) - break; - - if (nicvf_tx_mbuf_locked(sq, mbuf) != 0) { - /* XXX ARM64TODO: Increase Tx drop counter */ - m_freem(mbuf); - break; - } - } + err = nicvf_xmit_locked(sq); NICVF_TX_UNLOCK(sq); + /* Try again */ + if (err != 0) + taskqueue_enqueue(sq->snd_taskq, &sq->snd_task); } /* Initialize transmit queue */ @@ -1862,8 +1904,8 @@ static inline void nicvf_sq_add_gather_subdesc(struct snd_queue *sq, int qentry, } /* Put an mbuf to a SQ for packet transfer. */ -int -nicvf_tx_mbuf_locked(struct snd_queue *sq, struct mbuf *mbuf) +static int +nicvf_tx_mbuf_locked(struct snd_queue *sq, struct mbuf **mbufp) { bus_dma_segment_t segs[256]; struct nicvf *nic; @@ -1881,15 +1923,17 @@ nicvf_tx_mbuf_locked(struct snd_queue *sq, struct mbuf *mbuf) snd_buff = &sq->snd_buff[sq->tail]; err = bus_dmamap_load_mbuf_sg(sq->snd_buff_dmat, snd_buff->dmap, - mbuf, segs, &nsegs, BUS_DMA_NOWAIT); - if (err != 0) { + *mbufp, segs, &nsegs, BUS_DMA_NOWAIT); + if (__predict_false(err != 0)) { /* ARM64TODO: Add mbuf defragmenting if we lack maps */ + m_freem(*mbufp); + *mbufp = NULL; return (err); } /* Set how many subdescriptors is required */ nic = sq->nic; - if (mbuf->m_pkthdr.tso_segsz != 0 && nic->hw_tso) + if ((*mbufp)->m_pkthdr.tso_segsz != 0 && nic->hw_tso) subdesc_cnt = MIN_SQ_DESC_PER_PKT_XMIT; else subdesc_cnt = MIN_SQ_DESC_PER_PKT_XMIT + nsegs - 1; @@ -1903,10 +1947,15 @@ nicvf_tx_mbuf_locked(struct snd_queue *sq, struct mbuf *mbuf) qentry = nicvf_get_sq_desc(sq, subdesc_cnt); /* Add SQ header subdesc */ - err = nicvf_sq_add_hdr_subdesc(sq, qentry, subdesc_cnt - 1, mbuf, - mbuf->m_pkthdr.len); + err = nicvf_sq_add_hdr_subdesc(sq, qentry, subdesc_cnt - 1, *mbufp, + (*mbufp)->m_pkthdr.len); if (err != 0) { + nicvf_put_sq_desc(sq, subdesc_cnt); bus_dmamap_unload(sq->snd_buff_dmat, snd_buff->dmap); + if (err == ENOBUFS) { + m_freem(*mbufp); + *mbufp = NULL; + } return (err); } diff --git a/sys/dev/vnic/nicvf_queues.h b/sys/dev/vnic/nicvf_queues.h index 8a27880e0418..0fe8e3b88e05 100644 --- a/sys/dev/vnic/nicvf_queues.h +++ b/sys/dev/vnic/nicvf_queues.h @@ -388,7 +388,7 @@ void nicvf_disable_intr(struct nicvf *, int, int); void nicvf_clear_intr(struct nicvf *, int, int); int nicvf_is_intr_enabled(struct nicvf *, int, int); -int nicvf_tx_mbuf_locked(struct snd_queue *, struct mbuf *); +int nicvf_xmit_locked(struct snd_queue *sq); /* Register access APIs */ void nicvf_reg_write(struct nicvf *, uint64_t, uint64_t);