Author: sephe Date: Tue Nov 1 08:20:33 2016 New Revision: 308167 URL: https://svnweb.freebsd.org/changeset/base/308167
Log: hyperv/hn: Directly fill chimney sending buffer for small packets. MFC after: 1 week Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D8394 Modified: head/sys/dev/hyperv/netvsc/if_hn.c Modified: head/sys/dev/hyperv/netvsc/if_hn.c ============================================================================== --- head/sys/dev/hyperv/netvsc/if_hn.c Tue Nov 1 07:41:26 2016 (r308166) +++ head/sys/dev/hyperv/netvsc/if_hn.c Tue Nov 1 08:20:33 2016 (r308167) @@ -1394,15 +1394,28 @@ hn_encap(struct hn_tx_ring *txr, struct struct mbuf *m_head = *m_head0; struct rndis_packet_msg *pkt; uint32_t *pi_data; + void *chim = NULL; int pktlen; - /* - * extension points to the area reserved for the - * rndis_filter_packet, which is placed just after - * the netvsc_packet (and rppi struct, if present; - * length is updated later). - */ pkt = txd->rndis_pkt; + if (m_head->m_pkthdr.len + HN_RNDIS_PKT_LEN < txr->hn_chim_size) { + /* + * This packet is small enough to fit into a chimney sending + * buffer. Try allocating one chimney sending buffer now. + */ + txr->hn_tx_chimney_tried++; + txd->chim_index = hn_chim_alloc(txr->hn_sc); + if (txd->chim_index != HN_NVS_CHIM_IDX_INVALID) { + chim = txr->hn_sc->hn_chim + + (txd->chim_index * txr->hn_sc->hn_chim_szmax); + /* + * Directly fill the chimney sending buffer w/ the + * RNDIS packet message. + */ + pkt = chim; + } + } + pkt->rm_type = REMOTE_NDIS_PACKET_MSG; pkt->rm_len = sizeof(*pkt) + m_head->m_pkthdr.len; pkt->rm_dataoffset = sizeof(*pkt); @@ -1475,26 +1488,25 @@ hn_encap(struct hn_tx_ring *txr, struct pkt->rm_pktinfooffset = hn_rndis_pktmsg_offset(pkt->rm_pktinfooffset); /* - * Chimney send, if the packet could fit into one chimney buffer. + * Fast path: Chimney sending. */ - if (pkt->rm_len < txr->hn_chim_size) { - txr->hn_tx_chimney_tried++; - txd->chim_index = hn_chim_alloc(txr->hn_sc); - if (txd->chim_index != HN_NVS_CHIM_IDX_INVALID) { - uint8_t *dest = txr->hn_sc->hn_chim + - (txd->chim_index * txr->hn_sc->hn_chim_szmax); - - memcpy(dest, pkt, pktlen); - dest += pktlen; - m_copydata(m_head, 0, m_head->m_pkthdr.len, dest); - - txd->chim_size = pkt->rm_len; - txr->hn_gpa_cnt = 0; - txr->hn_tx_chimney++; - txr->hn_sendpkt = hn_txpkt_chim; - goto done; - } - } + if (chim != NULL) { + KASSERT(txd->chim_index != HN_NVS_CHIM_IDX_INVALID, + ("chimney buffer is not used")); + KASSERT(pkt == chim, ("RNDIS pkt not in chimney buffer")); + + m_copydata(m_head, 0, m_head->m_pkthdr.len, + ((uint8_t *)chim) + pktlen); + + txd->chim_size = pkt->rm_len; + txr->hn_gpa_cnt = 0; + txr->hn_tx_chimney++; + txr->hn_sendpkt = hn_txpkt_chim; + goto done; + } + KASSERT(txd->chim_index == HN_NVS_CHIM_IDX_INVALID, + ("chimney buffer is used")); + KASSERT(pkt == txd->rndis_pkt, ("RNDIS pkt not in txdesc")); error = hn_txdesc_dmamap_load(txr, txd, &m_head, segs, &nsegs); if (error) { _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
