From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id E59C811A4 for ; Tue, 19 Mar 2019 10:37:50 +0100 (CET) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Mar 2019 02:37:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,497,1544515200"; d="scan'208";a="308437382" Received: from dpdk-tbie.sh.intel.com ([10.67.104.173]) by orsmga005.jf.intel.com with ESMTP; 19 Mar 2019 02:37:48 -0700 Date: Tue, 19 Mar 2019 17:37:34 +0800 From: Tiwei Bie To: Jens Freimann Cc: maxime.coquelin@redhat.com, zhihong.wang@intel.com, dev@dpdk.org Message-ID: <20190319093734.GA24818@dpdk-tbie.sh.intel.com> References: <20190319064312.13743-1-tiwei.bie@intel.com> <20190319064312.13743-5-tiwei.bie@intel.com> <20190319085403.gnamedd5pz7jzwvj@jenstp.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190319085403.gnamedd5pz7jzwvj@jenstp.localdomain> User-Agent: Mutt/1.9.4 (2018-02-28) Subject: Re: [dpdk-dev] [PATCH 04/10] net/virtio: optimize flags update for packed ring X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Mar 2019 09:37:51 -0000 On Tue, Mar 19, 2019 at 09:54:03AM +0100, Jens Freimann wrote: > On Tue, Mar 19, 2019 at 02:43:06PM +0800, Tiwei Bie wrote: > > Cache the AVAIL, USED and WRITE bits to avoid calculating > > them as much as possible. Note that, the WRITE bit isn't > > cached for control queue. > > > > Signed-off-by: Tiwei Bie > > --- > > drivers/net/virtio/virtio_ethdev.c | 35 ++++++++++++++---------------- > > drivers/net/virtio/virtio_rxtx.c | 31 ++++++++++---------------- > > drivers/net/virtio/virtqueue.h | 8 +++---- > > 3 files changed, 32 insertions(+), 42 deletions(-) > > > > diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c > > index ff16fb63e..9060b6b33 100644 > > --- a/drivers/net/virtio/virtio_ethdev.c > > +++ b/drivers/net/virtio/virtio_ethdev.c > > @@ -149,7 +149,7 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > int head; > > struct vring_packed_desc *desc = vq->ring_packed.desc_packed; > > struct virtio_pmd_ctrl *result; > > - bool avail_wrap_counter; > > + uint16_t flags; > > int sum = 0; > > int nb_descs = 0; > > int k; > > @@ -161,14 +161,15 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > * One RX packet for ACK. > > */ > > head = vq->vq_avail_idx; > > - avail_wrap_counter = vq->avail_wrap_counter; > > + flags = vq->cached_flags; > > desc[head].addr = cvq->virtio_net_hdr_mem; > > desc[head].len = sizeof(struct virtio_net_ctrl_hdr); > > vq->vq_free_cnt--; > > nb_descs++; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > Maybe name it avail_used_flags instead of cached flags. Also we could > use a constant value. It also contains the WRITE bit (not just AVAIL and USED bits) for Rx path. That's why I didn't name it as avail_used_flags. > > > } > > > > for (k = 0; k < pkt_num; k++) { > > @@ -177,34 +178,31 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > + sizeof(ctrl->status) + sizeof(uint8_t) * sum; > > desc[vq->vq_avail_idx].len = dlen[k]; > > desc[vq->vq_avail_idx].flags = VRING_DESC_F_NEXT | > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > + vq->cached_flags; > > sum += dlen[k]; > > vq->vq_free_cnt--; > > nb_descs++; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > } > > } > > > > desc[vq->vq_avail_idx].addr = cvq->virtio_net_hdr_mem > > + sizeof(struct virtio_net_ctrl_hdr); > > desc[vq->vq_avail_idx].len = sizeof(ctrl->status); > > - desc[vq->vq_avail_idx].flags = VRING_DESC_F_WRITE | > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > + desc[vq->vq_avail_idx].flags = VRING_DESC_F_WRITE | vq->cached_flags; > > vq->vq_free_cnt--; > > nb_descs++; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > } > > > > virtio_wmb(vq->hw->weak_barriers); > > - desc[head].flags = VRING_DESC_F_NEXT | > > - VRING_DESC_F_AVAIL(avail_wrap_counter) | > > - VRING_DESC_F_USED(!avail_wrap_counter); > > + desc[head].flags = VRING_DESC_F_NEXT | flags; > > > > virtio_wmb(vq->hw->weak_barriers); > > virtqueue_notify(vq); > > @@ -226,12 +224,12 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > PMD_INIT_LOG(DEBUG, "vq->vq_free_cnt=%d\n" > > "vq->vq_avail_idx=%d\n" > > "vq->vq_used_cons_idx=%d\n" > > - "vq->avail_wrap_counter=%d\n" > > + "vq->cached_flags=0x%x\n" > > "vq->used_wrap_counter=%d\n", > > vq->vq_free_cnt, > > vq->vq_avail_idx, > > vq->vq_used_cons_idx, > > - vq->avail_wrap_counter, > > + vq->cached_flags, > > vq->used_wrap_counter); > > > > result = cvq->virtio_net_hdr_mz->addr; > > @@ -491,11 +489,10 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx) > > vq->vq_nentries = vq_size; > > vq->event_flags_shadow = 0; > > if (vtpci_packed_queue(hw)) { > > - vq->avail_wrap_counter = 1; > > vq->used_wrap_counter = 1; > > - vq->avail_used_flags = > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > + vq->cached_flags = VRING_DESC_F_AVAIL(1); > > + if (queue_type == VTNET_RQ) > > + vq->cached_flags |= VRING_DESC_F_WRITE; > > } > > > > /* > > diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c > > index 771d3c3f6..3c354baef 100644 > > --- a/drivers/net/virtio/virtio_rxtx.c > > +++ b/drivers/net/virtio/virtio_rxtx.c > > @@ -431,7 +431,7 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq, > > struct rte_mbuf **cookie, uint16_t num) > > { > > struct vring_packed_desc *start_dp = vq->ring_packed.desc_packed; > > - uint16_t flags = VRING_DESC_F_WRITE | vq->avail_used_flags; > > + uint16_t flags = vq->cached_flags; > > struct virtio_hw *hw = vq->hw; > > struct vq_desc_extra *dxp; > > uint16_t idx; > > @@ -460,11 +460,9 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq, > > start_dp[idx].flags = flags; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > - vq->avail_used_flags = > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > - flags = VRING_DESC_F_WRITE | vq->avail_used_flags; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > + flags = vq->cached_flags; > > same here. it's not really cached, it's pre-calculated. And here we > could also use a pre-calculated constand/define. For pre-calculated constant/define, do you mean VRING_DESC_F_AVAIL(1) and VRING_DESC_F_USED(1)? There is still little code in virtio-user using them without constantly passing 1. I planned to fully get rid of them in a separate patch later (but I can do it in this series if anyone wants). > > Otherwise looks good! Did you see any performance improvements? Yeah, I saw slightly better performance in a quick test. Thanks, Tiwei > > > regards, > Jens From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 105DBA00E6 for ; Tue, 19 Mar 2019 10:37:54 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id D547A1DBD; Tue, 19 Mar 2019 10:37:52 +0100 (CET) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id E59C811A4 for ; Tue, 19 Mar 2019 10:37:50 +0100 (CET) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Mar 2019 02:37:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,497,1544515200"; d="scan'208";a="308437382" Received: from dpdk-tbie.sh.intel.com ([10.67.104.173]) by orsmga005.jf.intel.com with ESMTP; 19 Mar 2019 02:37:48 -0700 Date: Tue, 19 Mar 2019 17:37:34 +0800 From: Tiwei Bie To: Jens Freimann Cc: maxime.coquelin@redhat.com, zhihong.wang@intel.com, dev@dpdk.org Message-ID: <20190319093734.GA24818@dpdk-tbie.sh.intel.com> References: <20190319064312.13743-1-tiwei.bie@intel.com> <20190319064312.13743-5-tiwei.bie@intel.com> <20190319085403.gnamedd5pz7jzwvj@jenstp.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <20190319085403.gnamedd5pz7jzwvj@jenstp.localdomain> User-Agent: Mutt/1.9.4 (2018-02-28) Subject: Re: [dpdk-dev] [PATCH 04/10] net/virtio: optimize flags update for packed ring X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Message-ID: <20190319093734.NeQoDtE9CabHd01KoWRRTP3GS1D3z9UbyhCemkdjD9M@z> On Tue, Mar 19, 2019 at 09:54:03AM +0100, Jens Freimann wrote: > On Tue, Mar 19, 2019 at 02:43:06PM +0800, Tiwei Bie wrote: > > Cache the AVAIL, USED and WRITE bits to avoid calculating > > them as much as possible. Note that, the WRITE bit isn't > > cached for control queue. > > > > Signed-off-by: Tiwei Bie > > --- > > drivers/net/virtio/virtio_ethdev.c | 35 ++++++++++++++---------------- > > drivers/net/virtio/virtio_rxtx.c | 31 ++++++++++---------------- > > drivers/net/virtio/virtqueue.h | 8 +++---- > > 3 files changed, 32 insertions(+), 42 deletions(-) > > > > diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c > > index ff16fb63e..9060b6b33 100644 > > --- a/drivers/net/virtio/virtio_ethdev.c > > +++ b/drivers/net/virtio/virtio_ethdev.c > > @@ -149,7 +149,7 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > int head; > > struct vring_packed_desc *desc = vq->ring_packed.desc_packed; > > struct virtio_pmd_ctrl *result; > > - bool avail_wrap_counter; > > + uint16_t flags; > > int sum = 0; > > int nb_descs = 0; > > int k; > > @@ -161,14 +161,15 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > * One RX packet for ACK. > > */ > > head = vq->vq_avail_idx; > > - avail_wrap_counter = vq->avail_wrap_counter; > > + flags = vq->cached_flags; > > desc[head].addr = cvq->virtio_net_hdr_mem; > > desc[head].len = sizeof(struct virtio_net_ctrl_hdr); > > vq->vq_free_cnt--; > > nb_descs++; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > Maybe name it avail_used_flags instead of cached flags. Also we could > use a constant value. It also contains the WRITE bit (not just AVAIL and USED bits) for Rx path. That's why I didn't name it as avail_used_flags. > > > } > > > > for (k = 0; k < pkt_num; k++) { > > @@ -177,34 +178,31 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > + sizeof(ctrl->status) + sizeof(uint8_t) * sum; > > desc[vq->vq_avail_idx].len = dlen[k]; > > desc[vq->vq_avail_idx].flags = VRING_DESC_F_NEXT | > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > + vq->cached_flags; > > sum += dlen[k]; > > vq->vq_free_cnt--; > > nb_descs++; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > } > > } > > > > desc[vq->vq_avail_idx].addr = cvq->virtio_net_hdr_mem > > + sizeof(struct virtio_net_ctrl_hdr); > > desc[vq->vq_avail_idx].len = sizeof(ctrl->status); > > - desc[vq->vq_avail_idx].flags = VRING_DESC_F_WRITE | > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > + desc[vq->vq_avail_idx].flags = VRING_DESC_F_WRITE | vq->cached_flags; > > vq->vq_free_cnt--; > > nb_descs++; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > } > > > > virtio_wmb(vq->hw->weak_barriers); > > - desc[head].flags = VRING_DESC_F_NEXT | > > - VRING_DESC_F_AVAIL(avail_wrap_counter) | > > - VRING_DESC_F_USED(!avail_wrap_counter); > > + desc[head].flags = VRING_DESC_F_NEXT | flags; > > > > virtio_wmb(vq->hw->weak_barriers); > > virtqueue_notify(vq); > > @@ -226,12 +224,12 @@ virtio_send_command_packed(struct virtnet_ctl *cvq, > > PMD_INIT_LOG(DEBUG, "vq->vq_free_cnt=%d\n" > > "vq->vq_avail_idx=%d\n" > > "vq->vq_used_cons_idx=%d\n" > > - "vq->avail_wrap_counter=%d\n" > > + "vq->cached_flags=0x%x\n" > > "vq->used_wrap_counter=%d\n", > > vq->vq_free_cnt, > > vq->vq_avail_idx, > > vq->vq_used_cons_idx, > > - vq->avail_wrap_counter, > > + vq->cached_flags, > > vq->used_wrap_counter); > > > > result = cvq->virtio_net_hdr_mz->addr; > > @@ -491,11 +489,10 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx) > > vq->vq_nentries = vq_size; > > vq->event_flags_shadow = 0; > > if (vtpci_packed_queue(hw)) { > > - vq->avail_wrap_counter = 1; > > vq->used_wrap_counter = 1; > > - vq->avail_used_flags = > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > + vq->cached_flags = VRING_DESC_F_AVAIL(1); > > + if (queue_type == VTNET_RQ) > > + vq->cached_flags |= VRING_DESC_F_WRITE; > > } > > > > /* > > diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c > > index 771d3c3f6..3c354baef 100644 > > --- a/drivers/net/virtio/virtio_rxtx.c > > +++ b/drivers/net/virtio/virtio_rxtx.c > > @@ -431,7 +431,7 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq, > > struct rte_mbuf **cookie, uint16_t num) > > { > > struct vring_packed_desc *start_dp = vq->ring_packed.desc_packed; > > - uint16_t flags = VRING_DESC_F_WRITE | vq->avail_used_flags; > > + uint16_t flags = vq->cached_flags; > > struct virtio_hw *hw = vq->hw; > > struct vq_desc_extra *dxp; > > uint16_t idx; > > @@ -460,11 +460,9 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq, > > start_dp[idx].flags = flags; > > if (++vq->vq_avail_idx >= vq->vq_nentries) { > > vq->vq_avail_idx -= vq->vq_nentries; > > - vq->avail_wrap_counter ^= 1; > > - vq->avail_used_flags = > > - VRING_DESC_F_AVAIL(vq->avail_wrap_counter) | > > - VRING_DESC_F_USED(!vq->avail_wrap_counter); > > - flags = VRING_DESC_F_WRITE | vq->avail_used_flags; > > + vq->cached_flags ^= > > + VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1); > > + flags = vq->cached_flags; > > same here. it's not really cached, it's pre-calculated. And here we > could also use a pre-calculated constand/define. For pre-calculated constant/define, do you mean VRING_DESC_F_AVAIL(1) and VRING_DESC_F_USED(1)? There is still little code in virtio-user using them without constantly passing 1. I planned to fully get rid of them in a separate patch later (but I can do it in this series if anyone wants). > > Otherwise looks good! Did you see any performance improvements? Yeah, I saw slightly better performance in a quick test. Thanks, Tiwei > > > regards, > Jens