From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH v5 7/9] net/virtio: support in-order Rx and Tx Date: Mon, 2 Jul 2018 17:57:17 +0100 Message-ID: References: <20180702135642.52577-1-yong.liu@intel.com> <20180702135642.52577-8-yong.liu@intel.com> <7ab59556-5719-e05b-ea1f-f94867d90b24@intel.com> <739c4cea-23c8-f1ec-f186-39b74960cb7b@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: zhihong.wang@intel.com, dev@dpdk.org To: Maxime Coquelin , Marvin Liu , tiwei.bie@intel.com Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id CCE071B54A for ; Mon, 2 Jul 2018 18:57:23 +0200 (CEST) In-Reply-To: <739c4cea-23c8-f1ec-f186-39b74960cb7b@redhat.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 7/2/2018 5:53 PM, Maxime Coquelin wrote: > > > On 07/02/2018 06:52 PM, Ferruh Yigit wrote: >> On 7/2/2018 5:41 PM, Ferruh Yigit wrote: >>> On 7/2/2018 2:56 PM, Marvin Liu wrote: >>>> IN_ORDER Rx function depends on merge-able feature. Descriptors >>>> allocation and free will be done in bulk. >>>> >>>> Virtio dequeue logic: >>>> dequeue_burst_rx(burst mbufs) >>>> for (each mbuf b) { >>>> if (b need merge) { >>>> merge remained mbufs >>>> add merged mbuf to return mbufs list >>>> } else { >>>> add mbuf to return mbufs list >>>> } >>>> } >>>> if (last mbuf c need merge) { >>>> dequeue_burst_rx(required mbufs) >>>> merge last mbuf c >>>> } >>>> refill_avail_ring_bulk() >>>> update_avail_ring() >>>> return mbufs list >>>> >>>> IN_ORDER Tx function can support offloading features. Packets which >>>> matched "can_push" option will be handled by simple xmit function. Those >>>> packets can't match "can_push" will be handled by original xmit function >>>> with in-order flag. >>>> >>>> Virtio enqueue logic: >>>> xmit_cleanup(used descs) >>>> for (each xmit mbuf b) { >>>> if (b can inorder xmit) { >>>> add mbuf b to inorder burst list >>>> continue >>>> } else { >>>> xmit inorder burst list >>>> xmit mbuf b by original function >>>> } >>>> } >>>> if (inorder burst list not empty) { >>>> xmit inorder burst list >>>> } >>>> update_avail_ring() >>>> >>>> Signed-off-by: Marvin Liu >>>> Reviewed-by: Maxime Coquelin >>> >>> <...> >>> >>>> @@ -150,6 +188,83 @@ virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num) >>>> } >>>> } >>>> >>>> +/* Cleanup from completed inorder transmits. */ >>>> +static void >>>> +virtio_xmit_cleanup_inorder(struct virtqueue *vq, uint16_t num) >>>> +{ >>>> + uint16_t i, used_idx, desc_idx, last_idx; >>> >>> >>> Getting following build error [1], from code it looks like false positive, but >>> to get rid of the build error would it be OK to set initial value to "desc_idx"? >> >> I applied this while merging, if this is wrong please let me know, we can fix in >> next-net, Thanks. > > Looks good to me. I didn't catch it with the GCC version I use. I didn't dig more but I also didn't get the error with regular build, the one with all DEBUGs enabled and mach=default combination gave the error, not sure why. > > Thanks, > Maxime > >>> >>> >>> [1] >>> .../dpdk/drivers/net/virtio/virtio_rxtx.c:195:24: error: ‘desc_idx’ may be used >>> uninitialized in this function [-Werror=maybe-uninitialized] >>> >>> >>> uint16_t i, used_idx, desc_idx, last_idx; >>> >>> >>> >>> ^~~~~~~~ >>> >>