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From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Joyce Kong <joyce.kong@arm.com>,
	chenbo.xia@intel.com, jerinj@marvell.com, ruifeng.wang@arm.com,
	honnappa.nagarahalli@arm.com
Cc: dev@dpdk.org, nd@arm.com
Subject: Re: [dpdk-dev] [PATCH v1 2/4] net/virtio: add vectorized packed ring Rx NEON path
Date: Thu, 7 Jan 2021 11:39:39 +0100
Message-ID: <f7818991-5bf2-8ca3-8230-cbd47a8c7718@redhat.com> (raw)
In-Reply-To: <1473dd81-26aa-04ae-dd57-14ddf7880fd0@redhat.com>



On 1/5/21 3:27 PM, Maxime Coquelin wrote:
> 
> 
> On 1/5/21 3:16 PM, Maxime Coquelin wrote:
>>
>>
>> On 11/17/20 11:06 AM, Joyce Kong wrote:
>>> Optimize packed ring Rx batch path with NEON instructions.
>>>
>>> Signed-off-by: Joyce Kong <joyce.kong@arm.com>
>>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
>>> ---
>>>  drivers/net/virtio/virtio_rxtx_packed.h      |  15 ++
>>>  drivers/net/virtio/virtio_rxtx_packed_neon.h | 150 +++++++++++++++++++
>>>  2 files changed, 165 insertions(+)
>>>  create mode 100644 drivers/net/virtio/virtio_rxtx_packed_neon.h
>>>
>>> diff --git a/drivers/net/virtio/virtio_rxtx_packed.h b/drivers/net/virtio/virtio_rxtx_packed.h
>>> index b0b1d63ec..8f5198ad7 100644
>>> --- a/drivers/net/virtio/virtio_rxtx_packed.h
>>> +++ b/drivers/net/virtio/virtio_rxtx_packed.h
>>> @@ -19,9 +19,16 @@
>>>  #include "virtqueue.h"
>>>  
>>>  #define BYTE_SIZE 8
>>> +
>>> +#ifdef CC_AVX512_SUPPORT
>>>  /* flag bits offset in packed ring desc higher 64bits */
>>>  #define FLAGS_BITS_OFFSET ((offsetof(struct vring_packed_desc, flags) - \
>>>  	offsetof(struct vring_packed_desc, len)) * BYTE_SIZE)
>>> +#elif defined(RTE_ARCH_ARM)
>>> +/* flag bits offset in packed ring desc from ID */
>>> +#define FLAGS_BITS_OFFSET ((offsetof(struct vring_packed_desc, flags) - \
>>> +	offsetof(struct vring_packed_desc, id)) * BYTE_SIZE)
>>> +#endif
>>>  
>>>  #define PACKED_FLAGS_MASK ((0ULL | VRING_PACKED_DESC_F_AVAIL_USED) << \
>>>  	FLAGS_BITS_OFFSET)
>>> @@ -44,8 +51,16 @@
>>>  /* net hdr short size mask */
>>>  #define NET_HDR_MASK 0x3F
>>>  
>>> +#ifdef RTE_ARCH_ARM
>>> +/* The cache line size on different Arm platforms are different, so
>>> + * put a four batch size here to match with the minimum cache line
>>> + * size and accommodate NEON register size.
>>> + */
>>> +#define PACKED_BATCH_SIZE 4
>>> +#else
>>>  #define PACKED_BATCH_SIZE (RTE_CACHE_LINE_SIZE / \
>>>  	sizeof(struct vring_packed_desc))
>>> +#endif
>>>  #define PACKED_BATCH_MASK (PACKED_BATCH_SIZE - 1)
>>>  
>>>  #ifdef VIRTIO_GCC_UNROLL_PRAGMA
>>> diff --git a/drivers/net/virtio/virtio_rxtx_packed_neon.h b/drivers/net/virtio/virtio_rxtx_packed_neon.h
>>> new file mode 100644
>>> index 000000000..fb1e49909
>>> --- /dev/null
>>> +++ b/drivers/net/virtio/virtio_rxtx_packed_neon.h
>>> @@ -0,0 +1,150 @@
>>> +/* SPDX-License-Identifier: BSD-3-Clause
>>> + * Copyright(c) 2020 Arm Corporation
>>> + */
>>> +
>>> +#include <stdlib.h>
>>> +#include <stdint.h>
>>> +#include <stdio.h>
>>> +#include <string.h>
>>> +#include <errno.h>
>>> +
>>> +#include <rte_net.h>
>>> +#include <rte_vect.h>
>>> +
>>> +#include "virtio_ethdev.h"
>>> +#include "virtio_pci.h"
>>> +#include "virtio_rxtx_packed.h"
>>> +#include "virtqueue.h"
>>> +
>>> +static inline uint16_t
>>> +virtqueue_dequeue_batch_packed_vec(struct virtnet_rx *rxvq,
>>> +				   struct rte_mbuf **rx_pkts)
>>> +{
>>> +	struct virtqueue *vq = rxvq->vq;
>>> +	struct virtio_hw *hw = vq->hw;
>>> +	uint16_t head_size = hw->vtnet_hdr_size;
>>> +	uint16_t id = vq->vq_used_cons_idx;
>>> +	struct vring_packed_desc *p_desc;
>>> +	uint16_t i;
>>> +
>>> +	if (id & PACKED_BATCH_MASK)
>>> +		return -1;
>>> +
>>> +	if (unlikely((id + PACKED_BATCH_SIZE) > vq->vq_nentries))
>>> +		return -1;
>>
>> This function returns an unsigned short, I think you should return 0
>> here since it failed to dequeue packets.
>>
>>> +	/* Map packed descriptor to mbuf fields. */
>>> +	uint8x16_t shuf_msk1 = {
>>> +		0xFF, 0xFF, 0xFF, 0xFF, /* pkt_type set as unknown */
>>> +		0, 1,			/* octet 1~0, low 16 bits pkt_len */
>>> +		0xFF, 0xFF,		/* skip high 16 bits of pkt_len, zero out */
>>> +		0, 1,			/* octet 1~0, 16 bits data_len */
>>> +		0xFF, 0xFF,		/* vlan tci set as unknown */
>>> +		0xFF, 0xFF, 0xFF, 0xFF
>>> +	};
>>> +
>>> +	uint8x16_t shuf_msk2 = {
>>> +		0xFF, 0xFF, 0xFF, 0xFF, /* pkt_type set as unknown */
>>> +		8, 9,			/* octet 9~8, low 16 bits pkt_len */
>>> +		0xFF, 0xFF,		/* skip high 16 bits of pkt_len, zero out */
>>> +		8, 9,			/* octet 9~8, 16 bits data_len */
>>> +		0xFF, 0xFF,		/* vlan tci set as unknown */
>>> +		0xFF, 0xFF, 0xFF, 0xFF
>>> +	};
>>> +
>>> +	/* Subtract the header length. */
>>> +	uint16x8_t len_adjust = {
>>> +		0, 0,		/* ignore pkt_type field */
>>> +		head_size,	/* sub head_size on pkt_len */
>>> +		0,		/* ignore high 16 bits of pkt_len */
>>> +		head_size,	/* sub head_size on data_len */
>>> +		0, 0, 0		/* ignore non-length fields */
>>> +	};
>>> +
>>> +	uint64x2_t desc[PACKED_BATCH_SIZE / 2];
>>> +	uint64x2x2_t mbp[PACKED_BATCH_SIZE / 2];
>>> +	uint64x2_t pkt_mb[PACKED_BATCH_SIZE];
>>> +
>>> +	p_desc = &vq->vq_packed.ring.desc[id];
>>> +	/* Load high 64 bits of packed descriptor 0,1. */
>>> +	desc[0] = vld2q_u64((uint64_t *)(p_desc)).val[1];
>>> +	/* Load high 64 bits of packed descriptor 2,3. */
>>> +	desc[1] = vld2q_u64((uint64_t *)(p_desc + 2)).val[1];
>>> +
>>> +	/* Only care avail/used bits. */
>>> +	uint32x4_t v_mask = vdupq_n_u32(PACKED_FLAGS_MASK);
>>> +	/* Extract high 32 bits of packed descriptor (id, flags). */
>>> +	uint32x4_t v_desc = vuzp2q_u32(vreinterpretq_u32_u64(desc[0]),
>>> +				vreinterpretq_u32_u64(desc[1]));
>>> +	uint32x4_t v_flag = vandq_u32(v_desc, v_mask);
>>> +
>>> +	uint32x4_t v_used_flag = vdupq_n_u32(0);
>>> +	if (vq->vq_packed.used_wrap_counter)
>>> +		v_used_flag = vdupq_n_u32(PACKED_FLAGS_MASK);
>>> +
>>> +	poly128_t desc_stats = vreinterpretq_p128_u32(~vceqq_u32(v_flag, v_used_flag));
>>> +
>>> +	/* Check all descs are used. */
>>> +	if (desc_stats)
>>> +		return -1;
>>
>> Same here. You should return 0 here as the queue is full.
> 
> Just looked again at the code and at AVX implementation.
> It should not return 0 here, but any positive value.
> 
> Maybe the cleanest way would change the function prototype to int.
> 0: success
> -1: failure


Joyce, are you fine if I do the cange while applying?
I have a big series that will conflicts with your patch set, so I'd like
to have yours merged ASAP so I can start the rebase.

Thanks,
Maxime

>>> +
>>> +	/* Load 2 mbuf pointers per time. */
>>> +	mbp[0] = vld2q_u64((uint64_t *)&vq->vq_descx[id]);
>>> +	vst1q_u64((uint64_t *)&rx_pkts[0], mbp[0].val[0]);
>>> +
>>> +	mbp[1] = vld2q_u64((uint64_t *)&vq->vq_descx[id + 2]);
>>> +	vst1q_u64((uint64_t *)&rx_pkts[2], mbp[1].val[0]);
>>> +
>>> +	/**
>>> +	 *  Update data length and packet length for descriptor.
>>> +	 *  structure of pkt_mb:
>>> +	 *  --------------------------------------------------------------------
>>> +	 *  |32 bits pkt_type|32 bits pkt_len|16 bits data_len|16 bits vlan_tci|
>>> +	 *  --------------------------------------------------------------------
>>> +	 */
>>> +	pkt_mb[0] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>> +			vreinterpretq_u8_u64(desc[0]), shuf_msk1));
>>> +	pkt_mb[1] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>> +			vreinterpretq_u8_u64(desc[0]), shuf_msk2));
>>> +	pkt_mb[2] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>> +			vreinterpretq_u8_u64(desc[1]), shuf_msk1))'
>>> +	pkt_mb[3] = vreinterpretq_u64_u8(vqtbl1q_u8(
>>> +			vreinterpretq_u8_u64(desc[1]), shuf_msk2));
>>> +
>>> +	pkt_mb[0] = vreinterpretq_u64_u16(vsubq_u16(
>>> +			vreinterpretq_u16_u64(pkt_mb[0]), len_adjust));
>>> +	pkt_mb[1] = vreinterpretq_u64_u16(vsubq_u16(
>>> +			vreinterpretq_u16_u64(pkt_mb[1]), len_adjust));
>>> +	pkt_mb[2] = vreinterpretq_u64_u16(vsubq_u16(
>>> +			vreinterpretq_u16_u64(pkt_mb[2]), len_adjust));
>>> +	pkt_mb[3] = vreinterpretq_u64_u16(vsubq_u16(
>>> +			vreinterpretq_u16_u64(pkt_mb[3]), len_adjust));
>>> +
>>> +	vst1q_u64((void *)&rx_pkts[0]->rx_descriptor_fields1, pkt_mb[0]);
>>> +	vst1q_u64((void *)&rx_pkts[1]->rx_descriptor_fields1, pkt_mb[1]);
>>> +	vst1q_u64((void *)&rx_pkts[2]->rx_descriptor_fields1, pkt_mb[2]);
>>> +	vst1q_u64((void *)&rx_pkts[3]->rx_descriptor_fields1, pkt_mb[3]);
>>> +
>>> +	if (hw->has_rx_offload) {
>>> +		virtio_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
>>> +			char *addr = (char *)rx_pkts[i]->buf_addr +
>>> +				RTE_PKTMBUF_HEADROOM - head_size;
>>> +			virtio_vec_rx_offload(rx_pkts[i],
>>> +					(struct virtio_net_hdr *)addr);
>>> +		}
>>> +	}
>>> +
>>> +	virtio_update_batch_stats(&rxvq->stats, rx_pkts[0]->pkt_len,
>>> +			rx_pkts[1]->pkt_len, rx_pkts[2]->pkt_len,
>>> +			rx_pkts[3]->pkt_len);
>>> +
>>> +	vq->vq_free_cnt += PACKED_BATCH_SIZE;
>>> +
>>> +	vq->vq_used_cons_idx += PACKED_BATCH_SIZE;
>>> +	if (vq->vq_used_cons_idx >= vq->vq_nentries) {
>>> +		vq->vq_used_cons_idx -= vq->vq_nentries;
>>> +		vq->vq_packed.used_wrap_counter ^= 1;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>>
>>


  reply	other threads:[~2021-01-07 10:39 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-11 12:09 [dpdk-dev] [RFC 0/3] Vectorize packed ring RX path with NEON Joyce Kong
2020-09-11 12:09 ` [dpdk-dev] [RFC 1/3] net/virtio: move AVX based Rx and Tx code to separate file Joyce Kong
2020-09-11 12:09 ` [dpdk-dev] [RFC 2/3] net/virtio: add vectorized packed ring Rx NEON path Joyce Kong
2020-09-11 12:09 ` [dpdk-dev] [RFC 3/3] net/virtio: add election for packed vector " Joyce Kong
2020-10-05  7:34 ` [dpdk-dev] [RFC 0/3] Vectorize packed ring RX path with NEON Maxime Coquelin
2020-10-08  6:54   ` Joyce Kong
2020-10-15  9:01   ` Ruifeng Wang
2020-10-15  9:02     ` Maxime Coquelin
2020-11-17 10:06 ` [dpdk-dev] [PATCH v1 0/4] Vectorize packed ring RX/TX " Joyce Kong
2020-11-17 10:06   ` [dpdk-dev] [PATCH v1 1/4] net/virtio: move AVX based Rx and Tx code to separate file Joyce Kong
2021-01-05 14:06     ` Maxime Coquelin
2020-11-17 10:06   ` [dpdk-dev] [PATCH v1 2/4] net/virtio: add vectorized packed ring Rx NEON path Joyce Kong
2021-01-05 14:16     ` Maxime Coquelin
2021-01-05 14:27       ` Maxime Coquelin
2021-01-07 10:39         ` Maxime Coquelin [this message]
2021-01-08  7:29           ` Joyce Kong
2021-01-08 17:02     ` Ferruh Yigit
2021-01-08 22:26       ` Honnappa Nagarahalli
2021-01-11 13:05         ` Aaron Conole
2021-01-11 10:45       ` Maxime Coquelin
2021-01-11 13:04       ` Aaron Conole
2020-11-17 10:06   ` [dpdk-dev] [PATCH v1 3/4] net/virtio: add vectorized packed ring Tx " Joyce Kong
2021-01-05 14:33     ` Maxime Coquelin
2020-11-17 10:06   ` [dpdk-dev] [PATCH v1 4/4] net/virtio: add election for packed vector " Joyce Kong
2021-01-05 14:42     ` Maxime Coquelin
2021-01-08  9:11   ` [dpdk-dev] [PATCH v1 0/4] Vectorize packed ring RX/TX path with NEON Maxime Coquelin

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