From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124])
by inbox.dpdk.org (Postfix) with ESMTP id 6C503A054F;
Mon, 15 Mar 2021 14:46:33 +0100 (CET)
Received: from [217.70.189.124] (localhost [127.0.0.1])
by mails.dpdk.org (Postfix) with ESMTP id 579E1242666;
Mon, 15 Mar 2021 14:46:33 +0100 (CET)
Received: from us-smtp-delivery-124.mimecast.com
(us-smtp-delivery-124.mimecast.com [216.205.24.124])
by mails.dpdk.org (Postfix) with ESMTP id 6C4284003C
for <dev@dpdk.org>; Mon, 15 Mar 2021 14:46:32 +0100 (CET)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;
s=mimecast20190719; t=1615815991;
h=from:from:reply-to:subject:subject:date:date:message-id:message-id:
to:to:cc:mime-version:mime-version:content-type:content-type:
content-transfer-encoding:content-transfer-encoding:
in-reply-to:in-reply-to:references:references;
bh=4rjO4SNsZJQ1pu2WhBZw9DCKUlQOc827rTIWvx6Btgg=;
b=D4pFpfskRHJ+gCUmTzQVEFoKpbpalIDQeTaII0qxY9qPoUMtTBg4JxGqND21/mMZfycUO/
qaHsphez2TuGVPcN58Uub1VFSPaCAa8OXF1Ao1dj4WhFissH+H5FZgXwkQsH/gl78ZopXG
rXn6L5CPT+tC3UZdB+1XKrhlhZ3r3A8=
Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com
[209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id
us-mta-215-KdVIaeZuPy6aBKesweFh3Q-1; Mon, 15 Mar 2021 09:46:28 -0400
X-MC-Unique: KdVIaeZuPy6aBKesweFh3Q-1
Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com
[10.5.11.13])
(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
(No client certificate requested)
by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 758D9760C5;
Mon, 15 Mar 2021 13:46:27 +0000 (UTC)
Received: from [10.36.110.10] (unknown [10.36.110.10])
by smtp.corp.redhat.com (Postfix) with ESMTPS id B1AA96060F;
Mon, 15 Mar 2021 13:46:22 +0000 (UTC)
To: "Xia, Chenbo" <chenbo.xia@intel.com>, "dev@dpdk.org" <dev@dpdk.org>,
"amorenoz@redhat.com" <amorenoz@redhat.com>,
"david.marchand@redhat.com" <david.marchand@redhat.com>,
"olivier.matz@6wind.com" <olivier.matz@6wind.com>
References: <20201221161456.31696-1-maxime.coquelin@redhat.com>
<20201221161456.31696-3-maxime.coquelin@redhat.com>
<MN2PR11MB40632092D9DCC5451FBF9E459CAB0@MN2PR11MB4063.namprd11.prod.outlook.com>
From: Maxime Coquelin <maxime.coquelin@redhat.com>
Message-ID: <fc9d8078-991a-c2e8-a8d9-6a80c86b0b50@redhat.com>
Date: Mon, 15 Mar 2021 14:46:21 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
Thunderbird/78.8.0
MIME-Version: 1.0
In-Reply-To: <MN2PR11MB40632092D9DCC5451FBF9E459CAB0@MN2PR11MB4063.namprd11.prod.outlook.com>
X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13
Authentication-Results: relay.mimecast.com;
auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=maxime.coquelin@redhat.com
X-Mimecast-Spam-Score: 0
X-Mimecast-Originator: redhat.com
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Subject: Re: [dpdk-dev] [PATCH 2/3] net/virtio: allocate fake mbuf in Rx
queue
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
<mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>
On 1/11/21 6:39 AM, Xia, Chenbo wrote:
> Hi Maxime,
>
>> -----Original Message-----
>> From: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Sent: Tuesday, December 22, 2020 12:15 AM
>> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; amorenoz@redhat.com;
>> david.marchand@redhat.com; olivier.matz@6wind.com
>> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Subject: [PATCH 2/3] net/virtio: allocate fake mbuf in Rx queue
>>
>> While it is worth clarifying whether the fake mbuf
>> in virtnet_rx struct is really necessary, it is sure
>> that it heavily impacts cache usage by being part of
>> the struct. Indeed, it takes uses cachelines, and
>> requires alignement on a cacheline.
>>
>> Before this series, it means it took 120 bytes in
>> virtnet_rx struct:
>>
>> struct virtnet_rx {
>> struct virtqueue * vq; /* 0 8 */
>>
>> /* XXX 56 bytes hole, try to pack */
>>
>> /* --- cacheline 1 boundary (64 bytes) --- */
>> struct rte_mbuf fake_mbuf __attribute__((__aligned__(64)));
>> /* 64 128 */
>> /* --- cacheline 3 boundary (192 bytes) --- */
>>
>> This patch allocates it using malloc in order to optimize
>> virtnet_rx cache usage and so virtqueue cache usage.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>> drivers/net/virtio/virtio_ethdev.c | 10 ++++++++++
>> drivers/net/virtio/virtio_rxtx.c | 8 +++-----
>> drivers/net/virtio/virtio_rxtx.h | 2 +-
>> 3 files changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/net/virtio/virtio_ethdev.c
>> b/drivers/net/virtio/virtio_ethdev.c
>> index 297c01a70d..a1351b36ca 100644
>> --- a/drivers/net/virtio/virtio_ethdev.c
>> +++ b/drivers/net/virtio/virtio_ethdev.c
>> @@ -539,6 +539,7 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t
>> queue_idx)
>> }
>>
>> if (queue_type == VTNET_RQ) {
>> + struct rte_mbuf *fake_mbuf;
>> size_t sz_sw = (RTE_PMD_VIRTIO_RX_MAX_BURST + vq_size) *
>> sizeof(vq->sw_ring[0]);
>>
>> @@ -550,10 +551,18 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t
>> queue_idx)
>> goto fail_q_alloc;
>> }
>>
>> + fake_mbuf = malloc(sizeof(*fake_mbuf));
>> + if (!fake_mbuf) {
>> + PMD_INIT_LOG(ERR, "can not allocate fake mbuf");
>> + ret = -ENOMEM;
>> + goto fail_q_alloc;
>> + }
>> +
>> vq->sw_ring = sw_ring;
>> rxvq = &vq->rxq;
>> rxvq->port_id = dev->data->port_id;
>> rxvq->mz = mz;
>> + rxvq->fake_mbuf = fake_mbuf;
>> } else if (queue_type == VTNET_TQ) {
>> txvq = &vq->txq;
>> txvq->port_id = dev->data->port_id;
>> @@ -636,6 +645,7 @@ virtio_free_queues(struct virtio_hw *hw)
>>
>> queue_type = virtio_get_queue_type(hw, i);
>> if (queue_type == VTNET_RQ) {
>> + free(vq->rxq.fake_mbuf);
>
> After thinking about this again, although you add the free of fake mbuf
> here, it's better to add free in virtio_init_queue too after fail_q_alloc.
> And when setup_queue(hw, vq) fails, it's better to goto fail_q_alloc to
> free fake mbuf. Now it will not memory leak as we use virtio_free_queues when
> virtio_alloc_queues fails. But inside virtio_init_queue, it's better to
> handle the errors well.. If you agree with above, it may also be good to
> change the name 'fail_q_alloc' since now it may also fail when setting up
> queues.
The error path indeed needs some rework.
I will add a preliminary patch to rework it before this patch is
applied.
> Sorry for an extra email about this...
No worries, that's much appreciated!
Thanks,
Maxime
> Thanks,
> Chenbo
>
>> rte_free(vq->sw_ring);
>> rte_memzone_free(vq->rxq.mz);
>> } else if (queue_type == VTNET_TQ) {
>> diff --git a/drivers/net/virtio/virtio_rxtx.c
>> b/drivers/net/virtio/virtio_rxtx.c
>> index 1fcce36cbd..d147d7300a 100644
>> --- a/drivers/net/virtio/virtio_rxtx.c
>> +++ b/drivers/net/virtio/virtio_rxtx.c
>> @@ -703,11 +703,9 @@ virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev,
>> uint16_t queue_idx)
>> virtio_rxq_vec_setup(rxvq);
>> }
>>
>> - memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf));
>> - for (desc_idx = 0; desc_idx < RTE_PMD_VIRTIO_RX_MAX_BURST;
>> - desc_idx++) {
>> - vq->sw_ring[vq->vq_nentries + desc_idx] =
>> - &rxvq->fake_mbuf;
>> + memset(rxvq->fake_mbuf, 0, sizeof(*rxvq->fake_mbuf));
>> + for (desc_idx = 0; desc_idx < RTE_PMD_VIRTIO_RX_MAX_BURST; desc_idx++) {
>> + vq->sw_ring[vq->vq_nentries + desc_idx] = rxvq->fake_mbuf;
>> }
>>
>> if (hw->use_vec_rx && !virtio_with_packed_queue(hw)) {
>> diff --git a/drivers/net/virtio/virtio_rxtx.h
>> b/drivers/net/virtio/virtio_rxtx.h
>> index 7f1036be6f..6ce5d67d15 100644
>> --- a/drivers/net/virtio/virtio_rxtx.h
>> +++ b/drivers/net/virtio/virtio_rxtx.h
>> @@ -19,7 +19,7 @@ struct virtnet_stats {
>>
>> struct virtnet_rx {
>> /* dummy mbuf, for wraparound when processing RX ring. */
>> - struct rte_mbuf fake_mbuf;
>> + struct rte_mbuf *fake_mbuf;
>> uint64_t mbuf_initializer; /**< value to init mbufs. */
>> struct rte_mempool *mpool; /**< mempool for mbuf allocation */
>>
>> --
>> 2.29.2
>