From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 7522EA0C47; Tue, 14 Sep 2021 09:26:36 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 56E914069C; Tue, 14 Sep 2021 09:26:36 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id 201724069C for ; Tue, 14 Sep 2021 09:26:35 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631604394; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tRnQ7AwgWhPdnAclooV/mjQ/A133NZg12qZr+WjfpkI=; b=bfR58JmBrDAiZi+vutM6zZ5j884Egy1bYAazV5gFT1wrw6Nmv9B8oKnhp7yMhX5v9OpMYv tjxwyu6fRHttkVobf7IpNY+IV292IynXcNblRPr92aOmB4tM3IUmC91xUlgZt965DHd1jM lpx2HV36IvgZi7a6Q1HKCYoKfDojoEY= 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-468-xGdaLua5Pmad2DkyJQu2Sw-1; Tue, 14 Sep 2021 03:26:31 -0400 X-MC-Unique: xGdaLua5Pmad2DkyJQu2Sw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CC0531006AA3; Tue, 14 Sep 2021 07:26:29 +0000 (UTC) Received: from [10.39.208.12] (unknown [10.39.208.12]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C4C286B54B; Tue, 14 Sep 2021 07:26:27 +0000 (UTC) To: Andrew Rybchenko , Chenbo Xia , Shreyansh Jain , Remy Horton , Ferruh Yigit , Thomas Monjalon Cc: dev@dpdk.org, Ivan Ilchenko , stable@dpdk.org References: <20210820124741.3522576-1-andrew.rybchenko@oktetlabs.ru> <47446316-5d49-9bf7-1d6c-3a422e045e11@redhat.com> <997133b4-176e-44f2-1340-b66a3a72e182@oktetlabs.ru> From: Maxime Coquelin Message-ID: <17b58919-03a7-db3b-0c2d-612b3f365768@redhat.com> Date: Tue, 14 Sep 2021 09:26:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <997133b4-176e-44f2-1340-b66a3a72e182@oktetlabs.ru> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 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: 7bit Subject: Re: [dpdk-dev] [PATCH] net/virtio: remove handling of zero desc number on RxQ setup X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 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" On 9/14/21 8:40 AM, Andrew Rybchenko wrote: > On 9/13/21 10:25 PM, Maxime Coquelin wrote: >> >> >> On 8/20/21 2:47 PM, Andrew Rybchenko wrote: >>> From: Ivan Ilchenko >>> >>> Rx queue setup callback allows to use the whole ring when >>> descriptor number argument equals zero. There's no point to >>> handle zero in any way since RTE Rx queue setup function >>> rte_eth_rx_queue_setup() doesn't pass zero using fallback >>> values. >>> >>> Fixes: 3be82f5cc5e3 ("ethdev: support PMD-tuned Tx/Rx parameters") >>> Cc: stable@dpdk.org >>> >>> Signed-off-by: Ivan Ilchenko >>> Signed-off-by: Andrew Rybchenko >>> --- >>> drivers/net/virtio/virtio_rxtx.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c >>> index 8a48fba5cc..18f03c9fc9 100644 >>> --- a/drivers/net/virtio/virtio_rxtx.c >>> +++ b/drivers/net/virtio/virtio_rxtx.c >>> @@ -706,7 +706,7 @@ virtio_dev_rx_queue_setup(struct rte_eth_dev *dev, >>> } >>> vq->vq_free_thresh = rx_free_thresh; >>> >>> - if (nb_desc == 0 || nb_desc > vq->vq_nentries) >>> + if (nb_desc > vq->vq_nentries) >>> nb_desc = vq->vq_nentries; >>> vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc); >>> >>> >> >> Is that really a fix? >> I see it more like an optimization in a cold path, so maybe it is not >> worth backporting? > > The main idea is not an optimization, but simplification of > the code to make it easier to understand. Less special > cases is better. > > I agree that it does not make sense to backport it. Ok, thanks. I'll will remove the Fixes tag while applying, no need to resubmit. Maxime > >> Other than that: >> Reviewed-by: Maxime Coquelin > > Thanks, > Andrew. >