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 5B33CA0C43; Tue, 14 Sep 2021 09:33:43 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id D88534068F; Tue, 14 Sep 2021 09:33:42 +0200 (CEST) Received: from shelob.oktetlabs.ru (shelob.oktetlabs.ru [91.220.146.113]) by mails.dpdk.org (Postfix) with ESMTP id 770F54003C; Tue, 14 Sep 2021 09:33:41 +0200 (CEST) Received: from [192.168.38.17] (aros.oktetlabs.ru [192.168.38.17]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by shelob.oktetlabs.ru (Postfix) with ESMTPSA id 6349D7F50A; Tue, 14 Sep 2021 10:33:40 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 shelob.oktetlabs.ru 6349D7F50A DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=oktetlabs.ru; s=default; t=1631604820; bh=ZLKwnoh0/DdKT3oyVE45ApDGcUiodstEWBjFM2d/Z8w=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=mnsBL2kNbG82DSFCoeHXjgUWdyZeUM3hPGXUf6u+FBHmkJilYA9lJG+olph+wt9Vv ZY0MlC8QHHZ/W4fcU9YMB3ibtb2EEtTV12RV6A7xAoVmQkoh29nEx/r5Liv/bShPyt uxg184lD+F/wkLBWBMa0nFQ08Wpc2GKN6IGucLVU= To: Maxime Coquelin , 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> <17b58919-03a7-db3b-0c2d-612b3f365768@redhat.com> From: Andrew Rybchenko Organization: OKTET Labs Message-ID: Date: Tue, 14 Sep 2021 10:33:40 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <17b58919-03a7-db3b-0c2d-612b3f365768@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 10:26 AM, Maxime Coquelin wrote: > > > 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. Thanks, Andrew. > Maxime >> >>> Other than that: >>> Reviewed-by: Maxime Coquelin >> >> Thanks, >> Andrew. >>