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 19BCAA0C47; Tue, 14 Sep 2021 08:40:12 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 9497A4068F; Tue, 14 Sep 2021 08:40:11 +0200 (CEST) Received: from shelob.oktetlabs.ru (shelob.oktetlabs.ru [91.220.146.113]) by mails.dpdk.org (Postfix) with ESMTP id 656204003C; Tue, 14 Sep 2021 08:40:10 +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 BFF337F514; Tue, 14 Sep 2021 09:40:09 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 shelob.oktetlabs.ru BFF337F514 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=oktetlabs.ru; s=default; t=1631601609; bh=3FyAYbF+q3uAcndwlYrcgAcS+zA2TRTuoyrZx4t5fiQ=; h=Subject:To:Cc:References:From:Date:In-Reply-To; b=eJEoPMk5tE2UV6FA6lAnERUMda2s97VGVMmG9HwdETYjn48f7nSk5kFaAEhkpigic nmgoEq7yOehLkDr9Q/jZaUnOZ1ec0cE9v6AIAVjvuL1DUR4dNJDwWzhy7263M4s149 5mEDJIfXk8Buin0j/3qgYr+4PppTmIfBxbfMo78M= 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> From: Andrew Rybchenko Organization: OKTET Labs Message-ID: <997133b4-176e-44f2-1340-b66a3a72e182@oktetlabs.ru> Date: Tue, 14 Sep 2021 09:40:09 +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: <47446316-5d49-9bf7-1d6c-3a422e045e11@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 9/13/21 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. > Other than that: > Reviewed-by: Maxime Coquelin Thanks, Andrew.