From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 0C960986534 for ; Wed, 8 Feb 2023 22:57:28 +0000 (UTC) Date: Wed, 8 Feb 2023 17:57:14 -0500 From: "Michael S. Tsirkin" Message-ID: <20230208175438-mutt-send-email-mst@kernel.org> References: <20230208094015-mutt-send-email-mst@kernel.org> <20230208094504-mutt-send-email-mst@kernel.org> <20230208154819-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Subject: Re: [virtio-comment] [PATCH] virtio-net: support per-queue coalescing moderation Content-Type: text/plain; charset=us-ascii Content-Disposition: inline To: Alvaro Karsz Cc: Parav Pandit , Heng Qi , Xuan Zhuo , "virtio-comment @ lists . oasis-open . org" , "virtio-dev @ lists . oasis-open . org" , Jason Wang List-ID: On Thu, Feb 09, 2023 at 12:35:42AM +0200, Alvaro Karsz wrote: > > > From: Alvaro Karsz > > > Sent: Wednesday, February 8, 2023 4:56 PM > > > > > > Alvaro, > > > > Do you know if any software used it? Can you get some real data? > > > > > > I implemented this feature in our DPU, so at least 1 vendor is using this feature > > > > But which software (virtio net driver) in which OS is using this? > > Sorry, I'm not sure I understand your question. > > The feature is implemented in the linux kernel > https://github.com/torvalds/linux/commit/699b045a8e43bd1063db4795be685bfd659649dc > So we'll always have kernel versions accepting this feature, if offered. > > > > (I will add support for the per vq command of course). > > > I really don't know about other vendors.. > > > > > > You are suggesting to reserve the command and feature bit for safety, so, if we > > > reserve them, why not just use them? What do we lose here? > > > > > If it is used by some unknown software, only that sw breaks by using non release spec. > > If we use it by changing the definition, it may break that unknown sw. > > If we know there is no known sw, we are better of with redefinition (by adding vqn, and by removing tx,rx from it). > > > > > Not having this feature/command even complicates things now that we are > > > talking about removing the RX and TX from the per vq command, how do you > > > change parameters to all TX queues? to all RX queues? we'll need 2 special > > > indexes, so we now need le32 to hold the queue index. > > No need for special index. > > How does a driver disable all queues or reset all queues? -> One by one. > > So if user want to change for all TXQ, sw can do it one by one by iterating TXQ vqns. > > Yes, but resetting the queues doesn't require a control command. > If a server has 64K queues, and a user wants to set all coalescing > parameters to X (maybe with ethtool), it will generate 64K control > commands.. Amount of time spent on bike-shedding here is mind-boggling. Pls just send a new version and we'll go from there. In the end it's a majority we don't have to have consensus if we can't get it. -- MST This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/