From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 59E89C4167D for ; Wed, 8 Nov 2023 17:16:26 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 989B32A8F9 for ; Wed, 8 Nov 2023 17:16:25 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 6D110986CAA for ; Wed, 8 Nov 2023 17:16:25 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id 5236B986CA7; Wed, 8 Nov 2023 17:16:25 +0000 (UTC) Mailing-List: contact virtio-comment-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk 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 4255E986CA8 for ; Wed, 8 Nov 2023 17:16:25 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 01dG7nC2OIO3lPKe2PbbjQ-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699463781; x=1700068581; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=FMPJYG9eORGfIUyThIV6RXmczovN+LFJfLZubUvgX6U=; b=ubq5ScrBBqhPt9bxTkqShUs6fhNWtpEvgA+KWM/tHi+nynuIO3jxHIF8zCilnRGdxu rvjnHHyhMe9X/TE6L8DClmefmaLVTjKTxPv501dmyzdrk0KyfU/vZFmICvPkUPaa+p06 mSa/66L5B14uDn7oRIRW/nVKMbG4VhGHHLoM8/l6+XNegBYIpGzpSMoaQw38o4nHBX+h AFK5sULlo4o1H998ByNz6PkAZt6Hgqq299k5WblhpKXInxBBLr7v/tTtnhjAK4N3EriH OuDn+3/9uBOAa1FzHfPbnd48sum4A/kut6zUB7rkkbZ2xDJ9XmSFTmEkv4pZZT/DTOjb xcZw== X-Gm-Message-State: AOJu0Yx55FVNx3de5NPFWKYbVXk8ZPuMulXFG69GrAT0NZO+U0xQY+qa Fnsv14SpsPvbbbzv0zTMauI27a7rtgHhSh2Hdbl8nE9WYj8jEAdZwSyXcBR3g3XUlaUj7zWY2z2 MM770PG6yI4ylfKz5OJr3TKAxrNDiQoCk8Q== X-Received: by 2002:a05:651c:1986:b0:2c5:1674:8d79 with SMTP id bx6-20020a05651c198600b002c516748d79mr2933725ljb.21.1699463781265; Wed, 08 Nov 2023 09:16:21 -0800 (PST) X-Google-Smtp-Source: AGHT+IGBgCyayAx+tVFwwaNIknFCx1M3xZv2JUF65k6TQKFJjebOgH44mcjY4CuX7JnTo3Ek2rK68g== X-Received: by 2002:a05:651c:1986:b0:2c5:1674:8d79 with SMTP id bx6-20020a05651c198600b002c516748d79mr2933698ljb.21.1699463780813; Wed, 08 Nov 2023 09:16:20 -0800 (PST) Date: Wed, 8 Nov 2023 12:16:14 -0500 From: "Michael S. Tsirkin" To: Parav Pandit Cc: Jason Wang , "virtio-comment@lists.oasis-open.org" , "cohuck@redhat.com" , "sburla@marvell.com" , Shahaf Shuler , Maor Gottlieb , Yishai Hadas , "lingshan.zhu@intel.com" Message-ID: <20231108120828-mutt-send-email-mst@kernel.org> References: <20231107015412-mutt-send-email-mst@kernel.org> <20231108025854-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [virtio-comment] Re: [PATCH v3 6/8] admin: Add theory of operation for write recording commands On Wed, Nov 08, 2023 at 09:00:00AM +0000, Parav Pandit wrote: > > From: Michael S. Tsirkin > > Sent: Wednesday, November 8, 2023 1:47 PM > > > Only for TX, and I'm pretty sure they had the foresight to test RX not just TX but > > let's confirm. Parav did you test both directions? > Rx is the main part to test for the dirty page tracking. > Tx only is around ring updates, so not very interesting test. > > When page tracking is started, there is impact on Rx as natural throttle by slowing down rx packet rate. Wait a sec sounds kind of like what we see with SVQ as well? > And devices have implementation choice to covering the spectrum on amount of drop rate. What does this mean practically? > And has implementations evolve, it will improve as well. Maybe, or maybe not. > PRI for sure is out of question. Most workload won't use it at all given other limitations of virtio on PCI front and existing PRI behaviors. Out of curiousity what do you refer to? > There is also a test with platform IOMMU dirty page tracking done as well but it is very early stage to comment in this forum. Interesting. That's a very important test I'd say - if platform based dirty page tracking is just as good we can avoid adding it to virtio. And I'm rather confused at this point - I was under the impression you already have a prototype which shows negligeable performance impact with on device tracking. -- 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/