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X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Oct 2024 11:59:42.0544 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 4b78d74b-9c9b-46a9-9e46-08dcf8112c48 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CO1PEPF000066EA.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR12MB7150 On 28/10/2024 18:23, Jason Gunthorpe wrote: > On Mon, Oct 28, 2024 at 10:13:48AM -0600, Alex Williamson wrote: >> On Sun, 27 Oct 2024 12:07:44 +0200 >> Yishai Hadas wrote: >> If the virtio spec doesn't support partial contexts, what makes it >> beneficial here? > > It stil lets the receiver 'warm up', like allocating memory and > approximately sizing things. > >> If it is beneficial, why is it beneficial to send initial data more than >> once? > > I guess because it is allowed to change and the benefit is highest > when the pre copy data closely matches the final data.. > > Rate limiting does seem better to me > > Jason Right, given that the device state is likely to remain mostly unchanged over a certain period, using a rate limiter could be a sensible approach. So, in V1, I plan to replace the hard-coded limit value of 128 with a rate limiter by reporting no data available for some time interval after the previous call. I would start with a one second interval, which seems to be reasonable for that kind of device. Yishai