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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Y5aYtQNR25+algwOZDneW0kScR0/grlP0bNHyJGC4J2M4Yy6vwFAkdCK7OYT?= =?us-ascii?Q?iqA8P/qY+Fn/YdRU8TTvuSBhtHP4UQPrY8c+SqypSjbi50XQnMvXDMII9eSE?= =?us-ascii?Q?H9DWiRloIfKpTQpO6QgjefZwc86F82j9LhHDeIjoAemQ4vuOvVc2bIUHQqfW?= =?us-ascii?Q?HLb5bpVKkLAE2kPvRPQx2Wj0c6pVQkDDD1rdk+DEO++oDrl4TBz+03WKY3qO?= =?us-ascii?Q?SS73XkKm149dYyDV2VU7Qzyh0F8NH7acwhNew03JN+6oGHTCJ5PwIVo5Ok+/?= =?us-ascii?Q?8g8BEyY6hz7WPWZ7MJn5qulSLIl+JhDwR7hWv2hDXmk4cn8uZle9XDkvWh6X?= =?us-ascii?Q?tp7XzQA0Jy+qKmFN+kr/sSV4g3A3PEsuGortaHbue/GYdf+ZOiyqCnyD6ExZ?= =?us-ascii?Q?35UgFa5AyjEPWzQuABNZBHw3O0trA4ZbHWq/VFUIRdpSV29WOwf2gclnSQfr?= =?us-ascii?Q?A9yqICaQpxqQXx1cseFK7W4dIUqkKmtKCTdIFVvdpgDFj/hGRbVCxvJXAHaJ?= =?us-ascii?Q?goZm+d8LlvknFKC56rA1FrkuAVxVc4VkUY6yqgY3CT2sLiUDzrDUatb/QVVe?= =?us-ascii?Q?iWdFGHuoKK6Wx/X+ExA2+5Y4dATuEStK7xz2dsR9ydaJ/vpPWGYazoMFrDcB?= =?us-ascii?Q?BN/g00hQdiss4HFB7lJzpvrBBd0b1lCegEK63KXiMh8gRR96Ev/MF98HmaLE?= =?us-ascii?Q?wFPj16gaffMYOgjMfKxtXO8wdt9ZYDAXNftogN3ecXOG8he58YjYNDGspT9E?= =?us-ascii?Q?BVaYcGHE+rGf4Bbc734JU+aBmzmfQc0MBtUFYcSZViVO1nmrE4xWq1PD68x8?= =?us-ascii?Q?+RfymkrGoo2k3vocNjq6Re5FmGKhKXH/1YT8/Ymt0xJ6VI9Fn4366/rgSY8S?= =?us-ascii?Q?ZQgVP9K0YiA0gguyeg9xjGkkIqPPuKs5Ll7T9cKLvqv8gmBQzepDOKgbiHg6?= =?us-ascii?Q?+hgDNE9yQyQeQcs3O1MF+Em1Lgdr7UjdxHaqBms1dtfEVOMH805ryEBtYuFp?= =?us-ascii?Q?Bi9dTqaqgsI6K8aIWoPGqi/TNGva+dppBtY0PoqQk1x6gOxGpv3OHms5uIr2?= =?us-ascii?Q?zy277c4UzzVpF8IjRV6FELbaA5XlQWX47elojgUuD8Fzbksb422lGpFT4dgy?= =?us-ascii?Q?OHgHMlvPPikTbmYEzlO2GFD0d8s5LWIntNQKpbtWFzIR8bqwFM29G8FYw8kt?= =?us-ascii?Q?4u4bhgmJInd2jruP+lWcuO0JdQcqJq+rlSux2pv2RneBbFcDX2loj1kUY4rq?= =?us-ascii?Q?aY97jTcEhC9cQ8zzXaRTIIJEJDfPA+kYgZG463SWkS+iyQBaMkelubxnHs//?= =?us-ascii?Q?eBnurNQRogTOoFgwMhon/DU0XYyuxetXdV1PfRjt2RXCD8MkmcAGy6kmrL3+?= =?us-ascii?Q?ZiiN7sUe1q35u/eeN1eXOLbhuvhHMhNGI70gR23fF196e/q/iJmtC5Qrx3g0?= =?us-ascii?Q?sSESIJF4GcHohSIC+hsyEugCdLf3Pqa82l6XYTlUS+145KX9USJUiQF9/nc/?= =?us-ascii?Q?YasQqKVnuCzeeOp14nW5E4VkyYTuRJXm3rEq9+7yuFMPmaXHDXZJ7sTrTXQN?= =?us-ascii?Q?pqw2k8/BR78mLmAsyaZGse59IQkXr+JQEeDT5igD?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2211a832-49a5-4542-84e9-08dd75dfc2c7 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Apr 2025 14:23:26.4596 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Bk6hQfpUpya+DMbNcKh1mHZbOj5KBBQCVz/bz9lrlRlZMHfLSXQrvZJf0D9z+Bpv X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB7167 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250407_072331_407988_2BD295B8 X-CRM114-Status: GOOD ( 10.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun, Apr 06, 2025 at 07:34:30PM +0300, Mike Rapoport wrote: > It's more than 200 line longer than maple tree if we count the lines. > My point is both table and xarrays are trying to optimize for an unknown > goal. Not unknown, the point of the bitmap scheme is to be memory deterministic. You can measure your workload and you can say I need XX MB of memory to succeed a KHO using bitmaps. With maple tree you need to both measure your work load, compute a worst case fragmentation, then say you need YY MB of memory to succeed the KHO. Since we are looking only at worst case YY > XX These are engineered systems, there is limited memory available to the hypervisor, and every MB is basically accounted for to minimize the memory requirement. So every action needs to be worst cased and accounted for in the hypervisor memory budget. > As I said, this means an alternative implementation of the memory map and > free lists, which has been and remains quite fragile. > So we'd better start with something that does not require that in the > roadmap. I think the obvious next step is to use the bitmaps to generate contiguous ranges to pass into memblock reserve. That will get you performance equivilent to mapletree and deterministic memory usage. Jason