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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?N/sMedg17XLb5fEwFbeJRVFghGD9YwHBIIEAujRjxICu4CdNg8xCXUdli+rZ?= =?us-ascii?Q?BcPHOC5Dyxkru7YcPHF1/Uapnru9bFEwXThJCMyS4fhjsxAY3+7WVfbJLadR?= =?us-ascii?Q?uerW2RDTgCadL46jFMFG1Rr+orIR6fmePmPOT6Iqc2wZtNx88qAS9gNTg3S9?= =?us-ascii?Q?hoxHmMSTsQdzR5l5Zok2iBIlojAGD6qQlJ2A7AjRh//0z59Oo2kQXk2AmSyr?= =?us-ascii?Q?Tig1RwinS5Qy3uIPZOis3RgXwbbxHynp0Y0BK+xJ90YQB/Aw1R7UjT30xe15?= =?us-ascii?Q?g/E72kNNwWOo1HrF+5Ed50LcXiQVSl4lSskP0LRBpOoGtJJe2fn7Xmh1MnI0?= =?us-ascii?Q?hAJ2VQiPcUZ8Mser+TgIhNiOXF6bt6s59Am8GMaqiuDxKtZQw2le/BmfVjpM?= =?us-ascii?Q?zQb2KUd6vzdYvSbPI/9mE+NqhyPXwpoEdTkDMS4SFTeLSgSVsv2tWB/TaFh7?= =?us-ascii?Q?dMIbr2lar/mi0qyt4etTOxvQr9+6WvReqFHoRNngGQdvL/k1E3403pzixNfE?= =?us-ascii?Q?ZtsDdCXsjn+jZGD8tEquaLFiCE2eNC2Q2l1UZ/uKcGX8Oi7kFhDkXaj42aXE?= =?us-ascii?Q?FrmcWfLlnMjwl7HsU5yD7O17Kdn8j0fBnL9Ja7mvF71JO5JWcB9v8GgKFQq6?= =?us-ascii?Q?sn0TUT8O7GEVpeYAlZ/j7vVcZ2ViPOab0tLDnAvKIAT9Ul9+cSfIf/OMQEDk?= =?us-ascii?Q?5vVUYGCO7Gh0jgg2bakL+kj1ZmXbUKsKy5GIxsl6rODBgKnSCJh2+oLiAP4q?= =?us-ascii?Q?x8p+gp/Si0sooBw1RYLu4nvYMcDk1oDXRFKDxupKiMc6QjkFRGWOJMvTGU1r?= =?us-ascii?Q?O5SaKmSB7oIfi8TShrHu1H62F3Ym8vbEytFv+xr2YdlCxN3FJ64hH22HJPfm?= =?us-ascii?Q?3TQAAooFIFfu95hUMuGGj6/ISpxJRNSJRnbMrNF6UWQOQ8yRhzQ+9Cd73sXQ?= =?us-ascii?Q?a4Png8FxCcbE7WSZ5B+tE9Vjg+HgIZ2aRs+FsmoQsfolOXvb9KXEFrFVtPDd?= =?us-ascii?Q?cOFrdkpHopMElqfDx1ZUFHgRCF2w62ht4xH6XpQ0MYovixWMMstT3g0CWAZV?= =?us-ascii?Q?6STV5/2pNk3ifBT6VRQJyiuiAhqcKFCEIw+vMCzdj4P5V/cRjdhqR0x6kkzy?= =?us-ascii?Q?aakUJOhUjY6vvf/VffOnhsoWkQjoSxCYfWWjXjfkDGNSJ/arlpJGmtk3aZuL?= =?us-ascii?Q?eNHLbjit/ikVJ/yonpIeM8Kam4gqrDMsX0/7oocb9X648jmlpwK1ksyZf0Hs?= =?us-ascii?Q?BFRdKOwaW5ZQMeEQmlHd30Wre+7TOGmS4SqkJ3HGE3731+THJ1NUdNanERhG?= =?us-ascii?Q?hF3jh7KFLHWS5fhs2Zi+kSHXPJwhqfJ/de/VFWzB4Y8f9/j/ttEPg3zG0aKr?= =?us-ascii?Q?wmzYkzjEA0loZsUBiY9fHzg6ZXiXB0gNDhDvUnrZTacXT9YBH2qOmVXEyAOT?= =?us-ascii?Q?iBHy26BgVHHzGDIVQ2bIbbejLnC/TeQtikFQ3DXaC6evU3j/lPeltk42RyVJ?= =?us-ascii?Q?qiCxI9GlS7Ive0Tt0qUGOpjKiO99rp11RScqvidNE+iBb44geANT22PJ5ybd?= =?us-ascii?Q?yEMwxXwmSuSTaTF+oP5rCX/H6P+H6P/GoO85KMdl6BmqDxgA9QKMNGD7gDaY?= =?us-ascii?Q?TA=3D=3D?= X-OriginatorOrg: memverge.com X-MS-Exchange-CrossTenant-Network-Message-Id: 95a65911-6084-4f78-da6e-08dbe5297d35 X-MS-Exchange-CrossTenant-AuthSource: SJ0PR17MB5512.namprd17.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Nov 2023 15:50:56.2024 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 5c90cb59-37e7-4c81-9c07-00473d5fb682 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: ygdfaZKyuKRN0kmHIX6KO4u20g8QAoo0d8eWYpPFsq+w0Cnrfgfp+O4FpONt/YcprPCRisf6jHfwzSLHiy3BU7Q7XAj3v/1mSkl1F9qVQRs= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR17MB3966 On Tue, Nov 14, 2023 at 10:43:13AM +0100, Michal Hocko wrote: > On Fri 10-11-23 22:42:39, Gregory Price wrote: > [...] > > If I can ask, do you think it would be out of line to propose a major > > refactor to mempolicy to enable external task's the ability to change a > > running task's mempolicy *as well as* a cgroup-wide mempolicy component? > > No, I actually think this is a reasonable idea. pidfd_setmempolicy is a > generally useful extension. The mempolicy code is heavily current task > based and there might be some challenges but I believe this will a) > improve the code base and b) allow more usecases. Just read up on the pidfd_set_mempolicy lore, and yes I'm seeing all the same problems (I know there was discussion of vma policies, but i think that can be a topic for later). Have some thoughts on this, but will take some time to work through a few refactoring tickets first. > > That being said, I still believe that a cgroup based interface is a much > better choice over a global one. Cpusets seem to be a good fit as the > controller does control memory placement wrt NUMA interfaces. I think cpusets is a non-starter due to the global spinlock required when reading informaiton from it: https://elixir.bootlin.com/linux/latest/source/kernel/cgroup/cpuset.c#L391 Unless the proposal is to place the weights as a global cgroups value, in which case I think it would be better placed in default_mempolicy :]