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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?rbPk80CbsS4ovs3FoDhlD+TZfoeT5k5zVBbkr5w/8fP8yT+UBSgZjVJkrDRx?= =?us-ascii?Q?vdSSBDFNUhj5XywfffZGoKjUVuwwGzP6UojP5B6B+jVli1XjCWQ0uHCBPWPS?= =?us-ascii?Q?MllDIkkSTxtwQmjXHNRCKRLqnq5+CCBqqt0S1iYV2xCc/fHagOR3cL6tYfPu?= =?us-ascii?Q?eB2qxrj/jLOIaPf9eitr9Nwr+ECyoAsr/di41GJTTA1H93DfGtAr4xgxYr1v?= =?us-ascii?Q?4vAKETL0Yl+yks+xCQkZlrJvI8oKvB6Y4G8SYi1P0eAeRPqRTlYzYPEjifLo?= =?us-ascii?Q?kgnQc0tnNCLNr7Ua09KXihiIfvyPoICUF/X48mKi2CyGNkBYxg8e1mA3osvf?= =?us-ascii?Q?khKs5aq2CgstLubhUxnVbesYcmbbBlJ1evtoJRCbD3dpT0GgsdqZq93iWYnV?= =?us-ascii?Q?aiFj/unFNv+uwyK5BoHQfKefUJZn4aprvukSFZdmz0Jbry8wbPItevOiGtIe?= =?us-ascii?Q?9afJ60beT4uwdYj/Bu1kVb+NbtXlW7CwKU5y9dqp9cyIw0WRuJauyOF+olj2?= =?us-ascii?Q?cvGncuYGaQ1P7Ovq7SSjAE/TgvdJBoBjQOyxFhQocum46rcyA78PQB+XwCZ8?= =?us-ascii?Q?mVW1Y3lhdxrUPGUl90VqsqC4c8OnPRk45tAHuDVgq6JN6p5GIJEb4TvMhWst?= =?us-ascii?Q?i/xPtc5oREmDDKQ3BPMZnmZ/p6IHP9i3rguvFU7yGDBQHHpHvkrFcHmFaPrm?= =?us-ascii?Q?BX0YK3AdtLgw9kImrGWeg6G6bsNlXCrzg0jqWX8Z/mI0fPrHJ1rQT1m++7nf?= =?us-ascii?Q?Xri6XNbeZdjE8YChhihqXicAupUVuT4Oyj0WI8q67NR4a9ttgoLNY1i1nY6F?= =?us-ascii?Q?hJhfG2cz+lT8yKZJNJkBjwAUYrPywHAe7iVOIvdKseinbw9ni8YYUipMxmUV?= =?us-ascii?Q?UCkbFeYqGUin6SnRuzznbzZTX/AzQxyDDqZdOFaL6zOzhKcu8zH4NPQ1CEIe?= =?us-ascii?Q?efI3eLsJOv6hSjdqGDT8vq9eB30w5+/oNKHepJpRjTbCue+OiP0bsbX+idt/?= =?us-ascii?Q?uPkaEKFv8i7eeEz2E+sU01O2bRAXdWWKuHKxuJ3LQ0zcypBcpmsMMo4g6MGR?= =?us-ascii?Q?SARnT99W3i8f0kN75YY+5eaZ5kSR97eNt5ibk00CEOQrTtMxkrMcGso1lgkS?= =?us-ascii?Q?gHGAYPM/8rVxj29Xs6AplYMJOg2PQuLOl/qwgBBE1ND6aHpbJtHRqyVRIZ+W?= =?us-ascii?Q?nfNjjIDeZAExawT6Lot9NYGP+CnbEbqFoIP6hLGifyDkrBbOpYSv0axDhvoj?= =?us-ascii?Q?O8oSu6cNCVHhDmUXhyHf3+scNRExBTF2A1/yQWqRNPz/tmUADpZxhv/GFenE?= =?us-ascii?Q?Umin7ugL7XMY9/q/o65XU+DfLc/o0y+6qtJ0z2MKjaCQ+Hw0swBZEmp9fOcO?= =?us-ascii?Q?MWRo+8gaT/5EOd2Xc6cXAu7Z1h7/RHtODJW9qSeIez9CebEgplLbZO1VMN4j?= =?us-ascii?Q?jFfN101DNvw7BJziVJLCyznJkZbHhSjEpsYv2VTWFvAyt8GraYyhI/hlBNJH?= =?us-ascii?Q?VdUtDO9vFuz9J0zW8Ak++EqZBE35so4XQhP/m6C37vbVnl2GqZKpzWu4Jmp+?= =?us-ascii?Q?zlyAoGhkQv3xa7/oHWpvwyGslbMEtqj5zvZmBL+cEhCkYU8uEhdyUWZ6p2MW?= =?us-ascii?Q?7g=3D=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: a7915380-f8f5-4297-18d4-08daef696d07 X-MS-Exchange-CrossTenant-AuthSource: MWHPR1101MB2126.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Jan 2023 22:08:50.8944 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: BYocwcEYz+Beg/+hR1rvA4bbZurFzNJ9DZ4zc0saB+wLOFFzN3DZUw1+9u1agxfezC9cwdUom8WHFAGRpR5E74dWAz4H7hRNTvumxTsrrnM= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR11MB5149 X-OriginatorOrg: intel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexander Potapenko wrote: > (+ Dan Williams) > (resending with patch context included) > > On Mon, Jul 11, 2022 at 6:27 PM Marco Elver wrote: > > > > On Fri, 1 Jul 2022 at 16:23, Alexander Potapenko wrote: > > > > > > KMSAN adds extra metadata fields to struct page, so it does not fit into > > > 64 bytes anymore. > > > > Does this somehow cause extra space being used in all kernel configs? > > If not, it would be good to note this in the commit message. > > > I actually couldn't verify this on QEMU, because the driver never got loaded. > Looks like this increases the amount of memory used by the nvdimm > driver in all kernel configs that enable it (including those that > don't use KMSAN), but I am not sure how much is that. > > Dan, do you know how bad increasing MAX_STRUCT_PAGE_SIZE can be? Apologies I missed this several months ago. The answer is that this causes everyone creating PMEM namespaces on v6.1+ to lose double the capacity of their namespace even when not using KMSAN which is too wasteful to tolerate. So, I think "6e9f05dc66f9 libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE" needs to be reverted and replaced with something like: diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig index 79d93126453d..5693869b720b 100644 --- a/drivers/nvdimm/Kconfig +++ b/drivers/nvdimm/Kconfig @@ -63,6 +63,7 @@ config NVDIMM_PFN bool "PFN: Map persistent (device) memory" default LIBNVDIMM depends on ZONE_DEVICE + depends on !KMSAN select ND_CLAIM help Map persistent memory, i.e. advertise it to the memory ...otherwise, what was the rationale for increasing this value? Were you actually trying to use KMSAN for DAX pages?