Unverified Commit a99d34e5 authored by Thomas Hellström's avatar Thomas Hellström Committed by Rodrigo Vivi
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Revert "drm/pagemap: Disable device-to-device migration" 



With commit
a69d1ab9 ("mm: Fix a hmm_range_fault() livelock / starvation problem")
device-to-device migration is not functional again and the
disabling can be reverted.

Add the above commit as a Fixes: tag in order for the revert to not
take place unless that commit is present.

This reverts commit 10dd1eaa.

Cc: Matthew Brost <matthew.brost@intel.com>
Fixes: b570f37a ("mm: Fix a hmm_range_fault() livelock / starvation problem")
Signed-off-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260211104159.114947-1-thomas.hellstrom@linux.intel.com


(cherry picked from commit 1a3c0049)
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
[Rodrigo updated Fixes tag]
parent b570f37a

drivers/gpu/drm/drm_pagemap.c

+2 −12
Original line number Diff line number Diff line
@@ -480,18 +480,8 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation, 
		.start		= start,

		.end		= end,

		.pgmap_owner	= pagemap->owner,

		/*

		 * FIXME: MIGRATE_VMA_SELECT_DEVICE_PRIVATE intermittently

		 * causes 'xe_exec_system_allocator --r *race*no*' to trigger aa

		 * engine reset and a hard hang due to getting stuck on a folio

		 * lock. This should work and needs to be root-caused. The only

		 * downside of not selecting MIGRATE_VMA_SELECT_DEVICE_PRIVATE

		 * is that device-to-device migrations won’t work; instead,

		 * memory will bounce through system memory. This path should be

		 * rare and only occur when the madvise attributes of memory are

		 * changed or atomics are being used.

		 */

		.flags		= MIGRATE_VMA_SELECT_SYSTEM | MIGRATE_VMA_SELECT_DEVICE_COHERENT,

		.flags		= MIGRATE_VMA_SELECT_SYSTEM | MIGRATE_VMA_SELECT_DEVICE_COHERENT |

		MIGRATE_VMA_SELECT_DEVICE_PRIVATE,

	};

	unsigned long i, npages = npages_in_range(start, end);

	unsigned long own_pages = 0, migrated_pages = 0;