1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef MIGRATE_MODE_H_INCLUDED
3 #define MIGRATE_MODE_H_INCLUDED
4 /*
5 * MIGRATE_ASYNC means never block
6 * MIGRATE_SYNC_LIGHT in the current implementation means to allow blocking
7 * on most operations but not ->writepage as the potential stall time
8 * is too significant
9 * MIGRATE_SYNC will block when migrating pages
10 * MIGRATE_SYNC_NO_COPY will block when migrating pages but will not copy pages
11 * with the CPU. Instead, page copy happens outside the migratepage()
12 * callback and is likely using a DMA engine. See migrate_vma() and HMM
13 * (mm/hmm.c) for users of this mode.
14 */
15 enum migrate_mode {
16 MIGRATE_ASYNC,
17 MIGRATE_SYNC_LIGHT,
18 MIGRATE_SYNC,
19 MIGRATE_SYNC_NO_COPY,
20 };
21
22 #endif /* MIGRATE_MODE_H_INCLUDED */