OpenCloudOS-Kernel/include/linux/migrate_mode.h

22 lines
719 B
C

#ifndef MIGRATE_MODE_H_INCLUDED
#define MIGRATE_MODE_H_INCLUDED
/*
* MIGRATE_ASYNC means never block
* MIGRATE_SYNC_LIGHT in the current implementation means to allow blocking
* on most operations but not ->writepage as the potential stall time
* is too significant
* MIGRATE_SYNC will block when migrating pages
* MIGRATE_SYNC_NO_COPY will block when migrating pages but will not copy pages
* with the CPU. Instead, page copy happens outside the migratepage()
* callback and is likely using a DMA engine. See migrate_vma() and HMM
* (mm/hmm.c) for users of this mode.
*/
enum migrate_mode {
MIGRATE_ASYNC,
MIGRATE_SYNC_LIGHT,
MIGRATE_SYNC,
MIGRATE_SYNC_NO_COPY,
};
#endif /* MIGRATE_MODE_H_INCLUDED */