linux_dsm_epyc7002/include/linux/migrate_mode.h

#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 */