[mirror_ubuntu-bionic-kernel.git] / include / linux / migrate_mode.h

/* SPDX-License-Identifier: GPL-2.0 */
#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 */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
6536e312 AM	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
2916ecc0 JG	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.
6536e312 AM	14	*/
	15	enum migrate_mode {
	16	MIGRATE_ASYNC,
	17	MIGRATE_SYNC_LIGHT,
	18	MIGRATE_SYNC,
2916ecc0	19	MIGRATE_SYNC_NO_COPY,
6536e312 AM	20	};
	21
	22	#endif /* MIGRATE_MODE_H_INCLUDED */