linux-stable/include/linux/migrate_mode.h
John Hubbard 8eb42beac8 mm/migrate: de-duplicate migrate_reason strings
In order to remove the need to manually keep three different files in
synch, provide a common definition of the mapping between enum
migrate_reason, and the associated strings for each enum item.

1. Use the tracing system's mapping of enums to strings, by redefining
   and reusing the MIGRATE_REASON and supporting macros, and using that
   to populate the string array in mm/debug.c.

2. Move enum migrate_reason to migrate_mode.h. This is not strictly
   necessary for this patch, but migrate mode and migrate reason go
   together, so this will slightly clarify things.

Link: https://lkml.kernel.org/r/20210922041755.141817-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Weizhao Ouyang <o451686892@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:41 -07:00

35 lines
985 B
C

/* 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,
};
enum migrate_reason {
MR_COMPACTION,
MR_MEMORY_FAILURE,
MR_MEMORY_HOTPLUG,
MR_SYSCALL, /* also applies to cpusets */
MR_MEMPOLICY_MBIND,
MR_NUMA_MISPLACED,
MR_CONTIG_RANGE,
MR_LONGTERM_PIN,
MR_DEMOTION,
MR_TYPES
};
#endif /* MIGRATE_MODE_H_INCLUDED */