LXR linux/include/linux/migrate

   1#ifndef MIGRATE_MODE_H_INCLUDED
   2#define MIGRATE_MODE_H_INCLUDED
   3/*
   4 * MIGRATE_ASYNC means never block
   5 * MIGRATE_SYNC_LIGHT in the current implementation means to allow blocking
   6 *      on most operations but not ->writepage as the potential stall time
   7 *      is too significant
   8 * MIGRATE_SYNC will block when migrating pages
   9 * MIGRATE_SYNC_NO_COPY will block when migrating pages but will not copy pages
  10 *      with the CPU. Instead, page copy happens outside the migratepage()
  11 *      callback and is likely using a DMA engine. See migrate_vma() and HMM
  12 *      (mm/hmm.c) for users of this mode.
  13 */
  14enum migrate_mode {
  15        MIGRATE_ASYNC,
  16        MIGRATE_SYNC_LIGHT,
  17        MIGRATE_SYNC,
  18};
  19
  20#define MIGRATE_SYNC_NO_COPY (MIGRATE_SYNC + 1)
  21
  22#endif          /* MIGRATE_MODE_H_INCLUDED */
  23