• Mel Gorman's avatar
    mm: compaction: introduce sync-light migration for use by compaction · a6bc32b8
    Mel Gorman authored
    This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
    mode that avoids writing back pages to backing storage.  Async compaction
    maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT.
    For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is
    This avoids sync compaction stalling for an excessive length of time,
    particularly when copying files to a USB stick where there might be a
    large number of dirty pages backed by a filesystem that does not support
    [aarcange@redhat.com: This patch is heavily based on Andrea's work]
    [akpm@linux-foundation.org: fix fs/nfs/write.c build]
    [akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build]
    Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
    Reviewed-by: default avatarRik van Riel <riel@redhat.com>
    Cc: Andrea Arcangeli <aarcange@redhat.com>
    Cc: Minchan Kim <minchan.kim@gmail.com>
    Cc: Dave Jones <davej@redhat.com>
    Cc: Jan Kara <jack@suse.cz>
    Cc: Andy Isaacson <adi@hexapodia.org>
    Cc: Nai Xia <nai.xia@gmail.com>
    Cc: Johannes Weiner <jweiner@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
memory_hotplug.c 23.9 KB