• Mel Gorman's avatar
    mm: vmscan: do not writeback filesystem pages in kswapd except in high priority · f84f6e2b
    Mel Gorman authored
    It is preferable that no dirty pages are dispatched for cleaning from the
    page reclaim path.  At normal priorities, this patch prevents kswapd
    writing pages.
    However, page reclaim does have a requirement that pages be freed in a
    particular zone.  If it is failing to make sufficient progress (reclaiming
    < SWAP_CLUSTER_MAX at any priority priority), the priority is raised to
    scan more pages.  A priority of DEF_PRIORITY - 3 is considered to be the
    point where kswapd is getting into trouble reclaiming pages.  If this
    priority is reached, kswapd will dispatch pages for writing.
    Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
    Reviewed-by: default avatarMinchan Kim <minchan.kim@gmail.com>
    Cc: Dave Chinner <david@fromorbit.com>
    Cc: Christoph Hellwig <hch@infradead.org>
    Cc: Johannes Weiner <jweiner@redhat.com>
    Cc: Wu Fengguang <fengguang.wu@intel.com>
    Cc: Jan Kara <jack@suse.cz>
    Cc: Rik van Riel <riel@redhat.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Cc: Alex Elder <aelder@sgi.com>
    Cc: Theodore Ts'o <tytso@mit.edu>
    Cc: Chris Mason <chris.mason@oracle.com>
    Cc: Dave Hansen <dave@linux.vnet.ibm.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
vmscan.c 97.2 KB