Eric Lee / smarc-ti-linux-kernel

12 Sep, 2013

1 commit

01 Aug, 2013

1 commit

  • 9d8c5b528   mm: zbud: fix condition check on allocation size ... Browse Code »

    zbud_alloc() incorrectly verifies the size of allocation limit. It
    should deny the allocation request greater than (PAGE_SIZE -
    ZHDR_SIZE_ALIGNED - CHUNK_SIZE), not (PAGE_SIZE - ZHDR_SIZE_ALIGNED)
    which has no remaining spaces for its buddy. There is no point in
    spending the entire zbud page storing only a single page, since we don't
    have any benefits.

    Signed-off-by: Heesub Shin
    Acked-by: Seth Jennings
    Cc: Bob Liu
    Cc: Dongjun Shin
    Cc: Sunae Seo
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Heesub Shin
     

11 Jul, 2013

1 commit

  • 4e2e2770b   zbud: add to mm/ ... Browse Code »

    zbud is an special purpose allocator for storing compressed pages. It
    is designed to store up to two compressed pages per physical page.
    While this design limits storage density, it has simple and
    deterministic reclaim properties that make it preferable to a higher
    density approach when reclaim will be used.

    zbud works by storing compressed pages, or "zpages", together in pairs
    in a single memory page called a "zbud page". The first buddy is "left
    justifed" at the beginning of the zbud page, and the last buddy is
    "right justified" at the end of the zbud page. The benefit is that if
    either buddy is freed, the freed buddy space, coalesced with whatever
    slack space that existed between the buddies, results in the largest
    possible free region within the zbud page.

    zbud also provides an attractive lower bound on density. The ratio of
    zpages to zbud pages can not be less than 1. This ensures that zbud can
    never "do harm" by using more pages to store zpages than the
    uncompressed zpages would have used on their own.

    This implementation is a rewrite of the zbud allocator internally used
    by zcache in the driver/staging tree. The rewrite was necessary to
    remove some of the zcache specific elements that were ingrained
    throughout and provide a generic allocation interface that can later be
    used by zsmalloc and others.

    This patch adds zbud to mm/ for later use by zswap.

    Signed-off-by: Seth Jennings
    Acked-by: Rik van Riel
    Cc: Greg Kroah-Hartman
    Cc: Nitin Gupta
    Cc: Minchan Kim
    Cc: Konrad Rzeszutek Wilk
    Cc: Dan Magenheimer
    Cc: Robert Jennings
    Cc: Jenifer Hopper
    Cc: Mel Gorman
    Cc: Johannes Weiner
    Cc: Larry Woodman
    Cc: Benjamin Herrenschmidt
    Cc: Dave Hansen
    Cc: Joe Perches
    Cc: Joonsoo Kim
    Cc: Cody P Schafer
    Cc: Hugh Dickens
    Cc: Paul Mackerras
    Cc: Bob Liu
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Seth Jennings