• Rafael J. Wysocki's avatar
    [PATCH] swsusp: Use memory bitmaps during resume · 940864dd
    Rafael J. Wysocki authored
    Make swsusp use memory bitmaps to store its internal information during the
    resume phase of the suspend-resume cycle.
    
    If the pfns of saveable pages are saved during the suspend phase instead of
    the kernel virtual addresses of these pages, we can use them during the resume
    phase directly to set the corresponding bits in a memory bitmap.  Then, this
    bitmap is used to mark the page frames corresponding to the pages that were
    saveable before the suspend (aka "unsafe" page frames).
    
    Next, we allocate as many page frames as needed to store the entire suspend
    image and make sure that there will be some extra free "safe" page frames for
    the list of PBEs constructed later.  Subsequently, the image is loaded and, if
    possible, the data loaded from it are written into their "original" page
    frames (ie.  the ones they had occupied before the suspend).
    
    The image data that cannot be written into their "original" page frames are
    loaded into "safe" page frames and their "original" kernel virtual addresses,
    as well as the addresses of the "safe" pages containing their copies, are
    stored in a list of PBEs.  Finally, the list of PBEs is used to copy the
    remaining image data into their "original" page frames (this is done
    atomically, by the architecture-dependent parts of swsusp).
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    Acked-by: default avatarPavel Machek <pavel@ucw.cz>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    940864dd
user.c 6.79 KB