• Sergey Senozhatsky's avatar
    zram: use notify_free to account all free notifications · 015254da
    Sergey Senozhatsky authored
    `notify_free' device attribute accounts the number of slot free
    notifications and internally represents the number of zram_free_page()
    calls.  Slot free notifications are sent only when device is used as a
    swap device, hence `notify_free' is used only for swap devices.  Since
    f4659d8e (zram: support REQ_DISCARD) ZRAM handles yet another one
    free notification (also via zram_free_page() call) -- REQ_DISCARD
    requests, which are sent by a filesystem, whenever some data blocks are
    discarded.  However, there is no way to know the number of notifications
    in the latter case.
    
    Use `notify_free' to account the number of pages freed by
    zram_bio_discard() and zram_slot_free_notify().  Depending on usage
    scenario `notify_free' represents:
    
     a) the number of pages freed because of slot free notifications, which is
       equal to the number of swap_slot_free_notify() calls, so there is no
       behaviour change
    
     b) the number of pages freed because of REQ_DISCARD notifications
    Signed-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
    Acked-by: default avatarMinchan Kim <minchan@kernel.org>
    Acked-by: default avatarJerome Marchand <jmarchan@redhat.com>
    Cc: Nitin Gupta <ngupta@vflare.org>
    Cc: Chao Yu <chao2.yu@samsung.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    015254da
zram_drv.c 27.4 KB