From: Andrew Morton Date: Thu, 9 May 2013 23:57:17 +0000 (+1000) Subject: mm-remove-compressed-copy-from-zram-in-memory-fix X-Git-Tag: next-20130521~1^2~139 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=bfe482ae01d4ad6a4352d366e0b2dcd26fb2319d;p=karo-tx-linux.git mm-remove-compressed-copy-from-zram-in-memory-fix tweak comment text Cc: Dan Magenheimer Cc: Hugh Dickins Cc: Konrad Rzeszutek Wilk Cc: Minchan Kim Cc: Nitin Gupta Cc: Seth Jennings Cc: Shaohua Li Signed-off-by: Andrew Morton --- diff --git a/mm/page_io.c b/mm/page_io.c index 736ffac48030..1897abb8fdf6 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -88,20 +88,20 @@ void end_swap_bio_read(struct bio *bio, int err) sis = page_swap_info(page); if (sis->flags & SWP_BLKDEV) { /* - * Swap subsystem does lazy swap slot free with - * expecting the page would be swapped out again - * so we can avoid unnecessary write if the page - * isn't redirty. - * It's good for real swap storage because we can + * The swap subsystem performs lazy swap slot freeing, + * expecting that the page will be swapped out again. + * So we can avoid an unnecessary write if the page + * isn't redirtied. + * This is good for real swap storage because we can * reduce unnecessary I/O and enhance wear-leveling - * if you use SSD as swap device. - * But if you use in-memory swap device(ex, zram), - * it causes duplicated copy between uncompressed + * if an SSD is used as the as swap device. + * But if in-memory swap device (eg zram) is used, + * this causes a duplicated copy between uncompressed * data in VM-owned memory and compressed data in - * zram-owned memory. So let's free zram-owned memory - * and make the VM-owned decompressed page *dirty* - * so the page should be swap out somewhere again if - * we want to reclaim it, again. + * zram-owned memory. So let's free zram-owned memory + * and make the VM-owned decompressed page *dirty*, + * so the page should be swapped out somewhere again if + * we again wish to reclaim it. */ struct gendisk *disk = sis->bdev->bd_disk; if (disk->fops->swap_slot_free_notify) {