I copy description of 1/5. Now we add page reference on add_to_page_cache but doesn't drop it in remove_from_page_cache. Such asymmetric makes confusing about page reference so that caller should notice it and comment why they release page reference. It's not good API. Long time ago, Hugh tried it[1] but gave up of reason which reiser4's drop_page had to unlock the page between removing it from page cache and doing the page_cache_release. But now the situation is changed. I think at least things in current mainline doesn't have any obstacles. The problem is fs or somethings out of mainline. If it has done such thing like reiser4, this patch could be a problem. Do anyone know the such things? Do we care about things out of mainline? [1] http://lkml.org/lkml/2004/10/24/140 Minchan Kim (5): drop page reference on remove_from_page_cache fuse: Remove unnecessary page release tlbfs: Remove unnecessary page release swap: Remove unnecessary page release truncate: Remove unnecessary page release fs/fuse/dev.c | 1 - fs/hugetlbfs/inode.c | 1 - mm/filemap.c | 12 ++++++++++++ mm/shmem.c | 1 - mm/truncate.c | 1 - 5 files changed, 12 insertions(+), 4 deletions(-) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>