On Thu, 23 Dec 2010, Minchan Kim wrote: > Now we increases page reference on add_to_page_cache but doesn't decrease 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 but > they found it when compile time since we remove remove_from_page_cache. > > [1] http://lkml.org/lkml/2004/10/24/140 > > The series configuration is following as. > > [1/7] : This patch introduces new API delete_from_page_cache. > [2,3,4,5/7] : Change remove_from_page_cache with delete_from_page_cache. > Intentionally I divide patch per file since someone might have a concern > about releasing page reference of delete_from_page_cache in > somecase (ex, truncate.c) > [6/7] : Remove old API so out of fs can meet compile error when build time > and can notice it. > [7/7] : Change __remove_from_page_cache with __delete_from_page_cache, too. > In this time, I made all-in-one patch because it doesn't change old behavior > so it has no concern. Just clean up patch. > > Minchan Kim (7): > [1/7] Introduce delete_from_page_cache > [2/7] fuse: Change remove_from_page_cache > [3/7] tlbfs: Change remove_from_page_cache > [4/7] swap: Change remove_from_page_cache > [5/7] truncate: Change remove_from_page_cache > [6/7] Good bye remove_from_page_cache > [7/7] Change __remove_from_page_cache > > fs/fuse/dev.c | 3 +-- > fs/hugetlbfs/inode.c | 3 +-- > include/linux/pagemap.h | 4 ++-- > mm/filemap.c | 22 +++++++++++++++++----- > mm/shmem.c | 3 +-- > mm/truncate.c | 5 ++--- > mm/vmscan.c | 2 +- > 7 files changed, 25 insertions(+), 17 deletions(-) Acked-by: Hugh Dickins <hughd@xxxxxxxxxx> for all seven: thanks. -- 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>