The patch titled mm: clean up page_remove_rmap() has been added to the -mm tree. Its filename is mm-clean-up-page_remove_rmap.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mm: clean up page_remove_rmap() From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> page_remove_rmap() has multiple PageAnon() tests and it has deep nesting. Clean this up. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Acked-by: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/rmap.c | 57 +++++++++++++++++++++++++++------------------------- 1 file changed, 30 insertions(+), 27 deletions(-) diff -puN mm/rmap.c~mm-clean-up-page_remove_rmap mm/rmap.c --- a/mm/rmap.c~mm-clean-up-page_remove_rmap +++ a/mm/rmap.c @@ -738,34 +738,37 @@ void page_dup_rmap(struct page *page, st */ void page_remove_rmap(struct page *page) { - if (atomic_add_negative(-1, &page->_mapcount)) { - /* - * Now that the last pte has gone, s390 must transfer dirty - * flag from storage key to struct page. We can usually skip - * this if the page is anon, so about to be freed; but perhaps - * not if it's in swapcache - there might be another pte slot - * containing the swap entry, but page not yet written to swap. - */ - if ((!PageAnon(page) || PageSwapCache(page)) && - page_test_dirty(page)) { - page_clear_dirty(page); - set_page_dirty(page); - } - if (PageAnon(page)) - mem_cgroup_uncharge_page(page); - __dec_zone_page_state(page, - PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED); - mem_cgroup_update_mapped_file_stat(page, -1); - /* - * It would be tidy to reset the PageAnon mapping here, - * but that might overwrite a racing page_add_anon_rmap - * which increments mapcount after us but sets mapping - * before us: so leave the reset to free_hot_cold_page, - * and remember that it's only reliable while mapped. - * Leaving it set also helps swapoff to reinstate ptes - * faster for those pages still in swapcache. - */ + /* page still mapped by someone else? */ + if (!atomic_add_negative(-1, &page->_mapcount)) + return; + + /* + * Now that the last pte has gone, s390 must transfer dirty + * flag from storage key to struct page. We can usually skip + * this if the page is anon, so about to be freed; but perhaps + * not if it's in swapcache - there might be another pte slot + * containing the swap entry, but page not yet written to swap. + */ + if ((!PageAnon(page) || PageSwapCache(page)) && page_test_dirty(page)) { + page_clear_dirty(page); + set_page_dirty(page); + } + if (PageAnon(page)) { + mem_cgroup_uncharge_page(page); + __dec_zone_page_state(page, NR_ANON_PAGES); + } else { + __dec_zone_page_state(page, NR_FILE_MAPPED); } + mem_cgroup_update_mapped_file_stat(page, -1); + /* + * It would be tidy to reset the PageAnon mapping here, + * but that might overwrite a racing page_add_anon_rmap + * which increments mapcount after us but sets mapping + * before us: so leave the reset to free_hot_cold_page, + * and remember that it's only reliable while mapped. + * Leaving it set also helps swapoff to reinstate ptes + * faster for those pages still in swapcache. + */ } /* _ Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are linux-next.patch readahead-add-blk_run_backing_dev.patch readahead-add-blk_run_backing_dev-fix.patch readahead-add-blk_run_backing_dev-fix-fix-2.patch vmscan-dont-attempt-to-reclaim-anon-page-in-lumpy-reclaim-when-no-swap-space-is-available.patch mm-clean-up-page_remove_rmap.patch getrusage-fill-ru_maxrss-value.patch getrusage-fill-ru_maxrss-value-update.patch fs-symlink-write_begin-allocation-context-fix-reiser4-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html