Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754095AbXJHQyy (ORCPT ); Mon, 8 Oct 2007 12:54:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751863AbXJHQyq (ORCPT ); Mon, 8 Oct 2007 12:54:46 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:52052 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751504AbXJHQyq (ORCPT ); Mon, 8 Oct 2007 12:54:46 -0400 Subject: [PATCH] mm: set_page_dirty_balance() vs ->page_mkwrite() From: Peter Zijlstra To: linux-kernel , Linus Torvalds , Andrew Morton Cc: Christoph Hellwig , David Howells , Nick Piggin , Dave Chinner , Trond Myklebust , mark.fasheh@oracle.com, hugh , stable Content-Type: text/plain Date: Mon, 08 Oct 2007 18:54:37 +0200 Message-Id: <1191862477.20745.22.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3806 Lines: 119 It seems that with the recent usage of ->page_mkwrite() a little detail was overlooked. .22-rc1 merged OCFS2 usage of this hook .23-rc1 merged XFS usage .24-rc1 will most likely merge NFS usage Please consider this for .23 final and maybe even .22.x --- Subject: mm: set_page_dirty_balance() vs ->page_mkwrite() All the current page_mkwrite() implementations also set the page dirty. Which results in the set_page_dirty_balance() call to _not_ call balance, because the page is already found dirty. This allows us to dirty a _lot_ of pages without ever hitting balance_dirty_pages(). Not good (tm). Force a balance call if ->page_mkwrite() was successful. Signed-off-by: Peter Zijlstra --- include/linux/writeback.h | 2 +- mm/memory.c | 9 +++++++-- mm/page-writeback.c | 4 ++-- 3 files changed, 10 insertions(+), 5 deletions(-) Index: linux-2.6/include/linux/writeback.h =================================================================== --- linux-2.6.orig/include/linux/writeback.h +++ linux-2.6/include/linux/writeback.h @@ -137,7 +137,7 @@ int sync_page_range(struct inode *inode, loff_t pos, loff_t count); int sync_page_range_nolock(struct inode *inode, struct address_space *mapping, loff_t pos, loff_t count); -void set_page_dirty_balance(struct page *page); +void set_page_dirty_balance(struct page *page, int page_mkwrite); void writeback_set_ratelimit(void); /* pdflush.c */ Index: linux-2.6/mm/memory.c =================================================================== --- linux-2.6.orig/mm/memory.c +++ linux-2.6/mm/memory.c @@ -1559,6 +1559,7 @@ static int do_wp_page(struct mm_struct * struct page *old_page, *new_page; pte_t entry; int reuse = 0, ret = 0; + int page_mkwrite = 0; struct page *dirty_page = NULL; old_page = vm_normal_page(vma, address, orig_pte); @@ -1607,6 +1608,8 @@ static int do_wp_page(struct mm_struct * page_cache_release(old_page); if (!pte_same(*page_table, orig_pte)) goto unlock; + + page_mkwrite = 1; } dirty_page = old_page; get_page(dirty_page); @@ -1691,7 +1694,7 @@ unlock: * do_no_page is protected similarly. */ wait_on_page_locked(dirty_page); - set_page_dirty_balance(dirty_page); + set_page_dirty_balance(dirty_page, page_mkwrite); put_page(dirty_page); } return ret; @@ -2238,6 +2241,7 @@ static int __do_fault(struct mm_struct * struct page *dirty_page = NULL; struct vm_fault vmf; int ret; + int page_mkwrite = 0; vmf.virtual_address = (void __user *)(address & PAGE_MASK); vmf.pgoff = pgoff; @@ -2315,6 +2319,7 @@ static int __do_fault(struct mm_struct * anon = 1; /* no anon but release vmf.page */ goto out; } + page_mkwrite = 1; } } @@ -2375,7 +2380,7 @@ out_unlocked: if (anon) page_cache_release(vmf.page); else if (dirty_page) { - set_page_dirty_balance(dirty_page); + set_page_dirty_balance(dirty_page, page_mkwrite); put_page(dirty_page); } Index: linux-2.6/mm/page-writeback.c =================================================================== --- linux-2.6.orig/mm/page-writeback.c +++ linux-2.6/mm/page-writeback.c @@ -460,9 +460,9 @@ static void balance_dirty_pages(struct a pdflush_operation(background_writeout, 0); } -void set_page_dirty_balance(struct page *page) +void set_page_dirty_balance(struct page *page, int page_mkwrite) { - if (set_page_dirty(page)) { + if (set_page_dirty(page) || page_mkwrite) { struct address_space *mapping = page_mapping(page); if (mapping) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/