From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 31 Jan 2007 19:17:54 +0000 (GMT) From: Hugh Dickins Subject: Re: [patch] simplify shmem_aops.set_page_dirty method In-Reply-To: <20070131111146.2b29d851.akpm@osdl.org> Message-ID: References: <20070131111146.2b29d851.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Ken Chen , linux-mm@kvack.org List-ID: On Wed, 31 Jan 2007, Andrew Morton wrote: > On Wed, 31 Jan 2007 17:17:10 +0000 (GMT) Hugh Dickins wrote: > > > 2. Please remind me what good __mark_inode_dirty will do for shmem: > > None that I can think of - tmpfs inodes don't get written back to swap (do > they?) That's right, tmpfs inodes are only in RAM, only the data can go to swap. > > > in my patch the equivalent function did nothing beyond SetPageDirty > > (your TestSetPageDirty looks better, less redirtying the cacheline). > > Will test_and_set_bit() avoid dirtying the cacheline? I guess it _could_ > do this, and perhaps this depends upon the architecture. Perhaps > > if (!PageDirty(page)) > SetPageDirty(page); > > would be better here. Synchronicity or telepathy? Our mails on that crossed. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org