From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 31 Jul 2006 19:34:27 +0100 (BST) From: Hugh Dickins Subject: Re: [patch 2/2] mm: lockless pagecache In-Reply-To: <44CE2365.6040605@shadowen.org> Message-ID: References: <20060726063941.GB32107@wotan.suse.de> <44CE2365.6040605@shadowen.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andy Whitcroft Cc: Nick Piggin , Andrew Morton , Linux Memory Management List List-ID: On Mon, 31 Jul 2006, Andy Whitcroft wrote: > > Index: linux-2.6/mm/filemap.c > > =================================================================== > > --- linux-2.6.orig/mm/filemap.c > > +++ linux-2.6/mm/filemap.c > > @@ -613,11 +613,22 @@ struct page *find_trylock_page(struct ad > .... > > This one has me puzzled. This seem to no longer lock the page at all when > returning it. It seems the semantics of this has changed wildly. Also > find_lock_page below still seems to lock the page, the semantic seems > maintained there? I think I am expecting to find a TestSetPageLocked() > in the new version too? Whereas find_get_page, which should be the centre-piece of the patch, is unchanged and using read_lock_irq(&mapping->tree_lock) as before. It looks like the code seen in find_trylock_page is actually what should be in find_get_page. It doesn't matter too much what find_trylock_page does, since it's deprecated and nothing in tree now uses it; but it ought to TestSetPageLocked and page_cache_release somewhere, to suit remaining out-of-tree users. 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