From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 4950B6B0044 for ; Fri, 19 Dec 2008 02:34:14 -0500 (EST) Date: Thu, 18 Dec 2008 23:35:49 -0800 From: Andrew Morton Subject: Re: [rfc][patch] unlock_page speedup Message-Id: <20081218233549.cb451bc8.akpm@linux-foundation.org> In-Reply-To: <20081219072909.GC26419@wotan.suse.de> References: <20081219072909.GC26419@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Nick Piggin Cc: Linux Memory Management List , linux-fsdevel@vger.kernel.org, Linus Torvalds List-ID: On Fri, 19 Dec 2008 08:29:09 +0100 Nick Piggin wrote: > Introduce a new page flag, PG_waiters Leaving how many? fs-cache wants to take two more. How's about we actually work this out, then make PG_waiters the highest-numbered free one? PG_free1, PG_free2, ... PG_waiters }; (or even something really sensitive, like PG_lru) So that a) we can see how many are left in a robust fashion and b) we find out whether PG_waiters (PG_lru?) gets scribbled on by architectures which borrow upper bits from page.flags for other nefarious purposes. ? -- 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