From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <419D4EC7.6020100@yahoo.com.au> Date: Fri, 19 Nov 2004 12:39:19 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: another approach to rss : sloppy rss References: <419D47E6.8010409@yahoo.com.au> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Hugh Dickins , Benjamin Herrenschmidt , linux-mm@kvack.org, linux-ia64@kernel.vger.org List-ID: Christoph Lameter wrote: > On Fri, 19 Nov 2004, Nick Piggin wrote: > > >>>The patch insures that negative rss values are not displayed and removes 3 >>>checks in mm/rmap.c that utilized rss (unecessarily AFAIK). >> >>I wonder if your lazy rss counting still has a place? You still have >>a shared cacheline with sloppy rss. But is it significantly better >>for you just by using unlocked instructions... > > > Right. The fetchadd for atomic increments really bites here. > > Got an enhanced lazy rss patch here but it got so much opposition and then > I discovered that one of our other projects here at SGI depends on > realtime rss. > What do you think a per-mm flag to switch between realtime and lazy rss? The only code it would really _add_ would be your mm counting function... I guess another couple of branches in the fault handlers too, but I don't know if they'd be very significant. -- 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: aart@kvack.org