From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFT][PATCH] mm: drop behind From: Peter Zijlstra In-Reply-To: References: <1184007008.1913.45.camel@twins> Content-Type: text/plain Date: Thu, 12 Jul 2007 09:24:46 +0200 Message-Id: <1184225086.20032.45.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Tim Pepper Cc: linux-kernel , linux-mm , Fengguang Wu , riel , Andrew Morton , Rusty Russell List-ID: Hi Tim, On Wed, 2007-07-11 at 15:37 -0700, Tim Pepper wrote: > On 7/9/07, Peter Zijlstra wrote: > > Use the read-ahead code to provide hints to page reclaim. > > > > This patch has the potential to solve the streaming-IO trashes my > > desktop problem. > > > > It tries to aggressively reclaim pages that were loaded in a strong > > sequential pattern and have been consumed. Thereby limiting the damage > > to the current resident set. > > Interesting... > > Would it make sense to tie this into (finally) making > POSIX_FADV_NOREUSE something more than a noop? We talked about that, but the thing is, if we make the functionality conditional, nobody will ever use it :-/ So, yes, in a perfect world that would indeed make sense. However since nobody ever uses these [fm]advise calls,.. So the big question is, does this functionally hurt any workload? If it turns out it does (which I still doubt) then we might hide it behind knobs, otherwise I'd like to keep it always on. Peter -- 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