From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 25 Jul 2007 13:50:12 +0200 From: Ingo Molnar Subject: Re: -mm merge plans for 2.6.23 Message-ID: <20070725115012.GB27498@elte.hu> References: <46A6CC56.6040307@yahoo.com.au> <46A6D7D2.4050708@gmail.com> <46A6DFFD.9030202@gmail.com> <30701.1185347660@turing-police.cc.vt.edu> <46A7074B.50608@gmail.com> <20070725082822.GA13098@elte.hu> <46A70D37.3060005@gmail.com> <20070725113401.GA23341@elte.hu> <46A736C9.4090701@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46A736C9.4090701@gmail.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Rene Herman Cc: Valdis.Kletnieks@vt.edu, david@lang.hm, Nick Piggin , Ray Lee , Jesper Juhl , Andrew Morton , ck list , Paul Jackson , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: * Rene Herman wrote: > > and the fact is: updatedb discards a considerable portion of the > > cache completely unnecessarily: on a reasonably complex box no way > > do all the inodes and dentries fit into all of RAM, so we just trash > > everything. > > Okay, but unless I've now managed to really quite horribly confuse > myself, that wouldn't have anything to do with _swap_ prefetch would > it? it's connected: it would remove updatedb from the VM picture altogether. (updatedb would just cycle through the files with leaving minimal cache disturbance.) hence swap-prefetch could concentrate on the cases where it makes sense to start swap prefetching _without_ destroying other, already cached content: such as when a large app exits and frees gobs of memory back into the buddy allocator. _That_ would be a definitive "no costs and side-effects" point for swap-prefetch to kick in, and it would eliminate this pretty artificial (and unnecessary) 'desktop versus server' controversy and would turn it into a 'helps everyone' feature. Ingo -- 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