From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 29 Nov 2006 20:13:44 -0800 (PST) From: Christoph Lameter Subject: Re: [RFC][PATCH 1/1] Expose per-node reclaim and migration to userspace In-Reply-To: <6599ad830611291357w34f9427bje775dfefcd000dfa@mail.gmail.com> Message-ID: References: <20061129030655.941148000@menage.corp.google.com> <20061129033826.268090000@menage.corp.google.com> <456D23A0.9020008@yahoo.com.au> <6599ad830611291357w34f9427bje775dfefcd000dfa@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Menage Cc: Nick Piggin , linux-mm@kvack.org, akpm@osdl.org List-ID: On Wed, 29 Nov 2006, Paul Menage wrote: > Quite possibly - I don't have a strong feeling for exactly where the > code should go. There's existing code (sys_migrate_pages) that uses > the migration mechanism that's in mm/mempolicy.c rather than > migrate.c, and this was a pretty simple function to write. Plus there is another mechanism in mm/migrate.c that also uses the migration mechanism. > We don't need to expose the raw "priority" value, but it would be > really nice for user space to be able to specify how hard the kernel > should try to free some memory. Would it not be sufficient to specify that in the number of attempts like already provided by the page migration scheme? > Then each job can specify a "reclaim pressure", i.e. how much > back-pressure should be applied to its allocated memory, so you can > get a good idea of how much memory the job is really using for a given > level of performance. High reclaim pressure results in a smaller > working set but possibly more paging in from disk; low reclaim > pressure uses more memory but gets higher performance. Reclaim? I thought you wanted to migrate memory of a node? -- 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