From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 22 Oct 2002 20:43:13 +0200 From: bert hubert Subject: vm scenario tool / mincore(2) functionality for regular pages? Message-ID: <20021022184313.GA12081@outpost.ds9a.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org List-ID: I'm building a tool to subject the VM to different scenarios and I'd like to be able to determine if a page is swapped out or not. For a file I can easily determine if a page is in memory (in the page cache) or not using the mincore(2) system call. I want to expand my tool so it can investigate which of its pages are swapped out under cache pressure or real memory pressure. However, to do this, I need a way to determine if a page is there or if it is swapped out. My two questions are: 1) is there an existing way to do this (the kernel obviously knows) 2) would it be correct to expand mincore to also work on non-filebacked memory so it works for 'swap-backed' memory too? Thanks. Some current output of the scenario tool: vmloader> alloc 25 Arena now 25 megabytes, 6250 pages vmloader> sweep Sweeping from mbyte 0 to 25, 6250 pages. Done vmloader> rusage minor: 6250, major: 2, swaps: 0 vmloader> sweep 0 12 Sweeping from mbyte 0 to 12, 1440 pages. Done vmloader> rusage minor: 0, major: 0, swaps: 0 vmloader> touch Touching from mbyte 0 to 25, 6250 pages. Done vmloader> rusage minor: 6249, major: 0, swaps: 0 vmloader> rsweep Random sweeping from mbyte 0 to 25, 6250 pages. Done vmloader> rusage minor: 0, major: 0, swaps: 0 -- http://www.PowerDNS.com Versatile DNS Software & Services http://lartc.org Linux Advanced Routing & Traffic Control HOWTO -- 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/