From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 27 Oct 2005 11:20:54 -0700 From: Andrew Morton Subject: Re: [RFC] madvise(MADV_TRUNCATE) Message-Id: <20051027112054.10e945ae.akpm@osdl.org> In-Reply-To: <20051027151123.GO5091@opteron.random> References: <1130366995.23729.38.camel@localhost.localdomain> <200510271038.52277.ak@suse.de> <20051027131725.GI5091@opteron.random> <1130425212.23729.55.camel@localhost.localdomain> <20051027151123.GO5091@opteron.random> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: pbadari@us.ibm.com, ak@suse.de, hugh@veritas.com, jdike@addtoit.com, dvhltc@us.ibm.com, linux-mm@kvack.org List-ID: err, guys. Andrea Arcangeli wrote: > > ... > > tmpfs (the short term big need of this feature). > > ... > > Freeing swap entries is the most important thing and at the same time > the most complex in the patch (that's why the previous MADV_DISCARD was > so simple ;). > I think there's something you're not telling us! googling MADV_DISCARD comes up with basically nothing. MADV_TRUNCATE comes up with precisely nothing. Why does tmpfs need this feature? What's the requirement here? Please spill the beans ;) Comment on the patch: doing it via madvise sneakily gets around the problems with partial-page truncation (we don't currently have a way to release anything but the the tail-end of a page's blocks). But if we start adding infrastructure of this sort people are, reasonably, going to want to add sys_holepunch(fd, start, len) and it's going to get complexer. -- 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