From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from detritus.pyropus.ca ([64.5.53.58]:52859 "HELO detritus.pyropus.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751637AbaLYDJ4 (ORCPT ); Wed, 24 Dec 2014 22:09:56 -0500 Date: Wed, 24 Dec 2014 21:14:13 -0600 From: Charles Cazabon To: btrfs list Subject: Re: Oddly slow read performance with near-full largish FS Message-ID: <20141225031413.GA5864@pyropus.ca> References: <20141217024228.GA5544@pyropus.ca> <54955624.5040808@pobox.com> <20141221163207.GA18988@pyropus.ca> <54973C65.6070709@pobox.com> <20141221225315.GA19479@pyropus.ca> <54976811.2060507@pobox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <54976811.2060507@pobox.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Robert White wrote: > > You have very little free memory. I think you're mistaken. Every diagnostic I've looked at says the opposite. >>From 30 seconds ago on the same machine, after unmounting the big btrfs filesystem (and with a larger xfs one mounted), /proc/meminfo says almost the entirety of the machine's 16GB is free: MemTotal: 16469880 kB MemFree: 16005392 kB MemAvailable: 15974244 kB Buffers: 84 kB [...] > This is called "demand paging", Yes, I'm aware of how this works. Charles -- ----------------------------------------------------------------------- Charles Cazabon GPL'ed software available at: http://pyropus.ca/software/ -----------------------------------------------------------------------