From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] [Request for inclusion] Filesystem in Userspace Date: Wed, 15 Dec 2004 19:45:56 +0200 Message-ID: <41C07854.7000603@argo.co.il> References: <41ACE816.50104@argo.co.il> <200412031707.46114.phillips@istop.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: To: Daniel Phillips In-Reply-To: <200412031707.46114.phillips@istop.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Daniel Phillips wrote: >Hi Avi, > >On Tuesday 30 November 2004 16:37, Avi Kivity wrote: > > >>The situation with userspace filesystems is: >> >> some process allocates memory, blocking on kswapd as memory is full >> kswapd calls userspace filesystem to free memory >> userspace filesystem calls kernel, which allocates memory and blocks >>on kswapd >> eventually all processes in the system block on kswapd >> >>I have observed (and fixed) this on a real system. >> >> > >What was your fix? > > > (with apologies for the long delay) See the thread at http://lkml.org/lkml/2004/7/26/68. basically allow the userspace filesystem process to access behave like kswapd allocation-wise. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.