From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 4 Feb 2008 11:13:53 -0800 (PST) From: Christoph Lameter Subject: Re: [patch 1/3] mmu_notifier: Core code In-Reply-To: <20080203013323.GA7185@v2.random> Message-ID: References: <20080131045750.855008281@sgi.com> <20080131045812.553249048@sgi.com> <20080201035249.GE26420@sgi.com> <20080203013323.GA7185@v2.random> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Robin Holt , Avi Kivity , Izik Eidus , kvm-devel@lists.sourceforge.net, Peter Zijlstra , steiner@sgi.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, daniel.blueman@quadrics.com List-ID: On Sun, 3 Feb 2008, Andrea Arcangeli wrote: > On Thu, Jan 31, 2008 at 07:58:40PM -0800, Christoph Lameter wrote: > > Ok. Andrea wanted the same because then he can void the begin callouts. > > Exactly. I hope the page-pin will avoid me having to serialize the KVM > page fault against the start/end critical section. > > BTW, I wonder if the start/end critical section API is intended to > forbid scheduling inside it. In short I wonder if GRU can is allowed > to take a spinlock in _range_start as last thing before returning, and > to release that same spinlock in _range_end as first thing, and not to > be forced to use a mutex. _begin/end encloses code that may sleep and _begin/_end itself may sleep. So a semaphore may work but not a spinlock. -- 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