From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 951326B0062 for ; Mon, 2 Nov 2009 10:19:24 -0500 (EST) Message-ID: <4AEEF878.2090805@redhat.com> Date: Mon, 02 Nov 2009 17:19:20 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [PATCH 08/11] Add "wait for page" hypercall. References: <1257076590-29559-1-git-send-email-gleb@redhat.com> <1257076590-29559-9-git-send-email-gleb@redhat.com> <4AEED907.5030306@redhat.com> <20091102151320.GC27911@redhat.com> In-Reply-To: <20091102151320.GC27911@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Gleb Natapov Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On 11/02/2009 05:13 PM, Gleb Natapov wrote: > On Mon, Nov 02, 2009 at 03:05:11PM +0200, Avi Kivity wrote: > >> On 11/01/2009 01:56 PM, Gleb Natapov wrote: >> >>> We want to be able to inject async pagefault into guest event if a guest >>> is not executing userspace code. But in this case guest may receive >>> async page fault in non-sleepable context. In this case it will be >>> able to make "wait for page" hypercall vcpu will be put to sleep until >>> page is swapped in and guest can continue without reschedule. >>> >> What's wrong with just 'hlt' and checking in the guest? >> >> > Halting here will leave vcpu with interrupt disabled and this will prevent > "wake up" signal delivery. Page faults can be delivered with interrupts disabled. > Enabling interrupts is also not an options > since we can't be sure that vcpu can process interrupt at this point. > That's too bad, allowing interrupts in this context can help maintain responsiveness. -- error compiling committee.c: too many arguments to function -- 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