From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755229AbaIQL2D (ORCPT ); Wed, 17 Sep 2014 07:28:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30051 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754048AbaIQL2A (ORCPT ); Wed, 17 Sep 2014 07:28:00 -0400 Date: Wed, 17 Sep 2014 13:27:14 +0200 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: Gleb Natapov Cc: Andres Lagar-Cavilla , Gleb Natapov , Rik van Riel , Peter Zijlstra , Mel Gorman , Andy Lutomirski , Andrew Morton , Andrea Arcangeli , Sasha Levin , Jianyu Zhan , Paul Cassella , Hugh Dickins , Peter Feiner , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] kvm: Faults which trigger IO release the mmap_sem Message-ID: <20140917112713.GB1273@potion.brq.redhat.com> References: <1410811885-17267-1-git-send-email-andreslc@google.com> <20140917102635.GA30733@minantech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140917102635.GA30733@minantech.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2014-09-17 13:26+0300, Gleb Natapov: > For async_pf_execute() you do not need to even retry. Next guest's page fault > will retry it for you. Wouldn't that be a waste of vmentries? The guest might be able to handle interrupts while we are waiting, so if we used async-io-done notifier, this could work without CPU spinning. (Probably with added latency.)