From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH 1/4] kvm tools: Add ioeventfd support Date: Fri, 27 May 2011 13:57:19 +0300 Message-ID: <1306493839.3217.10.camel@lappy> References: <1306492621-10208-1-git-send-email-levinsasha928@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: penberg@kernel.org, john@jfloren.net, kvm@vger.kernel.org, mingo@elte.hu, asias.hejun@gmail.com, gorcunov@gmail.com, prasadjoshi124@gmail.com To: Stefan Hajnoczi Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:53746 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753Ab1E0K5i (ORCPT ); Fri, 27 May 2011 06:57:38 -0400 Received: by wya21 with SMTP id 21so1151585wya.19 for ; Fri, 27 May 2011 03:57:37 -0700 (PDT) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Fri, 2011-05-27 at 11:47 +0100, Stefan Hajnoczi wrote: > On Fri, May 27, 2011 at 11:36 AM, Sasha Levin wrote: > > ioeventfd is way provided by KVM to receive notifications about > > reads and writes to PIO and MMIO areas within the guest. > > > > Such notifications are usefull if all we need to know is that > > a specific area of the memory has been changed, and we don't need > > a heavyweight exit to happen. > > > > The implementation uses epoll to scale to large number of ioeventfds. > > > > Signed-off-by: Sasha Levin > > --- > > tools/kvm/Makefile | 1 + > > tools/kvm/include/kvm/ioeventfd.h | 27 ++++++++ > > tools/kvm/ioeventfd.c | 127 +++++++++++++++++++++++++++++++++++++ > > tools/kvm/kvm-run.c | 4 + > > 4 files changed, 159 insertions(+), 0 deletions(-) > > create mode 100644 tools/kvm/include/kvm/ioeventfd.h > > create mode 100644 tools/kvm/ioeventfd.c > > Did you run any benchmarks? > > Stefan Yes, they showed a nice improvements - I'll post them with a V2 of the patch. -- Sasha.