From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH v2 2/4] KVM: Switch assigned device IRQ forwarding to threaded handler Date: Tue, 02 Nov 2010 18:58:56 +0100 Message-ID: <4CD05160.70602@siemens.com> References: <95377bcf3801240f0d79ff277bbe476df8ea98c7.1288712958.git.jan.kiszka@siemens.com> <20101102174440.GD1304@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Marcelo Tosatti , kvm , Alex Williamson To: "Michael S. Tsirkin" Return-path: Received: from thoth.sbs.de ([192.35.17.2]:22612 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751755Ab0KBR7P (ORCPT ); Tue, 2 Nov 2010 13:59:15 -0400 In-Reply-To: <20101102174440.GD1304@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Am 02.11.2010 18:44, Michael S. Tsirkin wrote: > On Tue, Nov 02, 2010 at 04:49:18PM +0100, Jan Kiszka wrote: >> This improves the IRQ forwarding for assigned devices: By using the >> kernel's threaded IRQ scheme, we can get rid of the latency-prone work >> queue and simplify the code in the same run. > > Interesting. Do you see any latency improvements from this? Haven't measured, but I was primarily thinking of real-time scenarios, ie. setups where you may want adjust the threaded IRQ priority - something you cannot do with the shared kevent thread. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux