Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754014AbbGBQWE (ORCPT ); Thu, 2 Jul 2015 12:22:04 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:23950 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753051AbbGBQVp (ORCPT ); Thu, 2 Jul 2015 12:21:45 -0400 X-IronPort-AV: E=Sophos;i="5.15,394,1432598400"; d="scan'208";a="280771425" Message-ID: <55956515.5050103@citrix.com> Date: Thu, 2 Jul 2015 17:21:41 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: Boris Ostrovsky , , CC: , , , , Subject: Re: [Xen-devel] [PATCH v5 3/6] xen/PMU: Initialization code for Xen PMU References: <1435848816-3323-1-git-send-email-boris.ostrovsky@oracle.com> <1435848816-3323-4-git-send-email-boris.ostrovsky@oracle.com> In-Reply-To: <1435848816-3323-4-git-send-email-boris.ostrovsky@oracle.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1295 Lines: 34 On 02/07/15 15:53, Boris Ostrovsky wrote: > Map shared data structure that will hold CPU registers, VPMU context, > V/PCPU IDs of the CPU interrupted by PMU interrupt. Hypervisor fills > this information in its handler and passes it to the guest for further > processing. > > Set up PMU VIRQ. > > Now that perf infrastructure will assume that PMU is available on a PV > guest we need to be careful and make sure that accesses via RDPMC > instruction don't cause fatal traps by the hypervisor. Provide a nop > RDPMC handler. > > For the same reason avoid issuing a warning on a write to APIC's LVTPC. > > Both of these will be made functional in later patches. [...] > + rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu, > + xen_pmu_irq_handler, > + IRQF_PERCPU|IRQF_NOBALANCING, > + pmu_name, NULL); If you bind a VIRQ as IRQF_PERCPU it can only be safely unbound on the CPU it is bound to (because the percpu handler does not take the desc->lock). Otherwise, Reviewed-by: David Vrabel David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/