From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A91A4C6778C for ; Tue, 3 Jul 2018 07:05:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6635624899 for ; Tue, 3 Jul 2018 07:05:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6635624899 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932212AbeGCHFJ (ORCPT ); Tue, 3 Jul 2018 03:05:09 -0400 Received: from terminus.zytor.com ([198.137.202.136]:50925 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754671AbeGCHFB (ORCPT ); Tue, 3 Jul 2018 03:05:01 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w6374rtL189888 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 3 Jul 2018 00:04:53 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w6374raj189885; Tue, 3 Jul 2018 00:04:53 -0700 Date: Tue, 3 Jul 2018 00:04:53 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Vitaly Kuznetsov Message-ID: Cc: tglx@linutronix.de, kys@microsoft.com, Tianyu.Lan@microsoft.com, hpa@zytor.com, haiyangz@microsoft.com, mingo@kernel.org, linux-kernel@vger.kernel.org, Michael.H.Kelley@microsoft.com, vkuznets@redhat.com, sthemmin@microsoft.com, mikelley@microsoft.com Reply-To: hpa@zytor.com, Tianyu.Lan@microsoft.com, kys@microsoft.com, tglx@linutronix.de, haiyangz@microsoft.com, Michael.H.Kelley@microsoft.com, linux-kernel@vger.kernel.org, mingo@kernel.org, vkuznets@redhat.com, sthemmin@microsoft.com, mikelley@microsoft.com In-Reply-To: <20180622170625.30688-4-vkuznets@redhat.com> References: <20180622170625.30688-4-vkuznets@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/hyperv] x86/hyper-v: Use cheaper HVCALL_SEND_IPI hypercall when possible Git-Commit-ID: 4bd06060762bc7e4834ecf9daeb78834f7a29582 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 4bd06060762bc7e4834ecf9daeb78834f7a29582 Gitweb: https://git.kernel.org/tip/4bd06060762bc7e4834ecf9daeb78834f7a29582 Author: Vitaly Kuznetsov AuthorDate: Fri, 22 Jun 2018 19:06:24 +0200 Committer: Thomas Gleixner CommitDate: Tue, 3 Jul 2018 09:00:34 +0200 x86/hyper-v: Use cheaper HVCALL_SEND_IPI hypercall when possible When there is no need to send an IPI to a CPU with VP number > 64 we can do the job with fast HVCALL_SEND_IPI hypercall. Signed-off-by: Vitaly Kuznetsov Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Cc: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: "H. Peter Anvin" Cc: Tianyu Lan Cc: "Michael Kelley (EOSG)" Link: https://lkml.kernel.org/r/20180622170625.30688-4-vkuznets@redhat.com --- arch/x86/hyperv/hv_apic.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c index 90055f89223b..ee962784d25b 100644 --- a/arch/x86/hyperv/hv_apic.c +++ b/arch/x86/hyperv/hv_apic.c @@ -99,6 +99,9 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector) int nr_bank = 0; int ret = 1; + if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) + return false; + local_irq_save(flags); arg = (struct ipi_arg_ex **)this_cpu_ptr(hyperv_pcpu_input_arg); @@ -140,8 +143,18 @@ static bool __send_ipi_mask(const struct cpumask *mask, int vector) if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR)) return false; - if ((ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) - return __send_ipi_mask_ex(mask, vector); + /* + * From the supplied CPU set we need to figure out if we can get away + * with cheaper HVCALL_SEND_IPI hypercall. This is possible when the + * highest VP number in the set is < 64. As VP numbers are usually in + * ascending order and match Linux CPU ids, here is an optimization: + * we check the VP number for the highest bit in the supplied set first + * so we can quickly find out if using HVCALL_SEND_IPI_EX hypercall is + * a must. We will also check all VP numbers when walking the supplied + * CPU set to remain correct in all cases. + */ + if (hv_cpu_number_to_vp_number(cpumask_last(mask)) >= 64) + goto do_ex_hypercall; ipi_arg.vector = vector; ipi_arg.cpu_mask = 0; @@ -153,16 +166,17 @@ static bool __send_ipi_mask(const struct cpumask *mask, int vector) * only target upto 64 CPUs. */ if (vcpu >= 64) - goto ipi_mask_done; + goto do_ex_hypercall; __set_bit(vcpu, (unsigned long *)&ipi_arg.cpu_mask); } ret = hv_do_fast_hypercall16(HVCALL_SEND_IPI, ipi_arg.vector, ipi_arg.cpu_mask); - -ipi_mask_done: return ((ret == 0) ? true : false); + +do_ex_hypercall: + return __send_ipi_mask_ex(mask, vector); } static bool __send_ipi_one(int cpu, int vector) @@ -218,10 +232,7 @@ static void hv_send_ipi_self(int vector) void __init hv_apic_init(void) { if (ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) { - if ((ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) - pr_info("Hyper-V: Using ext hypercalls for IPI\n"); - else - pr_info("Hyper-V: Using IPI hypercalls\n"); + pr_info("Hyper-V: Using IPI hypercalls\n"); /* * Set the IPI entry points. */