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 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 8853EC43144 for ; Fri, 22 Jun 2018 17:06:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E21E2466C for ; Fri, 22 Jun 2018 17:06:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4E21E2466C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S933067AbeFVRGi (ORCPT ); Fri, 22 Jun 2018 13:06:38 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35442 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754633AbeFVRGf (ORCPT ); Fri, 22 Jun 2018 13:06:35 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 62992406E8C4; Fri, 22 Jun 2018 17:06:34 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.43.2.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id A68561C59F; Fri, 22 Jun 2018 17:06:32 +0000 (UTC) From: Vitaly Kuznetsov To: x86@kernel.org Cc: devel@linuxdriverproject.org, linux-kernel@vger.kernel.org, "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Tianyu Lan , "Michael Kelley (EOSG)" Subject: [PATCH 3/4] x86/hyper-v: use cheaper HVCALL_SEND_IPI hypercall when possible Date: Fri, 22 Jun 2018 19:06:24 +0200 Message-Id: <20180622170625.30688-4-vkuznets@redhat.com> In-Reply-To: <20180622170625.30688-1-vkuznets@redhat.com> References: <20180622170625.30688-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 22 Jun 2018 17:06:34 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 22 Jun 2018 17:06:34 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'vkuznets@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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. */ -- 2.14.4