From patchwork Thu Feb 10 22:48:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yury Norov X-Patchwork-Id: 12742559 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0204EC433FE for ; Thu, 10 Feb 2022 23:07:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345413AbiBJXHU (ORCPT ); Thu, 10 Feb 2022 18:07:20 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:57650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239716AbiBJXHS (ORCPT ); Thu, 10 Feb 2022 18:07:18 -0500 Received: from mail-qt1-x833.google.com (mail-qt1-x833.google.com [IPv6:2607:f8b0:4864:20::833]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5055655BB; Thu, 10 Feb 2022 15:07:19 -0800 (PST) Received: by mail-qt1-x833.google.com with SMTP id p14so7212026qtx.0; Thu, 10 Feb 2022 15:07:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=sS42IV/IyJJJQe1oR3KUsg/jNaiYCRP226dHL2TKSfc=; b=eocimBnfXPFWj8+E/eB1AYv5kSg66Mv6qkEhHGxwdqK6+dpi+peRet6nrjcRYlb1tJ HLjsHeS4HoimMpuxEg6Q1KFwlnDiLHRIUxX6DAS8BAJyYe1Wb5ZRuGjIJMKR1q4x1tax mR0v16h3AqcOHy0zSKKbFeKUUpHpXQKLT1K/LlXJmTYON2jCyhCt2CbAHCunDJet+SQf qB3xSxKlgbKAtVXuJt2VZ7Ky2ByxUPWa//VI9ZAvnNBy9epN/zB3cnDTCxQ9bKhG9BuX 3+3BcwaBmibYIEse7pP1iJqUGgPQy06oSK9nozPDLkXHxtbCOZzb3pzwlcco0UUiQ3qe mySw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=sS42IV/IyJJJQe1oR3KUsg/jNaiYCRP226dHL2TKSfc=; b=lk6t8MLwgU2dFFqPnJwRFF3vFOnCc7KeDA7EdJASpDozZmB0ue7q1Wr7QBzJ8fouGk aPfiYoFK/4UF9xm7blwfJIwCLyxVTAKkEPxkcuG50WHLkU3WqSyBSbNOyqCflQklxPas s6yFFJC22a/qVrh5yzNk+jDWP40XViZ+igg15GYl1Pbni3ZTUvS9N4qiAat1fF0Q1eE3 /B4k5Ryq00hCq9me7kLRkQAao2CrHDuUE/PiHBcLHnut8Feq4EG3ew61oKc2WwrMNH2A tNhFicd6ayz4vcuzxdzgpvCYlo+Jam0wn+vdMTmFDL6wZn35Nq9kZNRpodxK/jAUO91V 7ETg== X-Gm-Message-State: AOAM5316ViZc0B6pYJGF7tq3pfuH8cfqM0uaq/Fes6fe0lvi/i9aSzs3 jsQXEwjcpsDt49w9oGyzC9A= X-Google-Smtp-Source: ABdhPJzsKhjH0E928PMWg14kbD+gJ7XaexanfTXEjOjfj8p4ucvwelQVCnWVujQwOdKeD0pnOszvBg== X-Received: by 2002:ac8:7f82:: with SMTP id z2mr6441488qtj.591.1644534438427; Thu, 10 Feb 2022 15:07:18 -0800 (PST) Received: from localhost ([12.28.44.171]) by smtp.gmail.com with ESMTPSA id o13sm11924755qtv.36.2022.02.10.15.07.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Feb 2022 15:07:17 -0800 (PST) From: Yury Norov To: Yury Norov , Andy Shevchenko , Rasmus Villemoes , Andrew Morton , =?utf-8?b?TWljaGHFgiBNaXJvc8WC?= =?utf-8?b?YXc=?= , Greg Kroah-Hartman , Peter Zijlstra , David Laight , Joe Perches , Dennis Zhou , Emil Renner Berthing , Nicholas Piggin , Matti Vaittinen , Alexey Klimov , linux-kernel@vger.kernel.org, Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org Subject: [PATCH 07/49] KVM: x86: replace bitmap_weight with bitmap_empty where appropriate Date: Thu, 10 Feb 2022 14:48:51 -0800 Message-Id: <20220210224933.379149-8-yury.norov@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220210224933.379149-1-yury.norov@gmail.com> References: <20220210224933.379149-1-yury.norov@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In some places kvm/hyperv.c code calls bitmap_weight() to check if any bit of a given bitmap is set. It's better to use bitmap_empty() in that case because bitmap_empty() stops traversing the bitmap as soon as it finds first set bit, while bitmap_weight() counts all bits unconditionally. Signed-off-by: Yury Norov Reviewed-by: Vitaly Kuznetsov Reviewed-by: Sean Christopherson --- arch/x86/kvm/hyperv.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 6e38a7d22e97..06c2a5603123 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -90,7 +90,7 @@ static void synic_update_vector(struct kvm_vcpu_hv_synic *synic, { struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic); struct kvm_hv *hv = to_kvm_hv(vcpu->kvm); - int auto_eoi_old, auto_eoi_new; + bool auto_eoi_old, auto_eoi_new; if (vector < HV_SYNIC_FIRST_VALID_VECTOR) return; @@ -100,16 +100,16 @@ static void synic_update_vector(struct kvm_vcpu_hv_synic *synic, else __clear_bit(vector, synic->vec_bitmap); - auto_eoi_old = bitmap_weight(synic->auto_eoi_bitmap, 256); + auto_eoi_old = !bitmap_empty(synic->auto_eoi_bitmap, 256); if (synic_has_vector_auto_eoi(synic, vector)) __set_bit(vector, synic->auto_eoi_bitmap); else __clear_bit(vector, synic->auto_eoi_bitmap); - auto_eoi_new = bitmap_weight(synic->auto_eoi_bitmap, 256); + auto_eoi_new = !bitmap_empty(synic->auto_eoi_bitmap, 256); - if (!!auto_eoi_old == !!auto_eoi_new) + if (auto_eoi_old == auto_eoi_new) return; down_write(&vcpu->kvm->arch.apicv_update_lock);