From nobody Mon Feb 9 20:30:24 2026 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 6A51FC77B7A for ; Mon, 12 Jun 2023 03:08:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234321AbjFLDI1 (ORCPT ); Sun, 11 Jun 2023 23:08:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233094AbjFLDIR (ORCPT ); Sun, 11 Jun 2023 23:08:17 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70AB4E5F; Sun, 11 Jun 2023 20:08:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=kYsaDINwgGyBkCQoDFNAkvO4v5df2UfOXAdRONE+VsA=; b=cuhGQNGphwJUwp0UMhVoYyu2tM H9F7lOZDO201p3qw3R1q8bQtHyuWu0Ww+eKkYHBp2SnCKuOjfD6kgi6m69yXk4p8uoAisA9qsHuMv NZ+EO4hMOMVyYXlSs63l3oG5dPiJ78trxjJexR5Sfy8VX8lTb2HSP6n5JCMPs1BrMk2t353Ht4z7y ajHHQh6qV3BcUH7Np9z/Hyh/VfcsEyJLb2dEfJQ7sbKUTpS2sgvFs+l5wj+LyR9ojtmX1GZtq1CuV 93PdN6DAikYuO8xL+WRqN403rR53yreatar8GTfojD5i+4Meicwk0sy7/jFlbJgYm2fwuoD1f6VgC oUxdexdQ==; Received: from [2601:1c2:980:9ec0::2764] (helo=bombadil.infradead.org) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1q8Xuf-002P78-1j; Mon, 12 Jun 2023 03:08:13 +0000 From: Randy Dunlap To: linux-kernel@vger.kernel.org Cc: Randy Dunlap , Suraj Jitindar Singh , Paolo Bonzini , Sean Christopherson , kvm@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org Subject: [PATCH 1/4] Documentation: KVM: make corrections to halt-polling.rst Date: Sun, 11 Jun 2023 20:08:07 -0700 Message-ID: <20230612030810.23376-2-rdunlap@infradead.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230612030810.23376-1-rdunlap@infradead.org> References: <20230612030810.23376-1-rdunlap@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Module parameters are in sysfs, not debugfs, so change that. Remove superfluous "that" following "Note:". Hyphenate "system-wide" values. Hyphenate "trade-off". Don't treat "denial of service" as a verb. Signed-off-by: Randy Dunlap Cc: Suraj Jitindar Singh Cc: Paolo Bonzini Cc: Sean Christopherson Cc: kvm@vger.kernel.org Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org --- Documentation/virt/kvm/halt-polling.rst | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff -- a/Documentation/virt/kvm/halt-polling.rst b/Documentation/virt/kvm/= halt-polling.rst --- a/Documentation/virt/kvm/halt-polling.rst +++ b/Documentation/virt/kvm/halt-polling.rst @@ -112,11 +112,11 @@ powerpc kvm-hv case. | | function. | | +-----------------------+---------------------------+---------------------= ----+ =20 -These module parameters can be set from the debugfs files in: +These module parameters can be set from the sysfs files in: =20 /sys/module/kvm/parameters/ =20 -Note: that these module parameters are system wide values and are not able= to +Note: these module parameters are system-wide values and are not able to be tuned on a per vm basis. =20 Any changes to these parameters will be picked up by new and existing vCPU= s the @@ -142,12 +142,12 @@ Further Notes global max polling interval (halt_poll_ns) then the host will always pol= l for the entire block time and thus cpu utilisation will go to 100%. =20 -- Halt polling essentially presents a trade off between power usage and la= tency and +- Halt polling essentially presents a trade-off between power usage and la= tency and the module parameters should be used to tune the affinity for this. Idle= cpu time is essentially converted to host kernel time with the aim of decreasing lat= ency when entering the guest. =20 - Halt polling will only be conducted by the host when no other tasks are = runnable on that cpu, otherwise the polling will cease immediately and schedule will= be invoked to - allow that other task to run. Thus this doesn't allow a guest to denial = of service the - cpu. + allow that other task to run. Thus this doesn't allow a guest to cause d= enial of service + of the cpu.