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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C9F84CA9ED0 for ; Fri, 1 Nov 2019 21:26:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A62E21855 for ; Fri, 1 Nov 2019 21:26:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VZtq4Z7E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727124AbfKAV0p (ORCPT ); Fri, 1 Nov 2019 17:26:45 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:50790 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727079AbfKAV0o (ORCPT ); Fri, 1 Nov 2019 17:26:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572643603; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vc9DkpMujQuhpCve3Y34f4TSvB+W8OlWdKhsXSlhGW0=; b=VZtq4Z7EDvydN/7C8E+ikm70ccdYigRNm7X8lfiqJ5EoJ9FIhyp5Qqah9+JTvN7e5dMwSB /y/3HrUDDJVTcRbB8gLMQHHoMhNebAfh7AoPb7GkHDy5YnkVFsXaEYPeNsaD0JqNMzI5Ts PfDkbKdMKHwRjlsd9Kc5z3LzV2wjK6M= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-273-GsvX0Ji3MkOSgzBUAc1JGg-1; Fri, 01 Nov 2019 17:26:42 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 021E2800D49; Fri, 1 Nov 2019 21:26:40 +0000 (UTC) Received: from amt.cnet (ovpn-112-2.gru2.redhat.com [10.97.112.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id CCE7F5D9E2; Fri, 1 Nov 2019 21:26:37 +0000 (UTC) Received: from amt.cnet (localhost [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id 9FBD910517E; Fri, 1 Nov 2019 19:26:19 -0200 (BRST) Received: (from marcelo@localhost) by amt.cnet (8.14.7/8.14.7/Submit) id xA1LQFgl020794; Fri, 1 Nov 2019 19:26:15 -0200 Date: Fri, 1 Nov 2019 19:26:15 -0200 From: Marcelo Tosatti To: Zhenzhong Duan Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, joao.m.martins@oracle.com, rafael.j.wysocki@intel.com, rkrcmar@redhat.com, pbonzini@redhat.com Subject: Re: [PATCH 5/5] cpuidle-haltpoll: fix up the branch check Message-ID: <20191101212613.GB20672@amt.cnet> References: <1572060239-17401-1-git-send-email-zhenzhong.duan@oracle.com> <1572060239-17401-6-git-send-email-zhenzhong.duan@oracle.com> MIME-Version: 1.0 In-Reply-To: <1572060239-17401-6-git-send-email-zhenzhong.duan@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: GsvX0Ji3MkOSgzBUAc1JGg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Sat, Oct 26, 2019 at 11:23:59AM +0800, Zhenzhong Duan wrote: > Ensure pool time is longer than block_ns, so there is a margin to > avoid vCPU get into block state unnecessorily. >=20 > Signed-off-by: Zhenzhong Duan > --- > drivers/cpuidle/governors/haltpoll.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/gover= nors/haltpoll.c > index 4b00d7a..59eadaf 100644 > --- a/drivers/cpuidle/governors/haltpoll.c > +++ b/drivers/cpuidle/governors/haltpoll.c > @@ -81,9 +81,9 @@ static void adjust_poll_limit(struct cpuidle_device *de= v, unsigned int block_us) > =09u64 block_ns =3D block_us*NSEC_PER_USEC; > =20 > =09/* Grow cpu_halt_poll_us if > -=09 * cpu_halt_poll_us < block_ns < guest_halt_poll_us > +=09 * cpu_halt_poll_us <=3D block_ns < guest_halt_poll_us > =09 */ > -=09if (block_ns > dev->poll_limit_ns && block_ns <=3D guest_halt_poll_ns= ) { > +=09if (block_ns >=3D dev->poll_limit_ns && block_ns < guest_halt_poll_ns= ) { =09=09=09=09=09 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ If block_ns =3D=3D guest_halt_poll_ns, you won't allow dev->poll_limit_ns t= o grow. Why is that? > @@ -101,7 +101,7 @@ static void adjust_poll_limit(struct cpuidle_device *= dev, unsigned int block_us) > =09=09=09val =3D guest_halt_poll_ns; > =20 > =09=09dev->poll_limit_ns =3D val; > -=09} else if (block_ns > guest_halt_poll_ns && > +=09} else if (block_ns >=3D guest_halt_poll_ns && > =09=09 guest_halt_poll_allow_shrink) { > =09=09unsigned int shrink =3D guest_halt_poll_shrink; And here you shrink if block_ns =3D=3D guest_halt_poll_ns. Not sure why that makes sense either.