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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 92027C41514 for ; Wed, 28 Aug 2019 08:46:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6958D23406 for ; Wed, 28 Aug 2019 08:46:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566981961; bh=SYNMMq01znmSNj5G0W+PjKmwx9zN78KMh0tsuO4IhcY=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=mD/PDPAYP/p7DwCMTRWTPHpPFMUtKoN2F2KsSPrYz41MlsEfi5L2lifDSvy5PorUg lOAQVYyKZYNqvhNHUZ6Jl6KsBG88c89bqUDth49QwvDQVBpX3GKTDupXlvbsaBkJ9s zyKXW0ArrcuHy6s2GNJKBFH8RDZ4HwpnjfLU34DA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726300AbfH1Ip4 convert rfc822-to-8bit (ORCPT ); Wed, 28 Aug 2019 04:45:56 -0400 Received: from mail-ot1-f65.google.com ([209.85.210.65]:35245 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726232AbfH1Ip4 (ORCPT ); Wed, 28 Aug 2019 04:45:56 -0400 Received: by mail-ot1-f65.google.com with SMTP id 100so2011748otn.2; Wed, 28 Aug 2019 01:45:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=jCxOMA9aKz6SC3UYzcS/O/Ome5CiEdeSa8P16zSjLyw=; b=mtVHIfLz2MYDqKv0z90pu/NAxxsgLVfBebaj1h8GhPpQgKlrIlsg8u8mUkghB++9fI oLpjzcJRRMJoVtnSGMP/RPDDBfgNOvBeFjshTz5xysC07a4jM+ar64+qL296DyRNRixz VZ/jstryf8mbnGy6rTiR95G4PylRZmca3c8dC9Mp8cqs3xg7Yf9gXSgX5j7xINpRPe0G rrmHviLz1RW/VgsOVOExvP/CZcdMgFChLEkLlxTSC1/uQ4giWB3cDCMfKAWPkGTHP8xa eyGP7GwdjfLiBYfTa/tRkcI/bSUj8wAGAxkjb9/6tBks6NzWM7Wf9NW2Qu+GHMz16yMa 1hhw== X-Gm-Message-State: APjAAAUeU1eWcnyuWHx4caEqL9izF/CcxyzK13zSVq2qdwv24nYzyRkN HoNKcGSDkK1TaZzZe8av1ufPhVukX0zYYIctdlI= X-Google-Smtp-Source: APXvYqwC2lZkwr9YxZ3bcwcAf22d6yK/9b2s9wjSflhVJcF8c3Hu86klsU+hStpBZP/K4omckicJLzQ8jSi7GQLdnp8= X-Received: by 2002:a05:6830:154:: with SMTP id j20mr2381058otp.266.1566981954882; Wed, 28 Aug 2019 01:45:54 -0700 (PDT) MIME-Version: 1.0 References: <1564643196-7797-1-git-send-email-wanpengli@tencent.com> <7b1e3025-f513-7068-32ac-4830d67b65ac@intel.com> <20190803202058.GA9316@amt.cnet> <20190826204045.GA24697@amt.cnet> In-Reply-To: From: "Rafael J. Wysocki" Date: Wed, 28 Aug 2019 10:45:44 +0200 Message-ID: Subject: Re: [PATCH] cpuidle-haltpoll: Enable kvm guest polling when dedicated physical CPUs are available To: Wanpeng Li Cc: Marcelo Tosatti , Paolo Bonzini , "Rafael J. Wysocki" , LKML , kvm , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Linux PM , "Michael S. Tsirkin" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Wed, Aug 28, 2019 at 10:34 AM Wanpeng Li wrote: > > On Tue, 27 Aug 2019 at 08:43, Wanpeng Li wrote: > > > > Cc Michael S. Tsirkin, > > On Tue, 27 Aug 2019 at 04:42, Marcelo Tosatti wrote: > > > > > > On Tue, Aug 13, 2019 at 08:55:29AM +0800, Wanpeng Li wrote: > > > > On Sun, 4 Aug 2019 at 04:21, Marcelo Tosatti wrote: > > > > > > > > > > On Thu, Aug 01, 2019 at 06:54:49PM +0200, Paolo Bonzini wrote: > > > > > > On 01/08/19 18:51, Rafael J. Wysocki wrote: > > > > > > > On 8/1/2019 9:06 AM, Wanpeng Li wrote: > > > > > > >> From: Wanpeng Li > > > > > > >> > > > > > > >> The downside of guest side polling is that polling is performed even > > > > > > >> with other runnable tasks in the host. However, even if poll in kvm > > > > > > >> can aware whether or not other runnable tasks in the same pCPU, it > > > > > > >> can still incur extra overhead in over-subscribe scenario. Now we can > > > > > > >> just enable guest polling when dedicated pCPUs are available. > > > > > > >> > > > > > > >> Cc: Rafael J. Wysocki > > > > > > >> Cc: Paolo Bonzini > > > > > > >> Cc: Radim Krčmář > > > > > > >> Cc: Marcelo Tosatti > > > > > > >> Signed-off-by: Wanpeng Li > > > > > > > > > > > > > > Paolo, Marcelo, any comments? > > > > > > > > > > > > Yes, it's a good idea. > > > > > > > > > > > > Acked-by: Paolo Bonzini > > Hi Marcelo, > > If you don't have more concern, I guess Rafael can apply this patch > now since the merge window is not too far. I will likely queue it up later today and it will go to linux-next early next week. Thanks!