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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 3851DC2D0E5 for ; Wed, 25 Mar 2020 18:57:17 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F0A9D2074D for ; Wed, 25 Mar 2020 18:57:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NxqgAMS2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0A9D2074D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:41660 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHBDI-0000te-2X for qemu-devel@archiver.kernel.org; Wed, 25 Mar 2020 14:57:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49720) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHBCb-0000SV-PD for qemu-devel@nongnu.org; Wed, 25 Mar 2020 14:56:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jHBCa-0002SK-7V for qemu-devel@nongnu.org; Wed, 25 Mar 2020 14:56:33 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:52217) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jHBCa-0002Ri-3B for qemu-devel@nongnu.org; Wed, 25 Mar 2020 14:56:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585162591; 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=tecLq6ohQS0TdPNJbNbjK78jTPdhnW3ZoYuw7s4avTM=; b=NxqgAMS2ZDWEtTEWKJPTs5a7qUbYHTQu6cnnxVCGpka47GyBkv4vj0bJZANatVnH41qSoX 4Qgsh2E/4v7CQS6Qt9IMGKOAocm6tzBW4zHUzaddB/mcHIBfA4smsZlNDutq7qemEJd6tZ yKWyM2unvFks+vS35jmOhrLuRX5S03k= 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-11-c7UqmqQNN8qY0ah-uJu7jw-1; Wed, 25 Mar 2020 14:56:27 -0400 X-MC-Unique: c7UqmqQNN8qY0ah-uJu7jw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A28AF1005509; Wed, 25 Mar 2020 18:56:26 +0000 (UTC) Received: from localhost (unknown [10.40.208.76]) by smtp.corp.redhat.com (Postfix) with ESMTP id 82ABA16D22; Wed, 25 Mar 2020 18:56:15 +0000 (UTC) Date: Wed, 25 Mar 2020 19:56:14 +0100 From: Igor Mammedov To: Gerd Hoffmann Subject: Re: [PATCH 00/13] microvm: add acpi support Message-ID: <20200325195614.41ecb022@redhat.com> In-Reply-To: <20200325091636.rqqv3ewxue6wm5qe@sirius.home.kraxel.org> References: <20200319080117.7725-1-kraxel@redhat.com> <20200323065050-mutt-send-email-mst@kernel.org> <20200323120948.f6egd7rhfso6276p@sirius.home.kraxel.org> <20200323131658.30152128@redhat.com> <20200325091636.rqqv3ewxue6wm5qe@sirius.home.kraxel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 216.205.24.74 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , Sergio Lopez , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 25 Mar 2020 10:16:36 +0100 Gerd Hoffmann wrote: > > > mounted. Decided to use the "i8042: PNP: No PS/2 controller found." > > > line instead for a simple test (just check the kernel log timestamps, > > > three runs each). The ACPI initialization is already done at that > > > point, so it should be useful nevertheless. Here we go: > > > > > > Without acpi: > > > 0.277710 > > > 0.278852 > > > 0.279520 > > > > > > With acpi: > > > 0.283917 > > > 0.284262 > > > 0.284836 > > I wonder what would be difference with hw-reduced acpi > > The kernel does a bunch of reads+writes at boot (roughly 20-30), > mostly timer ports, so probably while initializing the pm_timer > clocksource. Then it stops talking to the acpi hardware, > preferring kvmclock clocksouce I guess. > > So I expect hw-reduced acpi wouldn't make much of a difference. > Actually trying that isn't that high on my priority list. > > There is bigger fish to fry, untangling the hw/i386/acpi-build.c > monster for starters, so building with ACPI=y + PCI=n works ... if you are after reducing start up time it may be better to leave alone acpi-build.c with a bunch of legacy/compat stuff and create microvm specific acpi file, and extract from acpi-build.c only common bits that are necessary to produce tables (i.e. do something similar hw/arm/virt-acpi-build.c) PS: side-note: guest kernel insist on finding PCI where it doesn't exists [ 0.301104] ACPI: bus type PCI registered [ 0.301717] acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 [ 0.302180] PCI: Fatal: No config space access function found it's probably the first time x86 generic kernel sees machine without PCI, and it probably could be fixed saving another 10-20ms > > cheers, > Gerd > >