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=-0.8 required=3.0 tests=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 55C9BC7618B for ; Tue, 23 Jul 2019 14:05:16 +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 2CE0F21738 for ; Tue, 23 Jul 2019 14:05:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CE0F21738 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]:42772 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpvPl-0007II-4e for qemu-devel@archiver.kernel.org; Tue, 23 Jul 2019 10:05:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43368) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpvPX-0006og-Ca for qemu-devel@nongnu.org; Tue, 23 Jul 2019 10:05:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hpvPW-0005Xf-EQ for qemu-devel@nongnu.org; Tue, 23 Jul 2019 10:04:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48962) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hpvPW-0005Wr-9H for qemu-devel@nongnu.org; Tue, 23 Jul 2019 10:04:58 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F1D5581DE0; Tue, 23 Jul 2019 14:04:56 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-116-45.ams2.redhat.com [10.36.116.45]) by smtp.corp.redhat.com (Postfix) with ESMTP id C39BB5B687; Tue, 23 Jul 2019 14:04:46 +0000 (UTC) From: Stefano Garzarella To: qemu-devel@nongnu.org Date: Tue, 23 Jul 2019 16:04:43 +0200 Message-Id: <20190723140445.12748-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 23 Jul 2019 14:04:57 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 0/2] pc: mmap kernel (ELF image) and initrd 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: Peter Maydell , Eduardo Habkost , Sergio Lopez , "Michael S. Tsirkin" , Julio Montes , "Dr . David Alan Gilbert" , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" In order to reduce the memory footprint when PVH kernel and initrd are used, we map them into memory instead of reading them. In this way we can share them between multiple instances of QEMU. v2: - Patch 1: used g_mapped_file_new_from_fd() with 'writeble' set to 'true'= , since we can modify the mapped buffer. [Paolo, Peter] These are the results using a PVH kernel and initrd (cpio): - memory footprint (using smem) [MB] QEMU before now # instances USS PSS USS PSS 1 102.0M 105.8M 102.3M 106.2M 2 94.6M 101.2M 72.3M 90.1M 4 94.1M 98.0M 72.0M 81.5M 8 94.0M 96.2M 71.8M 76.9M 16 93.9M 95.1M 71.6M 74.3M Initrd size: 3.0M Kernel image size: 28M sections size [size -A -d vmlinux]: 18.9M - boot time [ms] before now qemu_init_end: 63.85 55.91 linux_start_kernel: 82.11 (+18.26) 74.51 (+18.60) linux_start_user: 169.94 (+87.83) 159.06 (+84.56) QEMU command used: ./qemu-system-x86_64 -bios /path/to/seabios/out/bios.bin -no-hpet \ -machine q35,accel=3Dkvm,kernel_irqchip,nvdimm,sata=3Doff,smbus=3Doff= ,vmport=3Doff \ -cpu host -m 1G -smp 1 -vga none -display none -no-user-config -nodef= aults \ -kernel /path/to/vmlinux -initrd /path/to/rootfs.cpio \ -append 'root=3D/dev/mem0 ro console=3Dhvc0 pci=3Dlastbus=3D0 nosmap' Stefano Garzarella (2): elf-ops.h: Map into memory the ELF to load hw/i386/pc: Map into memory the initrd hw/i386/pc.c | 15 ++++++++--- include/hw/elf_ops.h | 64 ++++++++++++++++++++++++-------------------- 2 files changed, 46 insertions(+), 33 deletions(-) --=20 2.20.1