From patchwork Tue Jul 23 09:07:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 11054141 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DDE0B912 for ; Tue, 23 Jul 2019 09:07:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CA9602859F for ; Tue, 23 Jul 2019 09:07:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BF405285D4; Tue, 23 Jul 2019 09:07:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 749E92859F for ; Tue, 23 Jul 2019 09:07:54 +0000 (UTC) Received: from localhost ([::1]:40450 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpqm1-0004Vg-10 for patchwork-qemu-devel@patchwork.kernel.org; Tue, 23 Jul 2019 05:07:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41510) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpqlh-0003Bh-2N for qemu-devel@nongnu.org; Tue, 23 Jul 2019 05:07:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hpqld-00020w-9R for qemu-devel@nongnu.org; Tue, 23 Jul 2019 05:07:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59512) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hpqlb-0001zZ-Ut for qemu-devel@nongnu.org; Tue, 23 Jul 2019 05:07:29 -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 mx1.redhat.com (Postfix) with ESMTPS id 77BCF3082B4B; Tue, 23 Jul 2019 09:07:26 +0000 (UTC) Received: from steredhat.redhat.com (unknown [10.36.118.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id F29165D9CC; Tue, 23 Jul 2019 09:07:19 +0000 (UTC) From: Stefano Garzarella To: qemu-devel@nongnu.org Date: Tue, 23 Jul 2019 11:07:16 +0200 Message-Id: <20190723090718.14590-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Tue, 23 Jul 2019 09:07:26 +0000 (UTC) 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 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: Eduardo Habkost , Sergio Lopez , "Michael S. Tsirkin" , Julio Montes , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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. 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=kvm,kernel_irqchip,nvdimm,sata=off,smbus=off,vmport=off \ -cpu host -m 1G -smp 1 -vga none -display none -no-user-config -nodefaults \ -kernel /path/to/vmlinux -initrd /path/to/rootfs.cpio \ -append 'root=/dev/mem0 ro console=hvc0 pci=lastbus=0 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 | 59 ++++++++++++++++++++++---------------------- 2 files changed, 41 insertions(+), 33 deletions(-)