From patchwork Fri Dec 3 23:34:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 12656079 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id CB794C433F5 for ; Fri, 3 Dec 2021 23:43:55 +0000 (UTC) Received: from localhost ([::1]:42768 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mtIDa-0004p2-Ob for qemu-devel@archiver.kernel.org; Fri, 03 Dec 2021 18:43:54 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40858) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mtI4f-0006Bx-9W for qemu-devel@nongnu.org; Fri, 03 Dec 2021 18:34:41 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:40268) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mtI4c-0001or-7w for qemu-devel@nongnu.org; Fri, 03 Dec 2021 18:34:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638574477; 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=lIhV5K1u2wvXnKxE9a1/GDmXrykKf0FSebfksfskNA0=; b=i+ynqhFFrcGLRJXHnIH300HEiwDCTdX71cIffNi0JPs4xMa0rW93J/r+lvcsV9fNhARY7L siRKPWSfe2BxAQJPAZ7HqXaQRtSCtrCjaBsdjbeZ2hUETnlJcAO277+Ftkig/x7KvjWA+0 6OP1gXWYQNCCGmBLHDU+oHcn5gw0bAg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-169-Yg0FrP4mMhSQtBSjAXPesg-1; Fri, 03 Dec 2021 18:34:34 -0500 X-MC-Unique: Yg0FrP4mMhSQtBSjAXPesg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 317231030C20; Fri, 3 Dec 2021 23:34:33 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-43.bne.redhat.com [10.64.54.43]) by smtp.corp.redhat.com (Postfix) with ESMTP id D16BF60843; Fri, 3 Dec 2021 23:34:27 +0000 (UTC) From: Gavin Shan To: qemu-arm@nongnu.org Subject: [PATCH v3 1/2] virtio-mem: Correct default THP size for ARM64 Date: Sat, 4 Dec 2021 07:34:03 +0800 Message-Id: <20211203233404.37313-2-gshan@redhat.com> In-Reply-To: <20211203233404.37313-1-gshan@redhat.com> References: <20211203233404.37313-1-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=gshan@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.129.124; envelope-from=gshan@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.717, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, drjones@redhat.com, david@redhat.com, richard.henderson@linaro.org, qemu-devel@nongnu.org, eric.auger@redhat.com, shan.gavin@gmail.com, Jonathan.Cameron@huawei.com, imammedo@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The default block size is same as to the THP size, which is either retrieved from "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size" or hardcoded to 2MB. There are flaws in both mechanisms and this intends to fix them up. * When "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size" is used to getting the THP size, 32MB and 512MB are valid values when we have 16KB and 64KB page size on ARM64. * When the hardcoded THP size is used, 2MB, 32MB and 512MB are valid values when we have 4KB, 16KB and 64KB page sizes on ARM64. Co-developed-by: David Hildenbrand Signed-off-by: Gavin Shan Reviewed-by: Jonathan Cameron Reviewed-by: David Hildenbrand --- hw/virtio/virtio-mem.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index d5a578142b..b20595a496 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -38,14 +38,25 @@ */ #define VIRTIO_MEM_MIN_BLOCK_SIZE ((uint32_t)(1 * MiB)) -#if defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) || \ - defined(__powerpc64__) -#define VIRTIO_MEM_DEFAULT_THP_SIZE ((uint32_t)(2 * MiB)) -#else - /* fallback to 1 MiB (e.g., the THP size on s390x) */ -#define VIRTIO_MEM_DEFAULT_THP_SIZE VIRTIO_MEM_MIN_BLOCK_SIZE +static uint32_t virtio_mem_default_thp_size(void) +{ + uint32_t default_thp_size = VIRTIO_MEM_MIN_BLOCK_SIZE; + +#if defined(__x86_64__) || defined(__arm__) || defined(__powerpc64__) + default_thp_size = 2 * MiB; +#elif defined(__aarch64__) + if (qemu_real_host_page_size == 4 * KiB) { + default_thp_size = 2 * MiB; + } else if (qemu_real_host_page_size == 16 * KiB) { + default_thp_size = 32 * MiB; + } else if (qemu_real_host_page_size == 64 * KiB) { + default_thp_size = 512 * MiB; + } #endif + return default_thp_size; +} + /* * We want to have a reasonable default block size such that * 1. We avoid splitting THPs when unplugging memory, which degrades @@ -78,11 +89,8 @@ static uint32_t virtio_mem_thp_size(void) if (g_file_get_contents(HPAGE_PMD_SIZE_PATH, &content, NULL, NULL) && !qemu_strtou64(content, &endptr, 0, &tmp) && (!endptr || *endptr == '\n')) { - /* - * Sanity-check the value, if it's too big (e.g., aarch64 with 64k base - * pages) or weird, fallback to something smaller. - */ - if (!tmp || !is_power_of_2(tmp) || tmp > 16 * MiB) { + /* Sanity-check the value and fallback to something reasonable. */ + if (!tmp || !is_power_of_2(tmp)) { warn_report("Read unsupported THP size: %" PRIx64, tmp); } else { thp_size = tmp; @@ -90,7 +98,7 @@ static uint32_t virtio_mem_thp_size(void) } if (!thp_size) { - thp_size = VIRTIO_MEM_DEFAULT_THP_SIZE; + thp_size = virtio_mem_default_thp_size(); warn_report("Could not detect THP size, falling back to %" PRIx64 " MiB.", thp_size / MiB); }