From nobody Wed Sep 10 02:52:27 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6076FC001DC for ; Thu, 27 Jul 2023 20:47:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231933AbjG0UrO (ORCPT ); Thu, 27 Jul 2023 16:47:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232213AbjG0UrB (ORCPT ); Thu, 27 Jul 2023 16:47:01 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B87852D45 for ; Thu, 27 Jul 2023 13:46:36 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id 38308e7fff4ca-2b701e1ca63so21959931fa.1 for ; Thu, 27 Jul 2023 13:46:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1690490795; x=1691095595; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=JQe+LnlORYwelNDP2OagFjwF2/T/1IMvjhocyHCh0HM=; b=gVT8uA85Q/2RybadFL1WMGqwI8huoiPfSEh3Ga80yhJTkx2wqYddCczcvHucvrLvi3 8LyY62f1ojKZNCIJ1RJJ6AJm/H/D5kfULuGeQgjkEhp/sdQz5z18I7dL/szLmlIfJpYD u61EVQdgSt8wbKxI6DB5hsAcwBuLB2hgvn0jrCvRww9Z0lGEXVNLysQBc2Fe36p46uCT jl2OXbNIY2R4lV5NY2Ex7WgCxOm/ALG64TE59hb/8mRc6i3LDTDk1ah1xfi+hOTG8MYd 4LLgZYdnHkKk+A17Ls6+GXL7nzPHfRkZeRmwu0Uv3hqpWoCBuyANT80yrLWtGgfm1gge gtcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690490795; x=1691095595; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JQe+LnlORYwelNDP2OagFjwF2/T/1IMvjhocyHCh0HM=; b=fIwHg8/52HS2L+/h6TlO/UClI7myuMGNqms80m595MZbW/ka/rULtjlJm4N8KnXJ6m MhRGlKPptJGbH58GvKiXwHeggjCEFm95YAfcP9grwnmuc+c5qI6sYJgJhHqpa2cmRV0x l/5ZsxvA5tnDIuClAJOW54O1Ol2/Ry8ozTb+V5+J/SB+cJavogtQUv+vY0IQDCzcZZA/ 4+xfIMcAg7ABkXtU5i5bHG5psl5Ua+7d5syCXILErkGSPWnsPzfNDFIWPLJaWYQgsP1A KjdR1fr/KgwqdX6DnS0my2vIQDb6OFUCQ9hOhXxwFEXikMyPez0jcxDQZGqJ780RhOIB V28A== X-Gm-Message-State: ABy/qLZe596ymFhynY4Aqp2Gw3heu6nQkznfmI9tmOT7B04RD0ji9BKv d49NuY0uYgUsPPhUCy1XZ6V6fw== X-Google-Smtp-Source: APBJJlFfgB46RLeDSeeOkYepjrGae0ZQ1eLESbLa8jxhbH1/PX3Edir8uGhF64v2uGzIFXEGRina+Q== X-Received: by 2002:a2e:3003:0:b0:2b5:974f:385 with SMTP id w3-20020a2e3003000000b002b5974f0385mr129660ljw.9.1690490795035; Thu, 27 Jul 2023 13:46:35 -0700 (PDT) Received: from localhost.localdomain ([2a02:6b6a:b465:0:7e3e:db9e:70fa:9ccb]) by smtp.gmail.com with ESMTPSA id k1-20020a7bc401000000b003fc06169abdsm2701400wmi.2.2023.07.27.13.46.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Jul 2023 13:46:34 -0700 (PDT) From: Usama Arif To: linux-mm@kvack.org, muchun.song@linux.dev, mike.kravetz@oracle.com, rppt@kernel.org Cc: linux-kernel@vger.kernel.org, fam.zheng@bytedance.com, liangma@liangbit.com, simon.evans@bytedance.com, punit.agrawal@bytedance.com, Usama Arif Subject: [v1 4/6] memblock: introduce MEMBLOCK_RSRV_NOINIT flag Date: Thu, 27 Jul 2023 21:46:22 +0100 Message-Id: <20230727204624.1942372-5-usama.arif@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230727204624.1942372-1-usama.arif@bytedance.com> References: <20230727204624.1942372-1-usama.arif@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" For reserved memory regions marked with this flag, reserve_bootmem_region is not called during memmap_init_reserved_pages. This can be used to avoid struct page initialization for regions which won't need them, for e.g. hugepages with HVO enabled. Signed-off-by: Usama Arif --- include/linux/memblock.h | 7 +++++++ mm/memblock.c | 32 ++++++++++++++++++++++++++------ 2 files changed, 33 insertions(+), 6 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index f71ff9f0ec81..7f9d06c08592 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -47,6 +47,7 @@ enum memblock_flags { MEMBLOCK_MIRROR =3D 0x2, /* mirrored region */ MEMBLOCK_NOMAP =3D 0x4, /* don't add to kernel direct mapping */ MEMBLOCK_DRIVER_MANAGED =3D 0x8, /* always detected via a driver */ + MEMBLOCK_RSRV_NOINIT =3D 0x10, /* don't call reserve_bootmem_region for t= his region */ }; =20 /** @@ -125,6 +126,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_= t size); int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); +int memblock_rsrv_mark_noinit(phys_addr_t base, phys_addr_t size); =20 void memblock_free_all(void); void memblock_free(void *ptr, size_t size); @@ -259,6 +261,11 @@ static inline bool memblock_is_nomap(struct memblock_r= egion *m) return m->flags & MEMBLOCK_NOMAP; } =20 +static inline bool memblock_is_noinit(struct memblock_region *m) +{ + return m->flags & MEMBLOCK_RSRV_NOINIT; +} + static inline bool memblock_is_driver_managed(struct memblock_region *m) { return m->flags & MEMBLOCK_DRIVER_MANAGED; diff --git a/mm/memblock.c b/mm/memblock.c index 4fd431d16ef2..3a15708af3b6 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -997,6 +997,22 @@ int __init_memblock memblock_clear_nomap(phys_addr_t b= ase, phys_addr_t size) return memblock_setclr_flag(base, size, 0, MEMBLOCK_NOMAP, 0); } =20 +/** + * memblock_rsrv_mark_noinit - Mark a reserved memory region with flag MEM= BLOCK_RSRV_NOINIT. + * @base: the base phys addr of the region + * @size: the size of the region + * + * For memory regions marked with %MEMBLOCK_RSRV_NOINIT, reserve_bootmem_r= egion + * is not called during memmap_init_reserved_pages, hence struct pages are= not + * initialized for this region. + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_rsrv_mark_noinit(phys_addr_t base, phys_addr_= t size) +{ + return memblock_setclr_flag(base, size, 1, MEMBLOCK_RSRV_NOINIT, 1); +} + static bool should_skip_region(struct memblock_type *type, struct memblock_region *m, int nid, int flags) @@ -2113,13 +2129,17 @@ static void __init memmap_init_reserved_pages(void) memblock_set_node(start, end, &memblock.reserved, nid); } =20 - /* initialize struct pages for the reserved regions */ + /* + * initialize struct pages for reserved regions that don't have + * the MEMBLOCK_RSRV_NOINIT flag set + */ for_each_reserved_mem_region(region) { - nid =3D memblock_get_region_node(region); - start =3D region->base; - end =3D start + region->size; - - reserve_bootmem_region(start, end, nid); + if (!memblock_is_noinit(region)) { + nid =3D memblock_get_region_node(region); + start =3D region->base; + end =3D start + region->size; + reserve_bootmem_region(start, end, nid); + } } } =20 --=20 2.25.1