From nobody Wed Sep 10 02:33:50 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 2802FC001DF for ; Sun, 30 Jul 2023 15:16:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230075AbjG3PQs (ORCPT ); Sun, 30 Jul 2023 11:16:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230035AbjG3PQk (ORCPT ); Sun, 30 Jul 2023 11:16:40 -0400 Received: from mail-wm1-x32d.google.com (mail-wm1-x32d.google.com [IPv6:2a00:1450:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89A54171A for ; Sun, 30 Jul 2023 08:16:14 -0700 (PDT) Received: by mail-wm1-x32d.google.com with SMTP id 5b1f17b1804b1-3fe2048c910so2025485e9.1 for ; Sun, 30 Jul 2023 08:16:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1690730173; x=1691334973; 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=sRlgK3gsc81CRpAMRRPsywIlI5j9OUiW8IxZjNa20o0=; b=W/lVFu8oBYOHaQON2+IUAE4OeTID9l1Wz5BLxJdEu8LJBB9z/KErJPNGKn4gPKcqET TOz183J9eC9oj+adoUW1wOIA2x17GqKNs+kATE99/ZRY8Fjp8O5VirlHjPixUUm43ku4 z+wT3z1JbZFobFUIlYBs/gN3XFoPKT2xOzlfLL6MoMgEtn/SiRo+2YI4xg86K/JhVl3i MuhecVQM9cEuPwUzqT4PGXvn5nnp3Ror/whrcq0G86C37cVp/BcEGPKbi/b5/niap3Zq DtL+erRe6APzX6GQNORLFAEQj9gidto4zepL9icunXIYosg8Xv4r0ivr6Y0+U81B8I1M t8+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690730173; x=1691334973; 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=sRlgK3gsc81CRpAMRRPsywIlI5j9OUiW8IxZjNa20o0=; b=YZ3KGxN0H8XlPhQWdPsNzjiPZEJQntgotTMelPIicrugNOD/xy5FzjAwbMCMohbOnT MU4GhI+WjCvJJrn5Ig3sTLnoylcdGB6inONai6y+uHAYOOxXs9gjCfN/0lT5sMcZPbTm A0jnaOrm248kwuMPthVEK5DRwfWqKNS6WJdPtv1Lf5WiS5NdAzWlE0yZ3NFkEG1HeFnt ML7GRs19ORDhLmK22TSigItHLPiV/SmXGHLxl07AjieVhRxLomR7vB5kl1DG2DPpvi9G 7yqEPYcrnpOro+w5KmTWRju+1dQUmZdlt1z5UcEkYDzl+uwanupD3Wrn+Icg0IFqfC0G Ku3g== X-Gm-Message-State: ABy/qLbvk6sCB0Rof9wXWm+4Yk7oNos8J6amGuYvI1idkCPNB+n9xPbk RhPscleu2TXuHL1HeuT6NXZe35/+l3W6viI/nNw= X-Google-Smtp-Source: APBJJlFzVJI2UxHIjpRrxyZbsv8rAC3x9G9eCF0qIIb2iLIkSv48sgus3BhU4mIBADGNAt8oxdN7wQ== X-Received: by 2002:a05:600c:2809:b0:3fa:9767:c816 with SMTP id m9-20020a05600c280900b003fa9767c816mr5021376wmb.39.1690730173023; Sun, 30 Jul 2023 08:16:13 -0700 (PDT) Received: from localhost.localdomain ([2a02:6b6a:b465:0:eda5:aa63:ce24:dac2]) by smtp.gmail.com with ESMTPSA id f17-20020a7bcc11000000b003fd2d33ea53sm9123027wmh.14.2023.07.30.08.16.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 30 Jul 2023 08:16:12 -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: [v2 4/6] memblock: introduce MEMBLOCK_RSRV_NOINIT flag Date: Sun, 30 Jul 2023 16:16:04 +0100 Message-Id: <20230730151606.2871391-5-usama.arif@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230730151606.2871391-1-usama.arif@bytedance.com> References: <20230730151606.2871391-1-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 | 9 +++++++++ mm/memblock.c | 30 +++++++++++++++++++++++++----- 2 files changed, 34 insertions(+), 5 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index f71ff9f0ec81..de7760aeb870 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -40,6 +40,8 @@ extern unsigned long long max_possible_pfn; * via a driver, and never indicated in the firmware-provided memory map as * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the * kernel resource tree. + * @MEMBLOCK_RSRV_NOINIT: memory region for which struct pages are not ini= tialized + * (only for reserved regions). */ enum memblock_flags { MEMBLOCK_NONE =3D 0x0, /* No special request */ @@ -47,6 +49,7 @@ 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 initialize struct pages */ }; =20 /** @@ -125,6 +128,7 @@ 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_reserved_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 +263,11 @@ 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 43cb4404d94c..40690ce0b06e 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -991,6 +991,21 @@ int __init_memblock memblock_clear_nomap(phys_addr_t b= ase, phys_addr_t size) return memblock_setclr_flag(&memblock.memory, base, size, 0, MEMBLOCK_NOM= AP); } =20 +/** + * memblock_reserved_mark_noinit - Mark a reserved memory region with flag= MEMBLOCK_RSRV_NOINIT. + * @base: the base phys addr of the region + * @size: the size of the region + * + * struct pages will not be initialized for reserved memory regions marked= with + * %MEMBLOCK_RSRV_NOINIT. + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_reserved_mark_noinit(phys_addr_t base, phys_a= ddr_t size) +{ + return memblock_setclr_flag(&memblock.reserved, base, size, 1, MEMBLOCK_R= SRV_NOINIT); +} + static bool should_skip_region(struct memblock_type *type, struct memblock_region *m, int nid, int flags) @@ -2107,13 +2122,18 @@ 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; + if (!memblock_is_noinit(region)) { + nid =3D memblock_get_region_node(region); + start =3D region->base; + end =3D start + region->size; =20 - reserve_bootmem_region(start, end, nid); + reserve_bootmem_region(start, end, nid); + } } } =20 --=20 2.25.1