From nobody Wed Dec 17 05:17:39 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 BB0F4C3DA66 for ; Fri, 25 Aug 2023 11:19:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239827AbjHYLT1 (ORCPT ); Fri, 25 Aug 2023 07:19:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239381AbjHYLSz (ORCPT ); Fri, 25 Aug 2023 07:18:55 -0400 Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C9211FCB for ; Fri, 25 Aug 2023 04:18:52 -0700 (PDT) Received: by mail-wr1-x436.google.com with SMTP id ffacd0b85a97d-319559fd67dso685955f8f.3 for ; Fri, 25 Aug 2023 04:18:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1692962331; x=1693567131; 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=rt7VA+fn11wPN2WZOsDR2kSrdsBwWADUH8ZcQSjaiPs=; b=EsMNC1tzWSxQdc599l5SHDEEa98rqlp7iDryuFhBYk8fHJ511NFQyTznh0mCDBUIn8 VL8K3tloTbGtKUrcH4jjAAsVmaUTZ2RNBUAs8YhCr5NG+vVevNZdq3uQ1G1uBY6LhJVF rTwmWgEz1MvQA9fuhdFC9bXz4LoNfymZjqSABGUPV23JzQFZnk9thziUhDk9YadzQzpK 0Y4SguwVDubIC/esFXv70EfncJva9GyavT5l0kJrs+9ZjMhqgofSo0kMiSVl8P6uaV89 V29hVlv/XbysBximjie5EPo24O7osCBf+oDoT7rAPNGdseqXFPTWzYczRyNlM8M7odR8 9gkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692962331; x=1693567131; 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=rt7VA+fn11wPN2WZOsDR2kSrdsBwWADUH8ZcQSjaiPs=; b=M6flj4A8x/w8NgVcGLECzTLyw71Y4f3hkSW/cn6raUIJR2t0LPtA4cbFq8m1FQmT1q LG1A2AySW3pWnVwrr5YKpGOCIksJNda9/fi3uw9506OfmFm/8FPMMt5O3V8SQPZp9t5R EtRTIvpt6BAvSjo043/BWONnxI4KsDNr42tvvRTsYbZaQptY2acbcrHBW6kBqIIZ8hDS sCGOtGg4QlYygL3oLc8dSLlFUv9IJObeHfVdTqm3mFPRMsF17nL27FjUpDEO+8/+lQ61 iistUbhiaE3chIHzQqXIKElPScuMKkclSYVFhFpMy4PP7L9CAZbNYLxW3P6R30uTzp3G hWrw== X-Gm-Message-State: AOJu0Yyvzm1vLWO3qLiUjNVEZ45/e2risZgCElBFZHBd9CIwnqSe2YcP Do3llPiqASjUFT30m5mxydpezw== X-Google-Smtp-Source: AGHT+IEec5EPpcaKObbex9bUWyp4GWlAmHPClDlt9NrVYi+5iTZNS2Jj3ebXr6R8Gt7v2gUbQKOW1A== X-Received: by 2002:a5d:4403:0:b0:31a:d49a:38d with SMTP id z3-20020a5d4403000000b0031ad49a038dmr13545294wrq.54.1692962331003; Fri, 25 Aug 2023 04:18:51 -0700 (PDT) Received: from localhost.localdomain ([2a02:6b6a:b5c7:0:9000:8d13:d0bb:ba7d]) by smtp.gmail.com with ESMTPSA id g9-20020a056000118900b0031ad5fb5a0fsm1939502wrx.58.2023.08.25.04.18.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Aug 2023 04:18:50 -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, songmuchun@bytedance.com, fam.zheng@bytedance.com, liangma@liangbit.com, punit.agrawal@bytedance.com, Usama Arif Subject: [v3 3/4] memblock: introduce MEMBLOCK_RSRV_NOINIT_VMEMMAP flag Date: Fri, 25 Aug 2023 12:18:35 +0100 Message-Id: <20230825111836.1715308-4-usama.arif@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230825111836.1715308-1-usama.arif@bytedance.com> References: <20230825111836.1715308-1-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 Reviewed-by: Muchun Song --- include/linux/memblock.h | 10 ++++++++++ mm/memblock.c | 32 +++++++++++++++++++++++++++----- 2 files changed, 37 insertions(+), 5 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index f71ff9f0ec81..6d681d053880 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_VMEMMAP: memory region for which struct pages are + * not initialized (only for reserved regions). */ enum memblock_flags { MEMBLOCK_NONE =3D 0x0, /* No special request */ @@ -47,6 +49,8 @@ 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 */ + /* don't initialize struct pages associated with this reserver memory blo= ck */ + MEMBLOCK_RSRV_NOINIT_VMEMMAP =3D 0x10, }; =20 /** @@ -125,6 +129,7 @@ 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_vmemmap(phys_addr_t base, phys_addr_t si= ze); =20 void memblock_free_all(void); void memblock_free(void *ptr, size_t size); @@ -259,6 +264,11 @@ static inline bool memblock_is_nomap(struct memblock_r= egion *m) return m->flags & MEMBLOCK_NOMAP; } =20 +static inline bool memblock_is_noinit_vmemmap(struct memblock_region *m) +{ + return m->flags & MEMBLOCK_RSRV_NOINIT_VMEMMAP; +} + 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..a9782228c840 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -991,6 +991,23 @@ 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_vmemmap - Mark a reserved memory region w= ith flag + * MEMBLOCK_RSRV_NOINIT_VMEMMAP. + * @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_VMEMMAP. + * + * Return: 0 on success, -errno on failure. + */ +int __init_memblock memblock_reserved_mark_noinit_vmemmap(phys_addr_t base= , phys_addr_t size) +{ + return memblock_setclr_flag(&memblock.reserved, base, size, 1, + MEMBLOCK_RSRV_NOINIT_VMEMMAP); +} + static bool should_skip_region(struct memblock_type *type, struct memblock_region *m, int nid, int flags) @@ -2107,13 +2124,18 @@ 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_VMEMMAP 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_vmemmap(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