{"id":2219956,"url":"http://patchwork.ozlabs.org/api/1.2/patches/2219956/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260405125240.2558577-32-songmuchun@bytedance.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/1.2/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<20260405125240.2558577-32-songmuchun@bytedance.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/20260405125240.2558577-32-songmuchun@bytedance.com/","date":"2026-04-05T12:52:22","name":"[31/49] mm/hugetlb: remove HUGE_BOOTMEM_HVO flag and simplify pre-HVO logic","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"4d696eac199fde6ad55cd2de3c36600ebc8d53b6","submitter":{"id":78930,"url":"http://patchwork.ozlabs.org/api/1.2/people/78930/?format=json","name":"Muchun Song","email":"songmuchun@bytedance.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260405125240.2558577-32-songmuchun@bytedance.com/mbox/","series":[{"id":498783,"url":"http://patchwork.ozlabs.org/api/1.2/series/498783/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=498783","date":"2026-04-05T12:51:51","name":"mm: Generalize vmemmap optimization for DAX and HugeTLB","version":1,"mbox":"http://patchwork.ozlabs.org/series/498783/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2219956/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2219956/checks/","tags":{},"related":[],"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=bytedance.com header.i=@bytedance.com\n header.a=rsa-sha256 header.s=google header.b=j5YbNmt4;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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Howlett\" ,\n\tVlastimil Babka ,\n\tMike Rapoport ,\n\tSuren Baghdasaryan ,\n\tMichal Hocko ,\n\tNicholas Piggin ,\n\tChristophe Leroy ,\n\taneesh.kumar@linux.ibm.com,\n\tjoao.m.martins@oracle.com,\n\tlinux-mm@kvack.org,\n\tlinuxppc-dev@lists.ozlabs.org,\n\tlinux-kernel@vger.kernel.org,\n\tMuchun Song ","Subject":"[PATCH 31/49] mm/hugetlb: remove HUGE_BOOTMEM_HVO flag and simplify\n pre-HVO logic","Date":"Sun, 5 Apr 2026 20:52:22 +0800","Message-Id":"<20260405125240.2558577-32-songmuchun@bytedance.com>","X-Mailer":"git-send-email 2.20.1","In-Reply-To":"<20260405125240.2558577-1-songmuchun@bytedance.com>","References":"<20260405125240.2558577-1-songmuchun@bytedance.com>","X-Mailing-List":"linuxppc-dev@lists.ozlabs.org","List-Id":"","List-Help":"","List-Owner":"","List-Post":"","List-Archive":",\n ","List-Subscribe":",\n ,\n ","List-Unsubscribe":"","Precedence":"list","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","X-Spam-Status":"No, score=-0.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID,\n\tDKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS\n\tautolearn=disabled version=4.0.1 OzLabs 8","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org"},"content":"The pre-HVO feature is used to optimize the vmemmap pages of HugeTLB\nbootmem pages. Previously, the HUGE_BOOTMEM_HVO flag was used to\nindicate whether a bootmem page has been pre-optimized.\n\nHowever, we can directly determine if a huge page is pre-optimized by\nchecking its section's optimization status using\nsection_vmemmap_optimizable(). The pre-initialization mechanism of\nvmemmap has been completely removed in previous patches, making the\nHUGE_BOOTMEM_HVO flag and its related checks redundant.\n\nBy directly using section_vmemmap_optimizable(), we can safely remove\nthe HUGE_BOOTMEM_HVO flag, clean up the associated state maintenance in\nstruct huge_bootmem_page, and simplify the bootmem page optimization\nchecks in the hugetlb initialization path.\n\nSigned-off-by: Muchun Song \n---\n include/linux/hugetlb.h | 5 ++---\n mm/hugetlb.c | 16 ++--------------\n mm/hugetlb_vmemmap.c | 5 -----\n 3 files changed, 4 insertions(+), 22 deletions(-)","diff":"diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h\nindex 23d95ed6121f..6bedeaee9b79 100644\n--- a/include/linux/hugetlb.h\n+++ b/include/linux/hugetlb.h\n@@ -695,9 +695,8 @@ struct huge_bootmem_page {\n \tstruct cma *cma;\n };\n \n-#define HUGE_BOOTMEM_HVO\t\t0x0001\n-#define HUGE_BOOTMEM_ZONES_VALID\t0x0002\n-#define HUGE_BOOTMEM_CMA\t\t0x0004\n+#define HUGE_BOOTMEM_ZONES_VALID\tBIT(0)\n+#define HUGE_BOOTMEM_CMA\t\tBIT(1)\n \n int isolate_or_dissolve_huge_folio(struct folio *folio, struct list_head *list);\n int replace_free_hugepage_folios(unsigned long start_pfn, unsigned long end_pfn);\ndiff --git a/mm/hugetlb.c b/mm/hugetlb.c\nindex dff94ab7040a..59728e942384 100644\n--- a/mm/hugetlb.c\n+++ b/mm/hugetlb.c\n@@ -3193,11 +3193,6 @@ static void __init hugetlb_folio_init_vmemmap(struct folio *folio,\n \tprep_compound_head(&folio->page, huge_page_order(h));\n }\n \n-static bool __init hugetlb_bootmem_page_prehvo(struct huge_bootmem_page *m)\n-{\n-\treturn m->flags & HUGE_BOOTMEM_HVO;\n-}\n-\n /*\n * memblock-allocated pageblocks might not have the migrate type set\n * if marked with the 'noinit' flag. Set it to the default (MIGRATE_MOVABLE)\n@@ -3284,16 +3279,9 @@ static void __init gather_bootmem_prealloc_node(unsigned long nid)\n \t\t\t\t\t OPTIMIZED_FOLIO_VMEMMAP_PAGE_STRUCTS);\n \t\tinit_new_hugetlb_folio(folio);\n \n-\t\tif (hugetlb_bootmem_page_prehvo(m)) {\n-\t\t\t/*\n-\t\t\t * If pre-HVO was done, just set the\n-\t\t\t * flag, the HVO code will then skip\n-\t\t\t * this folio.\n-\t\t\t */\n+\t\tif (section_vmemmap_optimizable(__pfn_to_section(folio_pfn(folio))))\n \t\t\tfolio_set_hugetlb_vmemmap_optimized(folio);\n-\t\t\tsection_set_order_pfn_range(folio_pfn(folio),\n-\t\t\t\t\t\t pages_per_huge_page(h), 0);\n-\t\t}\n+\t\tsection_set_order_pfn_range(folio_pfn(folio), folio_nr_pages(folio), 0);\n \n \t\tif (hugetlb_bootmem_page_earlycma(m))\n \t\t\tfolio_set_hugetlb_cma(folio);\ndiff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c\nindex 8c567b8c67cc..a190b9b94346 100644\n--- a/mm/hugetlb_vmemmap.c\n+++ b/mm/hugetlb_vmemmap.c\n@@ -711,12 +711,7 @@ void __init hugetlb_vmemmap_optimize_bootmem_page(struct huge_bootmem_page *m)\n \tif (!READ_ONCE(vmemmap_optimize_enabled))\n \t\treturn;\n \n-\tif (!hugetlb_vmemmap_optimizable(h))\n-\t\treturn;\n-\n \tsection_set_order_pfn_range(pfn, pages_per_huge_page(h), huge_page_order(h));\n-\tif (section_vmemmap_optimizable(__pfn_to_section(pfn)))\n-\t\tm->flags |= HUGE_BOOTMEM_HVO;\n }\n \n static const struct ctl_table hugetlb_vmemmap_sysctls[] = {\n","prefixes":["31/49"]}