From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 659E63A5E64 for ; Mon, 22 Jun 2026 10:19:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782123555; cv=none; b=laY3p3OlKw6eBVKDMKFKhnCzMAbOXZ16r2VLZ70KwF1XY+Ae7EkGKnnRCdErA7pIYp64bmzW2R4XMoM/e1LwYqNf9Towa2Rn32NSYDGETwRxk7At+lSxBFgzYr8WtX1SrD1JIYk1e9t1hbZ0Ta+e3q9J3qKfzw+AAYoLbvAZRfQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782123555; c=relaxed/simple; bh=3z9wKCPJYFiNqhRk0VWBEyzUrDoRqSiGTIjnAdQzCYU=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=c2AqWWrHN0VA7MJdKNa7VYxSsRGCDztV/O1yExrAuXMvJDo93WKqftuE6RxcdwWtUw+jMwfidiSMxFPkxIJtYKqeSkHDZwNL5RSN8YndxL8HkdgjTT7bHtNMDSBXUamVtjdV2UWDyONQ2HQETYTYagI9YlKpeGAU0trO2g7zCnw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mclapinski.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=UCVbARCG; arc=none smtp.client-ip=209.85.128.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--mclapinski.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="UCVbARCG" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-4924583c7baso26876495e9.1 for ; Mon, 22 Jun 2026 03:19:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782123552; x=1782728352; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=ZxNUIst3xSwB1DYnBacJeT4d2hOKW7KBo5q6WmN9Dto=; b=UCVbARCGuJ+4OP2YZ3nZWATNqWr6VwRsghB29BDUu2UbpiAQiKiGSvBZ9n4/e1+DaG 5b3eMudl2SoTid5HIeI0XThtRUbF8wyzODRinsGXOQpf7JXVcFSw+rrynS7qnrsQlWUd c3EPrB5zstn1UkTIvxSgwgn7zGXMmAMo/hZ8/2g2AeVEOSV5CLlFMZx+drVfxJNtLjVO krIm2lespRZqav74W1vvYshSgz1YDpIad2HQvH1Ly76r0tfFjmLXzA6G6pO2+yt7VGIA hpIq3dKSn7kzzwfD+tZuC3DdBvIbg8m6PW1pVHQIebCcGhY3KMi1Bo/ys3RRW2Xwc/Z0 3p9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782123552; x=1782728352; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=ZxNUIst3xSwB1DYnBacJeT4d2hOKW7KBo5q6WmN9Dto=; b=UPLvTZrIO4eDwQzDVMugGHqwPRuiY12tJKvEYoXhON/iYVHSXGblIZsTPDTp0+mp7R eI8cG9ezDbMbE9gQQYmALIf3l7X9kul/gnWcXwmpuPvXsRtK6GpiI48uYm59nJZuk7Vo LKBQTGlmkhYIX++5EGPU7KftIuTNlLzGGrqGDU/TB546UjtUao/c3w5mkaISlBkSXcqZ kAwfN9z2tY6hc+8Ti3FhcKWBUaLOFlIOqh0nkfwRRMyasqJ8bpy3XACGgO8Tai4s63wl 1AVBHewiYQRX6sI2rFFzAicKL1LyjJCZ586fWOXQDTi9PaF42n8ixjK2uE/hdcaHgnaA Hk6w== X-Gm-Message-State: AOJu0YxpF2C+SREjETUkacTWmFisa6iD7iye05ScNJA3hdfZ+8LCODSW lqTe+2+V0msYLe9Y6lBts+PUZjo2YQ3QoNQJxynoH/i0lQWVf96pQ8+c/TAtMnxNGwA25/Kw3NX xRJfbc6rQO+BUbVXX+bpxNA== X-Received: from wmpg40.prod.google.com ([2002:a05:600c:4ca8:b0:492:43ba:b63b]) (user=mclapinski job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:83cd:b0:492:43d2:9e6e with SMTP id 5b1f17b1804b1-49243d29f5amr187582275e9.9.1782123551512; Mon, 22 Jun 2026 03:19:11 -0700 (PDT) Date: Mon, 22 Jun 2026 12:19:01 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.55.0.rc0.799.gd6f94ed593-goog Message-ID: <20260622101901.223961-1-mclapinski@google.com> Subject: [PATCH] mm/hugetlb: init tails before init_migratetype From: Michal Clapinski To: Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , "Vlastimil Babka (SUSE)" , Kiryl Shutsemau , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Michal Clapinski Content-Type: text/plain; charset="UTF-8" Currently, if you enable HVO, DEFERRED_STRUCT_PAGE_INIT and VM_DEBUG the kernel will crash with the following stack trace get_pfnblock_bitmap_bitidx __set_pfnblock_flags_mask hugetlb_bootmem_init_migratetype prep_and_add_bootmem_folios gather_bootmem_prealloc_node gather_bootmem_prealloc_parallel padata_do_multithreaded gather_bootmem_prealloc hugetlb_init on this code VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); This code looks inside the struct page which will be uninitialized for hugetlb tail pages, which will cause a false positive. So let's initialize the tail pages before this happens. Fixes: 622026e87c40 ("mm/hugetlb: remove fake head pages") Signed-off-by: Michal Clapinski --- I think this one check is the only thing that fails, so I can probably just remove it instead. --- mm/hugetlb.c | 1 + mm/hugetlb_vmemmap.c | 14 +++++++++----- mm/hugetlb_vmemmap.h | 5 +++++ 3 files changed, 15 insertions(+), 5 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 571212b80835..de5e7c104c10 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4127,6 +4127,7 @@ static int __init hugetlb_init(void) } hugetlb_init_hstates(); + hugetlb_vmemmap_init_tails(); gather_bootmem_prealloc(); report_hugepages(); diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 133b46dfb09f..cf485c101926 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -867,14 +867,10 @@ static const struct ctl_table hugetlb_vmemmap_sysctls[] = { }, }; -static int __init hugetlb_vmemmap_init(void) +void __init hugetlb_vmemmap_init_tails(void) { - const struct hstate *h; struct zone *zone; - /* HUGETLB_VMEMMAP_RESERVE_SIZE should cover all used struct pages */ - BUILD_BUG_ON(__NR_USED_SUBPAGE > HUGETLB_VMEMMAP_RESERVE_PAGES); - for_each_zone(zone) { for (int i = 0; i < NR_VMEMMAP_TAILS; i++) { struct page *tail, *p; @@ -890,6 +886,14 @@ static int __init hugetlb_vmemmap_init(void) init_compound_tail(p + j, NULL, order, zone); } } +} + +static int __init hugetlb_vmemmap_init(void) +{ + const struct hstate *h; + + /* HUGETLB_VMEMMAP_RESERVE_SIZE should cover all used struct pages */ + BUILD_BUG_ON(__NR_USED_SUBPAGE > HUGETLB_VMEMMAP_RESERVE_PAGES); for_each_hstate(h) { if (hugetlb_vmemmap_optimizable(h)) { diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h index 18b490825215..91cdb28969fa 100644 --- a/mm/hugetlb_vmemmap.h +++ b/mm/hugetlb_vmemmap.h @@ -20,6 +20,7 @@ #define HUGETLB_VMEMMAP_RESERVE_PAGES (HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page)) #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +void hugetlb_vmemmap_init_tails(void); int hugetlb_vmemmap_restore_folio(const struct hstate *h, struct folio *folio); long hugetlb_vmemmap_restore_folios(const struct hstate *h, struct list_head *folio_list, @@ -72,6 +73,10 @@ static inline void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list { } +static inline void hugetlb_vmemmap_init_tails(void) +{ +} + static inline void hugetlb_vmemmap_optimize_bootmem_folios(struct hstate *h, struct list_head *folio_list) { -- 2.55.0.rc0.799.gd6f94ed593-goog