From patchwork Mon Mar 3 16:29:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13999167 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48FEF238D38 for ; Mon, 3 Mar 2025 16:30:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741019431; cv=none; b=QrC+Pv3sYsbom+uvCIjlYiB0VSvzEa2DS/x2kl4vNE69Tfm7kqT+jZM3UEhXC28XTrOLPV34i6NzohBkTIcwipczOaNaz323YPiOAHkaENDeHyg6Tci8U4F5AMVN5K7ZoJJN+aT/+GKTH8F35poNT9T4sJW0T5D29qo80qoSV0U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741019431; c=relaxed/simple; bh=ixANMC3lPCVB+QxhgoNOds44O6e5NynuKFD7IIp9IVE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JRBW7991CDnT2DK08a4/y3S85kZJzUFzQtGR/Hjbq50jD1iF/zWA8vKAZSCVXdZ7EiVvmcWWHFayeIMUuTWuQhdyql5A2ObmLGFK66rYTFY4ZMslx8gz8YSAx1tdmxNALOFjx0rZPeQw1FpnUfqbGEjoZArjOLjxIzbAEYa1j7Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Riz2rWRF; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Riz2rWRF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741019428; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XXsaZOoTqmrj90mJbBg0yoAKUyLdOWV9hsabR6NX2f0=; b=Riz2rWRFO3x5/chzOAssiXnAEfN9V+dv3CeWZ5SLSOdlzpbrzsf3MbYwe+yuEN8krCsUwh G+fxTiEBT/kC+KyOtkjCMjn9clsZ98euMgM4wrwatx7C2aEq2y6HrZWryxnOvoX4jS55dW hs6fk9SW7nlddUPBws7hBEUfulG4EqM= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-208-Kx_KW_38NQeZsITujuEJ-A-1; Mon, 03 Mar 2025 11:30:27 -0500 X-MC-Unique: Kx_KW_38NQeZsITujuEJ-A-1 X-Mimecast-MFC-AGG-ID: Kx_KW_38NQeZsITujuEJ-A_1741019426 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-43942e82719so33182255e9.2 for ; Mon, 03 Mar 2025 08:30:26 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741019426; x=1741624226; 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=XXsaZOoTqmrj90mJbBg0yoAKUyLdOWV9hsabR6NX2f0=; b=WUg5siMI2qkptL8seWCkiwHHoRM1JFMJ9tatmPok29wjUWTfse0YTuDIzr30zUqum+ kCRZu4vEOtL8e3KM6Ctb7MRhRpcFKib82xskGsIfGfwbmMgMEqETDkS803cjW5fWdD1z jXSs76oY77dX2gFGliTiSBYy6cKINagN21DyaC8Ssi9eYF4F+tXT2FzZOBXm7HKK0U6e 644iKR3veQUA/5YOfPLcj2SnCN/Ug20QIYyYJNfv5RhhodNBooIs1M0cL5jPD7Kx3mfF +AYCyeYsFKSftuJR5RpfdnuESkEsD4tS1U35rFhpFuRAAvn40KxLeTjt+T4qrdN08RSa d0Tg== X-Forwarded-Encrypted: i=1; AJvYcCVh3QkGjOIv9Jyb89FMUcA+XHOEFNKM6R6VcDJNXlzna6yD0SfZMizg5xVg1R6tgJjNa1Wh3sVTdypWhVRZ@vger.kernel.org X-Gm-Message-State: AOJu0Yy8hbkuCbuG2FcxIKUGFJ7p9JAcCs+21yapvMNgrnS7oTvsgFSC Me71uN3nAgxdEwJe6EgJp4XxWw6UP0BnQMDDNME+FQhSrKXXLRnzj1qIFeBeDAhYWaeGnw8Pek3 Ah9UrAda2GXJwkwy0ZhGSKpSc/wTs28g/keXJ+b0xl0UghGRi6AZYt/KT4QxErN4= X-Gm-Gg: ASbGncuKxHPNMYodWA8OWwWteLRRkAaJ3REmMHxtn5aQkKpIHt44P6spN4jElkE/I/x /zoLgG35y9ONY44TuI5kT/cN2t9D9YG/Laz+deHj6NhEI7j0g0I01gErh7zl13e5k0icN4DOAdB IHVMSqrAc1MbG3+4pDxRWEZdYzZK5PJwnzXtIoIS0q/H0+KPMvN8q5AXDSx2Yxn1duRzA2ytqFC AHwloCAsjMLPCPC87mBD+fK7A1KZevwzJHsZhqZuW3aFZsDiS/dDlFtHN/MHJP9Ylgl7NsuEMHD 46dpY4tzvgCTni4URJBwr0ulAFBvNqMW0XbAiY7wUvYG/m/k2X5OyaruKqvhtuyfKXTYHg2+4nD 2 X-Received: by 2002:a05:6000:1565:b0:391:9b2:f49a with SMTP id ffacd0b85a97d-39109b2f905mr4268651f8f.55.1741019425838; Mon, 03 Mar 2025 08:30:25 -0800 (PST) X-Google-Smtp-Source: AGHT+IHyH4J1EAqaHR0tUbY9OuS6FmG3s0lngE2eSOblLtE+C7Z78Ry//BFuo4023zOsYhDT+DJ8lw== X-Received: by 2002:a05:6000:1565:b0:391:9b2:f49a with SMTP id ffacd0b85a97d-39109b2f905mr4268630f8f.55.1741019425450; Mon, 03 Mar 2025 08:30:25 -0800 (PST) Received: from localhost (p200300cbc7349600af274326a2162bfb.dip0.t-ipconnect.de. [2003:cb:c734:9600:af27:4326:a216:2bfb]) by smtp.gmail.com with UTF8SMTPSA id ffacd0b85a97d-390e47a7b88sm14820945f8f.40.2025.03.03.08.30.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 03 Mar 2025 08:30:25 -0800 (PST) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, David Hildenbrand , Andrew Morton , "Matthew Wilcox (Oracle)" , Tejun Heo , Zefan Li , Johannes Weiner , =?utf-8?q?Michal_Koutn=C3=BD?= , Jonathan Corbet , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Muchun Song , "Liam R. Howlett" , Lorenzo Stoakes , Vlastimil Babka , Jann Horn Subject: [PATCH v3 04/20] mm: move hugetlb specific things in folio to page[3] Date: Mon, 3 Mar 2025 17:29:57 +0100 Message-ID: <20250303163014.1128035-5-david@redhat.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250303163014.1128035-1-david@redhat.com> References: <20250303163014.1128035-1-david@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Let's just move the hugetlb specific stuff to a separate page, and stop letting it overlay other fields for now. This frees up some space in page[2], which we will use on 32bit to free up some space in page[1]. While we could move these things to page[3] instead, it's cleaner to just move the hugetlb specific things out of the way and pack the core-folio stuff as tight as possible. ... and we can minimize the work required in dump_folio. We can now avoid re-initializing &folio->_deferred_list in hugetlb code. Hopefully dynamically allocating "strut folio" in the future will further clean this up. Signed-off-by: David Hildenbrand --- include/linux/mm_types.h | 27 +++++++++++++++++---------- mm/hugetlb.c | 1 - mm/page_alloc.c | 5 +++++ 3 files changed, 22 insertions(+), 11 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index e81be20bbabc6..1d9c68c551d42 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -405,20 +405,23 @@ struct folio { unsigned long _flags_2; unsigned long _head_2; /* public: */ - void *_hugetlb_subpool; - void *_hugetlb_cgroup; - void *_hugetlb_cgroup_rsvd; - void *_hugetlb_hwpoison; + struct list_head _deferred_list; /* private: the union with struct page is transitional */ }; + struct page __page_2; + }; + union { struct { - unsigned long _flags_2a; - unsigned long _head_2a; + unsigned long _flags_3; + unsigned long _head_3; /* public: */ - struct list_head _deferred_list; + void *_hugetlb_subpool; + void *_hugetlb_cgroup; + void *_hugetlb_cgroup_rsvd; + void *_hugetlb_hwpoison; /* private: the union with struct page is transitional */ }; - struct page __page_2; + struct page __page_3; }; }; @@ -455,8 +458,12 @@ FOLIO_MATCH(_refcount, _refcount_1); offsetof(struct page, pg) + 2 * sizeof(struct page)) FOLIO_MATCH(flags, _flags_2); FOLIO_MATCH(compound_head, _head_2); -FOLIO_MATCH(flags, _flags_2a); -FOLIO_MATCH(compound_head, _head_2a); +#undef FOLIO_MATCH +#define FOLIO_MATCH(pg, fl) \ + static_assert(offsetof(struct folio, fl) == \ + offsetof(struct page, pg) + 3 * sizeof(struct page)) +FOLIO_MATCH(flags, _flags_3); +FOLIO_MATCH(compound_head, _head_3); #undef FOLIO_MATCH /** diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 70a012af4a8d2..c15723c8d5e7f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1634,7 +1634,6 @@ static void __update_and_free_hugetlb_folio(struct hstate *h, folio_ref_unfreeze(folio, 1); - INIT_LIST_HEAD(&folio->_deferred_list); hugetlb_free_folio(folio); } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ae0f2a2e87369..2fc03cb13e49d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -975,6 +975,11 @@ static int free_tail_page_prepare(struct page *head_page, struct page *page) goto out; } break; + case 3: + /* the third tail page: hugetlb specifics overlap ->mappings */ + if (IS_ENABLED(CONFIG_HUGETLB_PAGE)) + break; + fallthrough; default: if (page->mapping != TAIL_MAPPING) { bad_page(page, "corrupted mapping in tail page");