From nobody Mon Feb 9 06:28:56 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 EDA3C2046AA for ; Wed, 8 Jan 2025 23:34:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736379248; cv=none; b=ig7kix7/hVnmTLWUijIHh3YTMDVaelkN44Wtaw0k0f1k948wNivuL+Alikw5+ToOZ6VssLu5+2hgiFQxSVwRzEL4U4oYMQQ4XHtY93HJnwJELEkfNhLH6uCvC5u3vmKUVG8Z52djlu+pviFoyUQarjfYTqfzpqjLtbeJZK/KJLE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736379248; c=relaxed/simple; bh=T+A7EDCCtFsA6mR2AJvLwkkIuPfFsPQ9QIiOqlu+nXc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F2OzdSqRrUfkBL2vI1fDxTdP3NhJs0obDAoJDfB+apBoIzTudfjSv4GhW2CgVLftE2bsxXKI4kdp91IzyKOS1Bdj7PiKfEhDv5SjI9rC5K30vrPyF14kTIGwdl/JL+fo/RyDHeRC1FRnEzYx6PtXG2j3419zhZ09g3Mg35NeU3Y= 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=bCZUQ6oK; arc=none smtp.client-ip=170.10.129.124 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="bCZUQ6oK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1736379245; 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=NlWBk/L/IkPkjBErBKE0II3MThdDUOorzPsxzF/l62g=; b=bCZUQ6oKniZdoiOuvPOBVVvqc/oVG4IZzSI1q87to5VtSBidywMswWtxJt6NmzTqdwmmgp q8SFtMa3XBU08YZCLekxBUgus4iOQWkBOYcB9TgxLnOFvswQQ/2QmokzoB25FmSQcaxNWi egru8owtlU4ts0RM8YSHZQtyaO1MNTE= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-529-f2Ks21HyPQGtWMlhN9XdfA-1; Wed, 08 Jan 2025 18:34:00 -0500 X-MC-Unique: f2Ks21HyPQGtWMlhN9XdfA-1 X-Mimecast-MFC-AGG-ID: f2Ks21HyPQGtWMlhN9XdfA Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BCE641956083; Wed, 8 Jan 2025 23:33:56 +0000 (UTC) Received: from h1.redhat.com (unknown [10.22.80.41]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 92A9019560AE; Wed, 8 Jan 2025 23:33:48 +0000 (UTC) From: Nico Pache To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: ryan.roberts@arm.com, anshuman.khandual@arm.com, catalin.marinas@arm.com, cl@gentwo.org, vbabka@suse.cz, mhocko@suse.com, apopple@nvidia.com, dave.hansen@linux.intel.com, will@kernel.org, baohua@kernel.org, jack@suse.cz, srivatsa@csail.mit.edu, haowenchao22@gmail.com, hughd@google.com, aneesh.kumar@kernel.org, yang@os.amperecomputing.com, peterx@redhat.com, ioworker0@gmail.com, wangkefeng.wang@huawei.com, ziy@nvidia.com, jglisse@google.com, surenb@google.com, vishal.moola@gmail.com, zokeefe@google.com, zhengqi.arch@bytedance.com, jhubbard@nvidia.com, 21cnbao@gmail.com, willy@infradead.org, kirill.shutemov@linux.intel.com, david@redhat.com, aarcange@redhat.com, raquini@redhat.com, dev.jain@arm.com, sunnanyong@huawei.com, usamaarif642@gmail.com, audra@redhat.com, akpm@linux-foundation.org Subject: [RFC 07/11] khugepaged: generalize __collapse_huge_page_* for mTHP support Date: Wed, 8 Jan 2025 16:31:23 -0700 Message-ID: <20250108233128.14484-8-npache@redhat.com> In-Reply-To: <20250108233128.14484-1-npache@redhat.com> References: <20250108233128.14484-1-npache@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Content-Type: text/plain; charset="utf-8" generalize the order of the __collapse_huge_page_* functions to support future mTHP collapse. No functional changes in this patch. Signed-off-by: Nico Pache --- mm/khugepaged.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 6daf3a943a1a..9eb161b04ee4 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -565,7 +565,8 @@ static int __collapse_huge_page_isolate(struct vm_area_= struct *vma, unsigned long address, pte_t *pte, struct collapse_control *cc, - struct list_head *compound_pagelist) + struct list_head *compound_pagelist, + u8 order) { struct page *page =3D NULL; struct folio *folio =3D NULL; @@ -573,7 +574,7 @@ static int __collapse_huge_page_isolate(struct vm_area_= struct *vma, int none_or_zero =3D 0, shared =3D 0, result =3D SCAN_FAIL, referenced = =3D 0; bool writable =3D false; =20 - for (_pte =3D pte; _pte < pte + HPAGE_PMD_NR; + for (_pte =3D pte; _pte < pte + (1 << order); _pte++, address +=3D PAGE_SIZE) { pte_t pteval =3D ptep_get(_pte); if (pte_none(pteval) || (pte_present(pteval) && @@ -711,14 +712,15 @@ static void __collapse_huge_page_copy_succeeded(pte_t= *pte, struct vm_area_struct *vma, unsigned long address, spinlock_t *ptl, - struct list_head *compound_pagelist) + struct list_head *compound_pagelist, + u8 order) { struct folio *src, *tmp; pte_t *_pte; pte_t pteval; =20 - for (_pte =3D pte; _pte < pte + HPAGE_PMD_NR; - _pte++, address +=3D PAGE_SIZE) { + for (_pte =3D pte; _pte < pte + (1 << order); + _pte++, address +=3D PAGE_SIZE) { pteval =3D ptep_get(_pte); if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) { add_mm_counter(vma->vm_mm, MM_ANONPAGES, 1); @@ -764,7 +766,8 @@ static void __collapse_huge_page_copy_failed(pte_t *pte, pmd_t *pmd, pmd_t orig_pmd, struct vm_area_struct *vma, - struct list_head *compound_pagelist) + struct list_head *compound_pagelist, + u8 order) { spinlock_t *pmd_ptl; =20 @@ -781,7 +784,7 @@ static void __collapse_huge_page_copy_failed(pte_t *pte, * Release both raw and compound pages isolated * in __collapse_huge_page_isolate. */ - release_pte_pages(pte, pte + HPAGE_PMD_NR, compound_pagelist); + release_pte_pages(pte, pte + (1 << order), compound_pagelist); } =20 /* @@ -802,7 +805,7 @@ static void __collapse_huge_page_copy_failed(pte_t *pte, static int __collapse_huge_page_copy(pte_t *pte, struct folio *folio, pmd_t *pmd, pmd_t orig_pmd, struct vm_area_struct *vma, unsigned long address, spinlock_t *ptl, - struct list_head *compound_pagelist) + struct list_head *compound_pagelist, u8 order) { unsigned int i; int result =3D SCAN_SUCCEED; @@ -810,7 +813,7 @@ static int __collapse_huge_page_copy(pte_t *pte, struct= folio *folio, /* * Copying pages' contents is subject to memory poison at any iteration. */ - for (i =3D 0; i < HPAGE_PMD_NR; i++) { + for (i =3D 0; i < (1 << order); i++) { pte_t pteval =3D ptep_get(pte + i); struct page *page =3D folio_page(folio, i); unsigned long src_addr =3D address + i * PAGE_SIZE; @@ -829,10 +832,10 @@ static int __collapse_huge_page_copy(pte_t *pte, stru= ct folio *folio, =20 if (likely(result =3D=3D SCAN_SUCCEED)) __collapse_huge_page_copy_succeeded(pte, vma, address, ptl, - compound_pagelist); + compound_pagelist, order); else __collapse_huge_page_copy_failed(pte, pmd, orig_pmd, vma, - compound_pagelist); + compound_pagelist, order); =20 return result; } @@ -996,11 +999,11 @@ static int check_pmd_still_valid(struct mm_struct *mm, static int __collapse_huge_page_swapin(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd, - int referenced) + int referenced, u8 order) { int swapped_in =3D 0; vm_fault_t ret =3D 0; - unsigned long address, end =3D haddr + (HPAGE_PMD_NR * PAGE_SIZE); + unsigned long address, end =3D haddr + ((1 << order) * PAGE_SIZE); int result; pte_t *pte =3D NULL; spinlock_t *ptl; @@ -1110,7 +1113,6 @@ static int collapse_huge_page(struct mm_struct *mm, u= nsigned long address, int result =3D SCAN_FAIL; struct vm_area_struct *vma; struct mmu_notifier_range range; - VM_BUG_ON(address & ~HPAGE_PMD_MASK); =20 /* @@ -1145,7 +1147,7 @@ static int collapse_huge_page(struct mm_struct *mm, u= nsigned long address, * that case. Continuing to collapse causes inconsistency. */ result =3D __collapse_huge_page_swapin(mm, vma, address, pmd, - referenced); + referenced, HPAGE_PMD_ORDER); if (result !=3D SCAN_SUCCEED) goto out_nolock; } @@ -1192,7 +1194,7 @@ static int collapse_huge_page(struct mm_struct *mm, u= nsigned long address, pte =3D pte_offset_map_lock(mm, &_pmd, address, &pte_ptl); if (pte) { result =3D __collapse_huge_page_isolate(vma, address, pte, cc, - &compound_pagelist); + &compound_pagelist, HPAGE_PMD_ORDER); spin_unlock(pte_ptl); } else { result =3D SCAN_PMD_NULL; @@ -1222,7 +1224,7 @@ static int collapse_huge_page(struct mm_struct *mm, u= nsigned long address, =20 result =3D __collapse_huge_page_copy(pte, folio, pmd, _pmd, vma, address, pte_ptl, - &compound_pagelist); + &compound_pagelist, HPAGE_PMD_ORDER); pte_unmap(pte); if (unlikely(result !=3D SCAN_SUCCEED)) goto out_up_write; --=20 2.47.1