From nobody Mon Feb 9 00:54:33 2026 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 C53BDEB64D9 for ; Mon, 26 Jun 2023 17:15:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229928AbjFZRPw (ORCPT ); Mon, 26 Jun 2023 13:15:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231267AbjFZRO5 (ORCPT ); Mon, 26 Jun 2023 13:14:57 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9547010D2; Mon, 26 Jun 2023 10:14:50 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6A1EA1474; Mon, 26 Jun 2023 10:15:34 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 80DFE3F663; Mon, 26 Jun 2023 10:14:47 -0700 (PDT) From: Ryan Roberts To: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Yin Fengwei , David Hildenbrand , Yu Zhao , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-s390@vger.kernel.org Subject: [PATCH v1 03/10] mm: Introduce try_vma_alloc_movable_folio() Date: Mon, 26 Jun 2023 18:14:23 +0100 Message-Id: <20230626171430.3167004-4-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230626171430.3167004-1-ryan.roberts@arm.com> References: <20230626171430.3167004-1-ryan.roberts@arm.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" Opportunistically attempt to allocate high-order folios in highmem, optionally zeroed. Retry with lower orders all the way to order-0, until success. Although, of note, order-1 allocations are skipped since a large folio must be at least order-2 to work with the THP machinery. The user must check what they got with folio_order(). This will be used to oportunistically allocate large folios for anonymous memory with a sensible fallback under memory pressure. For attempts to allocate non-0 orders, we set __GFP_NORETRY to prevent high latency due to reclaim, instead preferring to just try for a lower order. The same approach is used by the readahead code when allocating large folios. Signed-off-by: Ryan Roberts --- mm/memory.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index 367bbbb29d91..53896d46e686 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3001,6 +3001,39 @@ static vm_fault_t fault_dirty_shared_page(struct vm_= fault *vmf) return 0; } =20 +static inline struct folio *vma_alloc_movable_folio(struct vm_area_struct = *vma, + unsigned long vaddr, int order, bool zeroed) +{ + gfp_t gfp =3D order > 0 ? __GFP_NORETRY | __GFP_NOWARN : 0; + + if (zeroed) + return vma_alloc_zeroed_movable_folio(vma, vaddr, gfp, order); + else + return vma_alloc_folio(GFP_HIGHUSER_MOVABLE | gfp, order, vma, + vaddr, false); +} + +/* + * Opportunistically attempt to allocate high-order folios, retrying with = lower + * orders all the way to order-0, until success. order-1 allocations are s= kipped + * since a folio must be at least order-2 to work with the THP machinery. = The + * user must check what they got with folio_order(). vaddr can be any virt= ual + * address that will be mapped by the allocated folio. + */ +static struct folio *try_vma_alloc_movable_folio(struct vm_area_struct *vm= a, + unsigned long vaddr, int order, bool zeroed) +{ + struct folio *folio; + + for (; order > 1; order--) { + folio =3D vma_alloc_movable_folio(vma, vaddr, order, zeroed); + if (folio) + return folio; + } + + return vma_alloc_movable_folio(vma, vaddr, 0, zeroed); +} + /* * Handle write page faults for pages that can be reused in the current vma * --=20 2.25.1