From nobody Wed Sep 10 02:51:18 2025 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 1215BEB64DD for ; Thu, 27 Jul 2023 20:47:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232388AbjG0UrF (ORCPT ); Thu, 27 Jul 2023 16:47:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231570AbjG0Uq4 (ORCPT ); Thu, 27 Jul 2023 16:46:56 -0400 Received: from mail-lj1-x232.google.com (mail-lj1-x232.google.com [IPv6:2a00:1450:4864:20::232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6597271D for ; Thu, 27 Jul 2023 13:46:33 -0700 (PDT) Received: by mail-lj1-x232.google.com with SMTP id 38308e7fff4ca-2b701e1ca63so21959291fa.1 for ; Thu, 27 Jul 2023 13:46:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1690490792; x=1691095592; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=oaqNw2Hm1guEkvjK0qvKkO1TrGxzTe44nwo0h0OS4xY=; b=Qh4G5pkJ2CklC1dn5cBz4RJXwctIF25YGEWE2oQ3ZrOzxnKalFKae/8pznmb31lV7C WTzPyronTTWL8g0r5I8lSbz/AdU7gvJCGq8K2Qd4vWzRvFiQ/FfCwXl6dsQ9CmNizTh+ m0AH/lVmLiMfUecg6qsdvv9XMrT/D7wOGOTWcG9Zt50oRSe1Bavo9Ko7yaB4wjJ+Qnnr BNWwV0vvSuj9U4WuwZrl1x2sIhyQwELI33CtL1QqIzp+Rtzz205zsveFrvcH9XBhLeZX G7lPHvXhJp/f1c2Jmw7kl1BPg6BGcbtzSnM+LE3IJIaKxCmCB8OfQyprqC6Rh3SHBpsg Wpxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690490792; x=1691095592; 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=oaqNw2Hm1guEkvjK0qvKkO1TrGxzTe44nwo0h0OS4xY=; b=cIWRrNJAxXNGf/cCZhI/WhleJ19H1lVTspF1KEz1+LkNa+BpyAJ+m7YXZSFRX8KH8d pneT9TvEiEmnUN16gKM9HWiLhanRdxidkvdlBx83NWaPgWc7MHxjiNinmoXPLKkoH6fB vzWqrEoM4yFn/SvLONJh7akI9MvWdrNPRS1PNOrGiimjXAJ2F/sWASw2/7LTPI7dnEwF ucIZ/UfvzsJQzMCnPHlc9B4/CNQJA19qkYKkZgHwELSTZ0F8vBGofPZxVfybIitiO6SH IfmZh99jDUMozxHvz5OpiwSAuTAW6R2XGEZ2GUspB2NvXC2BhFijze1zaKQarx1M7mNO VwSA== X-Gm-Message-State: ABy/qLZgHUZWAldkarwnuXffsAWSX4T5nA+KGPwAlHXFCiUCjrncRqVT zta/RDF8HM2Gb6VMjtJo1WXDyg== X-Google-Smtp-Source: APBJJlEpvm0P4NAPU6V060zctU8cT38iuWapH30/cDkVR/gUSQA0rrC4oV9wP9Dr8ocbwFl306QznA== X-Received: by 2002:a05:651c:1042:b0:2b6:da64:321 with SMTP id x2-20020a05651c104200b002b6da640321mr95486ljm.45.1690490792019; Thu, 27 Jul 2023 13:46:32 -0700 (PDT) Received: from localhost.localdomain ([2a02:6b6a:b465:0:7e3e:db9e:70fa:9ccb]) by smtp.gmail.com with ESMTPSA id k1-20020a7bc401000000b003fc06169abdsm2701400wmi.2.2023.07.27.13.46.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Jul 2023 13:46:31 -0700 (PDT) From: Usama Arif To: linux-mm@kvack.org, muchun.song@linux.dev, mike.kravetz@oracle.com, rppt@kernel.org Cc: linux-kernel@vger.kernel.org, fam.zheng@bytedance.com, liangma@liangbit.com, simon.evans@bytedance.com, punit.agrawal@bytedance.com, Usama Arif Subject: [v1 1/6] mm: hugetlb: Skip prep of tail pages when HVO is enabled Date: Thu, 27 Jul 2023 21:46:19 +0100 Message-Id: <20230727204624.1942372-2-usama.arif@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230727204624.1942372-1-usama.arif@bytedance.com> References: <20230727204624.1942372-1-usama.arif@bytedance.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" When vmemmap is optimizable, it will free all the duplicated tail pages in hugetlb_vmemmap_optimize while preparing the new hugepage. Hence, there is no need to prepare them. For 1G x86 hugepages, it avoids preparing 262144 - 64 =3D 262080 struct pages per hugepage. Signed-off-by: Usama Arif --- mm/hugetlb.c | 32 +++++++++++++++++++++++--------- mm/hugetlb_vmemmap.c | 2 +- mm/hugetlb_vmemmap.h | 7 +++++++ 3 files changed, 31 insertions(+), 10 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 64a3239b6407..58cf5978bee1 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1943,13 +1943,24 @@ static void prep_new_hugetlb_folio(struct hstate *h= , struct folio *folio, int ni } =20 static bool __prep_compound_gigantic_folio(struct folio *folio, - unsigned int order, bool demote) + unsigned int order, bool demote, + bool hvo) { int i, j; int nr_pages =3D 1 << order; struct page *p; =20 __folio_clear_reserved(folio); + +#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP + /* + * No need to prep pages that will be freed later by hugetlb_vmemmap_opti= mize + * in prep_new_huge_page. Hence, reduce nr_pages to the pages that will b= e kept. + */ + if (hvo) + nr_pages =3D HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page); +#endif + for (i =3D 0; i < nr_pages; i++) { p =3D folio_page(folio, i); =20 @@ -2020,15 +2031,15 @@ static bool __prep_compound_gigantic_folio(struct f= olio *folio, } =20 static bool prep_compound_gigantic_folio(struct folio *folio, - unsigned int order) + unsigned int order, bool hvo) { - return __prep_compound_gigantic_folio(folio, order, false); + return __prep_compound_gigantic_folio(folio, order, false, hvo); } =20 static bool prep_compound_gigantic_folio_for_demote(struct folio *folio, - unsigned int order) + unsigned int order, bool hvo) { - return __prep_compound_gigantic_folio(folio, order, true); + return __prep_compound_gigantic_folio(folio, order, true, hvo); } =20 /* @@ -2185,7 +2196,8 @@ static struct folio *alloc_fresh_hugetlb_folio(struct= hstate *h, if (!folio) return NULL; if (hstate_is_gigantic(h)) { - if (!prep_compound_gigantic_folio(folio, huge_page_order(h))) { + if (!prep_compound_gigantic_folio(folio, huge_page_order(h), + vmemmap_should_optimize(h, &folio->page))) { /* * Rare failure to convert pages to compound page. * Free pages and try again - ONCE! @@ -3201,7 +3213,8 @@ static void __init gather_bootmem_prealloc(void) =20 VM_BUG_ON(!hstate_is_gigantic(h)); WARN_ON(folio_ref_count(folio) !=3D 1); - if (prep_compound_gigantic_folio(folio, huge_page_order(h))) { + if (prep_compound_gigantic_folio(folio, huge_page_order(h), + vmemmap_should_optimize(h, page))) { WARN_ON(folio_test_reserved(folio)); prep_new_hugetlb_folio(h, folio, folio_nid(folio)); free_huge_page(page); /* add to the hugepage allocator */ @@ -3624,8 +3637,9 @@ static int demote_free_hugetlb_folio(struct hstate *h= , struct folio *folio) subpage =3D folio_page(folio, i); inner_folio =3D page_folio(subpage); if (hstate_is_gigantic(target_hstate)) - prep_compound_gigantic_folio_for_demote(inner_folio, - target_hstate->order); + prep_compound_gigantic_folio_for_demote(folio, + target_hstate->order, + vmemmap_should_optimize(target_hstate, subpage)); else prep_compound_page(subpage, target_hstate->order); folio_change_private(inner_folio, NULL); diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index c2007ef5e9b0..b721e87de2b3 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -486,7 +486,7 @@ int hugetlb_vmemmap_restore(const struct hstate *h, str= uct page *head) } =20 /* Return true iff a HugeTLB whose vmemmap should and can be optimized. */ -static bool vmemmap_should_optimize(const struct hstate *h, const struct p= age *head) +bool vmemmap_should_optimize(const struct hstate *h, const struct page *he= ad) { if (!READ_ONCE(vmemmap_optimize_enabled)) return false; diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h index 25bd0e002431..07555d2dc0cb 100644 --- a/mm/hugetlb_vmemmap.h +++ b/mm/hugetlb_vmemmap.h @@ -13,6 +13,7 @@ #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head); void hugetlb_vmemmap_optimize(const struct hstate *h, struct page *head); +bool vmemmap_should_optimize(const struct hstate *h, const struct page *he= ad); =20 /* * Reserve one vmemmap page, all vmemmap addresses are mapped to it. See @@ -51,6 +52,12 @@ static inline unsigned int hugetlb_vmemmap_optimizable_s= ize(const struct hstate { return 0; } + +bool vmemmap_should_optimize(const struct hstate *h, const struct page *he= ad) +{ + return false; +} + #endif /* CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP */ =20 static inline bool hugetlb_vmemmap_optimizable(const struct hstate *h) --=20 2.25.1