From mboxrd@z Thu Jan 1 00:00:00 1970 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 BD9CECCA47B for ; Mon, 13 Jun 2022 06:35:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235589AbiFMGfk (ORCPT ); Mon, 13 Jun 2022 02:35:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234610AbiFMGfd (ORCPT ); Mon, 13 Jun 2022 02:35:33 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37950BC81 for ; Sun, 12 Jun 2022 23:35:32 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id y13-20020a17090a154d00b001eaaa3b9b8dso2167947pja.2 for ; Sun, 12 Jun 2022 23:35:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=B72Ua44K+e6NGA36blstxa09i97avcKmfrwwXvB2UR0=; b=qwkYRnZuS/W9slMWkIAwYldruSCyscLX8/wyF7kLD8G4uAeT2sqkPMDJ9FLteGBkba jPtSNz9K5I6n2/vLHYGNDpiJsEr6w0AdooLipoVAUAZ8Y4EBOxLw9+mQhljpgwFEQzqf yztz6xnzmXcan/IcMsTOWEk5Pil7u0lNfnQePAdqkP+93elHBvBPF44pEJT1wFoWpLse 3kVLIYgT3gyvTFurcJnYDGckq9NnRYCNM90frf7MuhOYmtrIXMfiKNc7i4JsrOf8flV7 yS3Q7pWIirK0dCxNgn28AalTjpfE0oz8lfmYe0RuwZiDGEikCM0cN6ykGA39pbDhQ8x8 Fgew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=B72Ua44K+e6NGA36blstxa09i97avcKmfrwwXvB2UR0=; b=e8EAbUM06WgrF/va5WMIkTGZZ0FAod6Wrkr7ORrws+aj2IFMwTjZiWccvnrQecVRQu 3jwZOPvUdt/MGP4CL1bI0Qyi1EUtMlXzXvV/1HCqTJp3u26n0U4RpR30DZT9Fqbp2dhr bUOYuKU6xc6T0VWAsXVuUSin0YYeVA/RoUfAnPbtn1urKzifdH97urYJ8796k4dmQ4o4 +rK0/pYdB5muhwkzb3A3SI7lGMWONSlvqGtSacDYkYLMeuoSTLantONuOUqOIsB4CP/V WyI8a/e/XJSXn+Zjm/L3vnZmWodbc5Th0h10ygZ1In5eUbwj3hp7arzbx8UB+e46600+ 79MA== X-Gm-Message-State: AOAM530w8CZSw1vuhnDUmDzV6tJWTcPGnhXIcDP6yaj9JbAAlgZZcONq rRDRx1qURJ1z5y0hkO+/NvqJUdQznQgGJ2KFiyk= X-Google-Smtp-Source: ABdhPJy8ePrJh8eNpFPc7r+hoH67PAyb+LUzYIz//Skci1r3NK3WQ1UlwXpoXXJMTLqE6uQnUgUeXg== X-Received: by 2002:a17:902:d2c9:b0:167:1195:3a41 with SMTP id n9-20020a170902d2c900b0016711953a41mr51441419plc.126.1655102131696; Sun, 12 Jun 2022 23:35:31 -0700 (PDT) Received: from FVFYT0MHHV2J.bytedance.net ([139.177.225.255]) by smtp.gmail.com with ESMTPSA id v3-20020aa799c3000000b0051bc538baadsm4366554pfi.184.2022.06.12.23.35.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 12 Jun 2022 23:35:31 -0700 (PDT) From: Muchun Song To: mike.kravetz@oracle.com, david@redhat.com, akpm@linux-foundation.org, corbet@lwn.net Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Muchun Song , Catalin Marinas , Will Deacon , Anshuman Khandual Subject: [PATCH 1/6] mm: hugetlb_vmemmap: delete hugetlb_optimize_vmemmap_enabled() Date: Mon, 13 Jun 2022 14:35:07 +0800 Message-Id: <20220613063512.17540-2-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.1 (Apple Git-133) In-Reply-To: <20220613063512.17540-1-songmuchun@bytedance.com> References: <20220613063512.17540-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The name hugetlb_optimize_vmemmap_enabled() a bit confusing as it tests two conditions (enabled and pages in use). Instead of coming up to an appropriate name, we could just delete it. There is already a discussion about deleting it in thread [1]. There is only one user of hugetlb_optimize_vmemmap_enabled() outside of hugetlb_vmemmap, that is flush_dcache_page() in arch/arm64/mm/flush.c. However, it does not need to call hugetlb_optimize_vmemmap_enabled() in flush_dcache_page() since HugeTLB pages are always fully mapped and only head page will be set PG_dcache_clean meaning only head page's flag may need to be cleared (see commit cf5a501d985b). So it is easy to remove hugetlb_optimize_vmemmap_enabled(). Link: https://lore.kernel.org/all/c77c61c8-8a5a-87e8-db89-d04d8aaab4cc@oracle.com/ [1] Signed-off-by: Muchun Song Cc: Catalin Marinas Cc: Will Deacon Cc: Anshuman Khandual --- arch/arm64/mm/flush.c | 13 +++---------- include/linux/page-flags.h | 14 ++------------ 2 files changed, 5 insertions(+), 22 deletions(-) diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index fc4f710e9820..5f9379b3c8c8 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -76,17 +76,10 @@ EXPORT_SYMBOL_GPL(__sync_icache_dcache); void flush_dcache_page(struct page *page) { /* - * Only the head page's flags of HugeTLB can be cleared since the tail - * vmemmap pages associated with each HugeTLB page are mapped with - * read-only when CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP is enabled (more - * details can refer to vmemmap_remap_pte()). Although - * __sync_icache_dcache() only set PG_dcache_clean flag on the head - * page struct, there is more than one page struct with PG_dcache_clean - * associated with the HugeTLB page since the head vmemmap page frame - * is reused (more details can refer to the comments above - * page_fixed_fake_head()). + * HugeTLB pages are always fully mapped and only head page will be + * set PG_dcache_clean (see comments in __sync_icache_dcache()). */ - if (hugetlb_optimize_vmemmap_enabled() && PageHuge(page)) + if (PageHuge(page)) page = compound_head(page); if (test_bit(PG_dcache_clean, &page->flags)) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index de80f0c26b2f..b8b992cb201c 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -203,12 +203,6 @@ enum pageflags { DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, hugetlb_optimize_vmemmap_key); -static __always_inline bool hugetlb_optimize_vmemmap_enabled(void) -{ - return static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, - &hugetlb_optimize_vmemmap_key); -} - /* * If the feature of optimizing vmemmap pages associated with each HugeTLB * page is enabled, the head vmemmap page frame is reused and all of the tail @@ -227,7 +221,8 @@ static __always_inline bool hugetlb_optimize_vmemmap_enabled(void) */ static __always_inline const struct page *page_fixed_fake_head(const struct page *page) { - if (!hugetlb_optimize_vmemmap_enabled()) + if (!static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, + &hugetlb_optimize_vmemmap_key)) return page; /* @@ -255,11 +250,6 @@ static inline const struct page *page_fixed_fake_head(const struct page *page) { return page; } - -static inline bool hugetlb_optimize_vmemmap_enabled(void) -{ - return false; -} #endif static __always_inline int page_is_fake_head(struct page *page) -- 2.11.0