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 X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43FC0C4361B for ; Thu, 10 Dec 2020 04:02:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1EDEA23BC6 for ; Thu, 10 Dec 2020 04:02:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732275AbgLJEAQ (ORCPT ); Wed, 9 Dec 2020 23:00:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732178AbgLJEAJ (ORCPT ); Wed, 9 Dec 2020 23:00:09 -0500 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0DEBC061282 for ; Wed, 9 Dec 2020 19:59:29 -0800 (PST) Received: by mail-pg1-x541.google.com with SMTP id w4so2929541pgg.13 for ; Wed, 09 Dec 2020 19:59:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=t1l4xMSE0KQnA71H//bDmskGduWipXvDa6Vox+ZjNms=; b=hMRBPFb96XJumXLHyGTTwBklAUnIrxY7ck3bVW6zB94E5E1bc8M4k6wRlkORblzegV U5lvw2LfOIBvWm70vSuLDEgphWueRmLtAcavEysLQ5ehechfmSU3Ipi0TQWhQxUh3fHU enQTfmCl5wcAOp4vSyEMwEiXSHozesuQAfXUZ6fBkXFMzThmMoahvOptGtxCChZaB4XP 20mAdPoysLnFwGnxcQGOb5pWjsSUWLErW/qIG10Grlgi3RBcVRbvDii7ytREaV09QuxP 79KAVZ1RimWNnqGRmifxuj5st5dcIkCJG/ehffyI5jMdPmllwYixCXtBDTnsPx3b4BOl kbLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=t1l4xMSE0KQnA71H//bDmskGduWipXvDa6Vox+ZjNms=; b=NlyPuGytiTWTLkaYzhDGjkCzdlrzKLcvwJv00hIlkSkL2q7+FR2yX6NnNxNchb6Cnd B/adncvGXTOhINlpVPJlmH4PKexcs5DKS+CGcfLknlFN0AWksL4QzfBgEsZywLWsJ/40 U2lt6vMat5kQqvfeyEsAi3SpxqgsjPkuGHA5YrWDsvNMfj3KDiL6UYBN6sGT6YBOvI+F hq9dpgf52ZNsMUtn2u1VoyZwU2KSw1GxL1xa2aSronL0UJMhWqBq75Ub/IWm2wJlZCWj RC6a1RY8cBaVK1ftNPpui/99F2h1N45m8cwv+UzANyrZDoU0YxGcMFKG4xAmKBYy+Y25 klXg== X-Gm-Message-State: AOAM533hmy6sHAw6nq0D9w2DHaNLkJ/RGTDnmjrEZrm8lJzbY3fBlxOf aZ9+Sj0Xf2IiHRg1+ZNBB/WXFw== X-Google-Smtp-Source: ABdhPJydwdYQo79U6PP08VNvTBIzTtWxejp8DNMvx8xTTULpe736PdBuGNl589ah44qPUz1qAf8ZKw== X-Received: by 2002:a17:90a:c306:: with SMTP id g6mr5511722pjt.104.1607572769408; Wed, 09 Dec 2020 19:59:29 -0800 (PST) Received: from localhost.localdomain ([103.136.220.85]) by smtp.gmail.com with ESMTPSA id f33sm4266535pgl.83.2020.12.09.19.59.19 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Dec 2020 19:59:28 -0800 (PST) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [PATCH v8 12/12] mm/hugetlb: Optimize the code with the help of the compiler Date: Thu, 10 Dec 2020 11:55:26 +0800 Message-Id: <20201210035526.38938-13-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20201210035526.38938-1-songmuchun@bytedance.com> References: <20201210035526.38938-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org We cannot optimize if a "struct page" crosses page boundaries. If it is true, we can optimize the code with the help of a compiler. When free_vmemmap_pages_per_hpage() returns zero, most functions are optimized by the compiler. Signed-off-by: Muchun Song --- include/linux/hugetlb.h | 3 ++- mm/hugetlb_vmemmap.c | 3 +++ mm/hugetlb_vmemmap.h | 2 +- 3 files changed, 6 insertions(+), 2 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 7295f6b3d55e..adc17765e0e9 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -791,7 +791,8 @@ extern bool hugetlb_free_vmemmap_enabled; static inline bool is_hugetlb_free_vmemmap_enabled(void) { - return hugetlb_free_vmemmap_enabled; + return hugetlb_free_vmemmap_enabled && + is_power_of_2(sizeof(struct page)); } #else static inline bool is_hugetlb_free_vmemmap_enabled(void) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 7f0b9e002be4..819ab9bb9298 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -208,6 +208,9 @@ bool hugetlb_free_vmemmap_enabled; static int __init early_hugetlb_free_vmemmap_param(char *buf) { + if (!is_power_of_2(sizeof(struct page))) + return 0; + if (!buf) return -EINVAL; diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h index 0a1c0d33a316..5f5e90c81cd2 100644 --- a/mm/hugetlb_vmemmap.h +++ b/mm/hugetlb_vmemmap.h @@ -21,7 +21,7 @@ void free_huge_page_vmemmap(struct hstate *h, struct page *head); */ static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h) { - return h->nr_free_vmemmap_pages; + return h->nr_free_vmemmap_pages && is_power_of_2(sizeof(struct page)); } #else static inline void hugetlb_vmemmap_init(struct hstate *h) -- 2.11.0