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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_NONE,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 46AF2C4742C for ; Fri, 13 Nov 2020 11:07:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAF7020797 for ; Fri, 13 Nov 2020 11:07:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bytedance-com.20150623.gappssmtp.com header.i=@bytedance-com.20150623.gappssmtp.com header.b="QulP4xf/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726527AbgKMLHu (ORCPT ); Fri, 13 Nov 2020 06:07:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726334AbgKMLFt (ORCPT ); Fri, 13 Nov 2020 06:05:49 -0500 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66A34C094242 for ; Fri, 13 Nov 2020 03:04:08 -0800 (PST) Received: by mail-pf1-x442.google.com with SMTP id y7so7306989pfq.11 for ; Fri, 13 Nov 2020 03:04:08 -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=fI+ffyIJ/lWFcSPqbFf/SmboYz3zeHAfd7luhLQKQ2M=; b=QulP4xf/F6bZj2Zxu1813MvOIxpc2rFiP4TBkEPNGz0cA8cZfezugMTjZ1JRHyAQPK +YUUWrYNgbVdX27QXnFjI6qj01jwtydS7G7T061gSxs//krrWqRIAABtWkIYNR0lykl5 TdLs0L4qv6nPhkfMKYbDMbbPWCIHbDIohnT86/1voKVq0HpLeRh49n5lPp4FwnlRjWhy qM+1w2MIzt6mat1Ecs5s8/gbvmVB3nSl3JyAq2dMBiV187YaVB+wTY+OFHRBNibHqweP ztz7ULVEjVJpEVz5+uq+rgoj7N1H9erXAjIw1ObKzX+WeTY033M2B0NZRD5OWfuRcTGQ hp2Q== 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=fI+ffyIJ/lWFcSPqbFf/SmboYz3zeHAfd7luhLQKQ2M=; b=SodqWuv9zbdHXLHu4+BGOtwn7Yi8wCcflw+PptuK2gKe7bYcAWY9c2UEn/ZC/SImZ+ vnKTxMj/YzhLAQnEaZOgYQWhyjM++ByQc6+HERq3QxjPJYo5+ATZVme4q755eOHxjUme HIyKkxegsuZk6UporkKb+Isb+DuE029ff31RMtFJ2ls0M6rjZkJubIzTR8nbi+FTfHUI vfAAXWu6DbamcILFrsJzyMtRqOiMkOc494NaZrD9mBhbcUq5z2C/9Qlpg2B90xI8AziQ SybIqrTSc12UYPFgViSszM9m9UF4M8xGKAKbeAbt+Su4Rvvru9C3v3JHVrlv0bHsYLRp YmfA== X-Gm-Message-State: AOAM533yrnmOEdpIOpGYV6PfsYMemJ4d7iIBKHexXzV3q/AihocaYjqb SBVCde/t2QJc8MvTv4lshySvJw== X-Google-Smtp-Source: ABdhPJycK8Y8+LhZZx+UnepZGWXv3ZrX0BXb/re7wsijJy2j7WEjgUHiRaeIGY1XCDVXSaWuN3Ls6w== X-Received: by 2002:a65:56ca:: with SMTP id w10mr1741133pgs.204.1605265447958; Fri, 13 Nov 2020 03:04:07 -0800 (PST) Received: from localhost.localdomain ([61.120.150.78]) by smtp.gmail.com with ESMTPSA id f1sm8909959pfc.56.2020.11.13.03.03.57 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 13 Nov 2020 03:04:07 -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 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 v4 17/21] mm/hugetlb: Add a kernel parameter hugetlb_free_vmemmap Date: Fri, 13 Nov 2020 18:59:48 +0800 Message-Id: <20201113105952.11638-18-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20201113105952.11638-1-songmuchun@bytedance.com> References: <20201113105952.11638-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a kernel parameter hugetlb_free_vmemmap to disable the feature of freeing unused vmemmap pages associated with each hugetlb page on boot. Signed-off-by: Muchun Song --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ mm/hugetlb_vmemmap.c | 22 ++++++++++++++++++++++ 3 files changed, 34 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 5debfe238027..ccf07293cb63 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1551,6 +1551,15 @@ Documentation/admin-guide/mm/hugetlbpage.rst. Format: size[KMG] + hugetlb_free_vmemmap= + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, + this controls freeing unused vmemmap pages associated + with each HugeTLB page. + Format: { on (default) | off } + + on: enable the feature + off: disable the feature + hung_task_panic= [KNL] Should the hung task detector generate panics. Format: 0 | 1 diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst index f7b1c7462991..7d6129ee97dd 100644 --- a/Documentation/admin-guide/mm/hugetlbpage.rst +++ b/Documentation/admin-guide/mm/hugetlbpage.rst @@ -145,6 +145,9 @@ default_hugepagesz will all result in 256 2M huge pages being allocated. Valid default huge page size is architecture dependent. +hugetlb_free_vmemmap + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this disables freeing + unused vmemmap pages associated each HugeTLB page. When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` indicates the current number of pre-allocated huge pages of the default size. diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 47f81e0b3832..1528b156920c 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -118,6 +118,22 @@ static inline bool vmemmap_pmd_huge(pmd_t *pmd) } #endif +static bool hugetlb_free_vmemmap_disabled __initdata; + +static int __init early_hugetlb_free_vmemmap_param(char *buf) +{ + if (!buf) + return -EINVAL; + + if (!strcmp(buf, "off")) + hugetlb_free_vmemmap_disabled = true; + else if (strcmp(buf, "on")) + return -EINVAL; + + return 0; +} +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); + static inline unsigned int vmemmap_pages_per_hpage(struct hstate *h) { return free_vmemmap_pages_per_hpage(h) + RESERVE_VMEMMAP_NR; @@ -505,6 +521,12 @@ void __init hugetlb_vmemmap_init(struct hstate *h) unsigned int order = huge_page_order(h); unsigned int vmemmap_pages; + if (hugetlb_free_vmemmap_disabled) { + h->nr_free_vmemmap_pages = 0; + pr_info("disable free vmemmap pages for %s\n", h->name); + return; + } + vmemmap_pages = ((1 << order) * sizeof(struct page)) >> PAGE_SHIFT; /* * The head page and the first tail page are not to be freed to buddy -- 2.11.0