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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 2A8CDC4360F for ; Fri, 15 Feb 2019 22:09:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA3E8222D0 for ; Fri, 15 Feb 2019 22:09:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=sent.com header.i=@sent.com header.b="VFUKyEKq"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="L9R6iOLb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393487AbfBOWJh (ORCPT ); Fri, 15 Feb 2019 17:09:37 -0500 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:34827 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393452AbfBOWJd (ORCPT ); Fri, 15 Feb 2019 17:09:33 -0500 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 3178C3058; Fri, 15 Feb 2019 17:09:31 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Fri, 15 Feb 2019 17:09:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sent.com; h=from :to:cc:subject:date:message-id:in-reply-to:references:reply-to :mime-version:content-transfer-encoding; s=fm2; bh=Mql9ve4UDV93V XmSDRn0eYbPSMabzYnGVtBZe6Hc3wQ=; b=VFUKyEKqzz/0iG/0dF5ekrZ9RwQod gNG5oHcb2NvSIDd+Rl9isNZlF5VgGKlJ4Olj2aicC4M/9Sn+EoR7fV4DQl3SJUd2 DgWLETjIDsPKPR0OUdEJEURAHMG0FexsIKnOZEuuAZtaZ+xk94F2LsZlJwoKiiMV UUR3X1EpJwT2JHKKicMLPPi6+H7Y3yvc2EZZLXndyFSkRwVsMwKGNOnxV6fldG4e DApV/ZDSmQmUpI90aeLEYN8aFquAr0SUpa0Swn8154uPWdbzgcyeXBQnYqf3tE1o kC5+4JN2B8jhE3zm9mTPJ9n7dgz3QEHhYXy4DI9j9Zmn4a5fH3nRfAKdw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:reply-to:subject :to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm2; bh=Mql9ve4UDV93VXmSDRn0eYbPSMabzYnGVtBZe6Hc3wQ=; b=L9R6iOLb +1fx/XQVSYC4Jd+HRI9FMFrNQAJ2x8avz1sCrPrCicNu0wDk/XmNq/CojPSXTl6X wmQUTCjl7MEjMlmBz2jvN95txuTU8IxNOVLmOhE9GJdpdevWQnli7p6mG0hudAu4 vaOcgB6DH6XFpX0/6PGv1OM/aDZbokapTVvm/+wjJ8oz4DOvHKBYxpEzCp8SYAso 6Li+nN4pM7dz9276IONc2xX7cfy3hx4fgp7dqL0RT14bIqQNLZxtjxKzxo15MD8t 1r/EZwsP3oCmVrgSCsSYMwkmnr9SiNju/BV2HYNBSi4HVaBwle/5G/hqxWO7Fukd HCEMDHd5Idjofg== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedtledruddtjedgudehkecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfhuthenuceurghilhhouhhtmecu fedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvufffkf fojghfrhgggfestdekredtredttdenucfhrhhomhepkghiucgjrghnuceoiihirdihrghn sehsvghnthdrtghomheqnecukfhppedvudeirddvvdekrdduuddvrddvvdenucfrrghrrg hmpehmrghilhhfrhhomhepiihirdihrghnsehsvghnthdrtghomhenucevlhhushhtvghr ufhiiigvpeduke X-ME-Proxy: Received: from nvrsysarch5.nvidia.com (thunderhill.nvidia.com [216.228.112.22]) by mail.messagingengine.com (Postfix) with ESMTPA id 37CFEE46AD; Fri, 15 Feb 2019 17:09:29 -0500 (EST) From: Zi Yan To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Dave Hansen , Michal Hocko , "Kirill A . Shutemov" , Andrew Morton , Vlastimil Babka , Mel Gorman , John Hubbard , Mark Hairgrove , Nitin Gupta , David Nellans , Zi Yan Subject: [RFC PATCH 21/31] mm: thp: 1GB zero page shrinker. Date: Fri, 15 Feb 2019 14:08:46 -0800 Message-Id: <20190215220856.29749-22-zi.yan@sent.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190215220856.29749-1-zi.yan@sent.com> References: <20190215220856.29749-1-zi.yan@sent.com> Reply-To: ziy@nvidia.com MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zi Yan Remove 1GB zero page when we are under memory pressure. Signed-off-by: Zi Yan --- mm/huge_memory.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index bbdbc9ae06bf..41adc103ead1 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -207,6 +207,32 @@ static struct shrinker huge_zero_page_shrinker = { .seeks = DEFAULT_SEEKS, }; +static unsigned long shrink_huge_pud_zero_page_count(struct shrinker *shrink, + struct shrink_control *sc) +{ + /* we can free zero page only if last reference remains */ + return atomic_read(&huge_pud_zero_refcount) == 1 ? HPAGE_PUD_NR : 0; +} + +static unsigned long shrink_huge_pud_zero_page_scan(struct shrinker *shrink, + struct shrink_control *sc) +{ + if (atomic_cmpxchg(&huge_pud_zero_refcount, 1, 0) == 1) { + struct page *zero_page = xchg(&huge_pud_zero_page, NULL); + BUG_ON(zero_page == NULL); + __free_pages(zero_page, compound_order(zero_page)); + return HPAGE_PUD_NR; + } + + return 0; +} + +static struct shrinker huge_pud_zero_page_shrinker = { + .count_objects = shrink_huge_pud_zero_page_count, + .scan_objects = shrink_huge_pud_zero_page_scan, + .seeks = DEFAULT_SEEKS, +}; + #ifdef CONFIG_SYSFS static ssize_t enabled_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) @@ -474,6 +500,9 @@ static int __init hugepage_init(void) err = register_shrinker(&huge_zero_page_shrinker); if (err) goto err_hzp_shrinker; + err = register_shrinker(&huge_pud_zero_page_shrinker); + if (err) + goto err_hpzp_shrinker; err = register_shrinker(&deferred_split_shrinker); if (err) goto err_split_shrinker; @@ -496,6 +525,8 @@ static int __init hugepage_init(void) err_khugepaged: unregister_shrinker(&deferred_split_shrinker); err_split_shrinker: + unregister_shrinker(&huge_pud_zero_page_shrinker); +err_hpzp_shrinker: unregister_shrinker(&huge_zero_page_shrinker); err_hzp_shrinker: khugepaged_destroy(); -- 2.20.1