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=-20.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 DCE2CC4727C for ; Tue, 29 Sep 2020 16:49:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B8BE206F7 for ; Tue, 29 Sep 2020 16:49:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="hUdJW/nS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728531AbgI2QtR (ORCPT ); Tue, 29 Sep 2020 12:49:17 -0400 Received: from linux.microsoft.com ([13.77.154.182]:35084 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728459AbgI2QtQ (ORCPT ); Tue, 29 Sep 2020 12:49:16 -0400 Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id E32E520B7178; Tue, 29 Sep 2020 09:49:15 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com E32E520B7178 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1601398155; bh=VoA4Wco3c2m6HGnLWkXWsP5OUf5hRyUk46o/cl5i7aQ=; h=From:To:Cc:Subject:Date:From; b=hUdJW/nSES5pDTMMmJeiEdGBEyfk1itLDZGmGvwpMNLhyB/xnBNp2oC0ZoPBs5GVE rGqfjNCeH0+NqZWfo5wgOkrknzPOrP0e77rGhASWAPiF1xQKztqtmgQDz7B3Mh04Bv 4yg9Rn1xAINZBXriG8JmJvIj1cDcLBlkDp0KLxjw= From: Vijay Balakrishna To: Andrew Morton , "Kirill A. Shutemov" , Oleg Nesterov , Song Liu , Andrea Arcangeli , Pavel Tatashin , Vijay Balakrishna , Michal Hocko , Allen Pais Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [v5] mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged Date: Tue, 29 Sep 2020 09:49:13 -0700 Message-Id: <1601398153-5517-1-git-send-email-vijayb@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When memory is hotplug added or removed the min_free_kbytes should be recalculated based on what is expected by khugepaged. Currently after hotplug, min_free_kbytes will be set to a lower default and higher default set when THP enabled is lost. This change restores min_free_kbytes as expected for THP consumers. Fixes: f000565adb77 ("thp: set recommended min free kbytes") Signed-off-by: Vijay Balakrishna Cc: stable@vger.kernel.org Reviewed-by: Pavel Tatashin Acked-by: Michal Hocko --- v4 -> v5 - changelog: must -> should [Michal Hocko] v3 -> v4 - made changes to move khugepaged_min_free_kbytes_update into init_per_zone_wmark_min and rested changes [suggestion from Michal Hocko] [v2 1/2] - removed symptoms references from changelog [v2 2/2] - addressed following issues Michal Hocko raised: . nr_free_buffer_pages can oveflow in int on very large machines . min_free_kbytes can decrease the size theoretically v1 -> v2 -------- - addressed issue Kirill A. Shutemov raised: . changes would override min_free_kbytes set by user include/linux/khugepaged.h | 5 +++++ mm/khugepaged.c | 13 +++++++++++-- mm/page_alloc.c | 3 +++ 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h index bc45ea1efbf7..c941b7377321 100644 --- a/include/linux/khugepaged.h +++ b/include/linux/khugepaged.h @@ -15,6 +15,7 @@ extern int __khugepaged_enter(struct mm_struct *mm); extern void __khugepaged_exit(struct mm_struct *mm); extern int khugepaged_enter_vma_merge(struct vm_area_struct *vma, unsigned long vm_flags); +extern void khugepaged_min_free_kbytes_update(void); #ifdef CONFIG_SHMEM extern void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr); #else @@ -85,6 +86,10 @@ static inline void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) { } + +static inline void khugepaged_min_free_kbytes_update(void) +{ +} #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif /* _LINUX_KHUGEPAGED_H */ diff --git a/mm/khugepaged.c b/mm/khugepaged.c index cfa0dba5fd3b..4f7107476a6f 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -56,6 +56,9 @@ enum scan_result { #define CREATE_TRACE_POINTS #include +static struct task_struct *khugepaged_thread __read_mostly; +static DEFINE_MUTEX(khugepaged_mutex); + /* default scan 8*512 pte (or vmas) every 30 second */ static unsigned int khugepaged_pages_to_scan __read_mostly; static unsigned int khugepaged_pages_collapsed; @@ -2292,8 +2295,6 @@ static void set_recommended_min_free_kbytes(void) int start_stop_khugepaged(void) { - static struct task_struct *khugepaged_thread __read_mostly; - static DEFINE_MUTEX(khugepaged_mutex); int err = 0; mutex_lock(&khugepaged_mutex); @@ -2320,3 +2321,11 @@ int start_stop_khugepaged(void) mutex_unlock(&khugepaged_mutex); return err; } + +void khugepaged_min_free_kbytes_update(void) +{ + mutex_lock(&khugepaged_mutex); + if (khugepaged_enabled() && khugepaged_thread) + set_recommended_min_free_kbytes(); + mutex_unlock(&khugepaged_mutex); +} diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fab5e97dc9ca..ac25d3526fa5 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -69,6 +69,7 @@ #include #include #include +#include #include #include @@ -7891,6 +7892,8 @@ int __meminit init_per_zone_wmark_min(void) setup_min_slab_ratio(); #endif + khugepaged_min_free_kbytes_update(); + return 0; } postcore_initcall(init_per_zone_wmark_min) -- 2.28.0