From patchwork Wed Sep 16 00:09:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 263848 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=-9.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 20DC2C433E2 for ; Wed, 16 Sep 2020 00:10:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CAD6B20739 for ; Wed, 16 Sep 2020 00:10:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600215000; bh=hYZK/bgXFqVldxBI+j0G33gBSXVhJ4Kam8PoUuSeBW4=; h=Date:From:To:Subject:List-ID:From; b=pedVxF7FTsSTRWgtFCs2X2wK0pV3IuT9bVjXFx+en5BAT/jIxUaxKrXBvMybUtllK C+CUFWLRX7V0n15EQe93yFmtyeAGk9sTKgjiy21BNQs42yxpAhHPV4Dv6/NEe1K07g iL+WDzYoDqQlNH6EyPN4+gRUG6wz7vbPo07qigA8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727345AbgIPAJ4 (ORCPT ); Tue, 15 Sep 2020 20:09:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:56264 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727142AbgIPAJv (ORCPT ); Tue, 15 Sep 2020 20:09:51 -0400 Received: from X1 (unknown [67.22.170.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C736220739; Wed, 16 Sep 2020 00:09:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600214990; bh=hYZK/bgXFqVldxBI+j0G33gBSXVhJ4Kam8PoUuSeBW4=; h=Date:From:To:Subject:From; b=r1Xm0J+hFz+0UP3k8b8ieGFThd2AC+PYwMMPGdTi3CM8SxJcuoD0jMuINbbTxmuDq mWDGYzGUooxsaouh7s5gg7cYTB3JVkMwB0oKr1+NqqW8HU+bbknZoA73lYz6AJFqud uD6lgfHveefYgpTztW8fTdf4eKsKqCOwKkOgvFUI= Date: Tue, 15 Sep 2020 17:09:48 -0700 From: akpm@linux-foundation.org To: mm-commits@vger.kernel.org, stable@vger.kernel.org, songliubraving@fb.com, pasha.tatashin@soleen.com, oleg@redhat.com, mhocko@suse.com, kirill.shutemov@linux.intel.com, apais@microsoft.com, aarcange@redhat.com, vijayb@linux.microsoft.com Subject: + mm-khugepaged-recalculate-min_free_kbytes-after-memory-hotplug-as-expected-by-khugepaged.patch added to -mm tree Message-ID: <20200916000948.N0vvr%akpm@linux-foundation.org> User-Agent: s-nail v14.9.10 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged has been added to the -mm tree. Its filename is mm-khugepaged-recalculate-min_free_kbytes-after-memory-hotplug-as-expected-by-khugepaged.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-khugepaged-recalculate-min_free_kbytes-after-memory-hotplug-as-expected-by-khugepaged.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-khugepaged-recalculate-min_free_kbytes-after-memory-hotplug-as-expected-by-khugepaged.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Vijay Balakrishna Subject: mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged When memory is hotplug added or removed the min_free_kbytes must 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 leaves the system with small min_free_kbytes which isn't suitable for systems especially with network intensive loads. Typical failure symptoms include HW WATCHDOG reset, soft lockup hang notices, NETDEVICE WATCHDOG timeouts, and OOM process kills. Link: https://lkml.kernel.org/r/1600204258-13683-1-git-send-email-vijayb@linux.microsoft.com Fixes: f000565adb77 ("thp: set recommended min free kbytes") Signed-off-by: Vijay Balakrishna Reviewed-by: Pavel Tatashin Cc: Allen Pais Cc: Andrea Arcangeli Cc: "Kirill A. Shutemov" Cc: Michal Hocko Cc: Oleg Nesterov Cc: Song Liu Cc: Signed-off-by: Andrew Morton --- include/linux/khugepaged.h | 5 +++++ mm/khugepaged.c | 13 +++++++++++-- mm/memory_hotplug.c | 3 +++ 3 files changed, 19 insertions(+), 2 deletions(-) --- a/include/linux/khugepaged.h~mm-khugepaged-recalculate-min_free_kbytes-after-memory-hotplug-as-expected-by-khugepaged +++ a/include/linux/khugepaged.h @@ -15,6 +15,7 @@ extern int __khugepaged_enter(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_t unsigned long addr) { } + +static inline void khugepaged_min_free_kbytes_update(void) +{ +} #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif /* _LINUX_KHUGEPAGED_H */ --- a/mm/khugepaged.c~mm-khugepaged-recalculate-min_free_kbytes-after-memory-hotplug-as-expected-by-khugepaged +++ a/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_kby 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 @@ fail: 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); +} --- a/mm/memory_hotplug.c~mm-khugepaged-recalculate-min_free_kbytes-after-memory-hotplug-as-expected-by-khugepaged +++ a/mm/memory_hotplug.c @@ -36,6 +36,7 @@ #include #include #include +#include #include @@ -857,6 +858,7 @@ int __ref online_pages(unsigned long pfn zone_pcp_update(zone); init_per_zone_wmark_min(); + khugepaged_min_free_kbytes_update(); kswapd_run(nid); kcompactd_run(nid); @@ -1614,6 +1616,7 @@ static int __ref __offline_pages(unsigne pgdat_resize_unlock(zone->zone_pgdat, &flags); init_per_zone_wmark_min(); + khugepaged_min_free_kbytes_update(); if (!populated_zone(zone)) { zone_pcp_reset(zone);