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=-16.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1,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 B72F6C4727E for ; Fri, 25 Sep 2020 16:32:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5080023888 for ; Fri, 25 Sep 2020 16:32:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="OckwlBNK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5080023888 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CCE4C6B0085; Fri, 25 Sep 2020 12:32:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C7EE2900005; Fri, 25 Sep 2020 12:32:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBBD16B0088; Fri, 25 Sep 2020 12:32:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0049.hostedemail.com [216.40.44.49]) by kanga.kvack.org (Postfix) with ESMTP id A0FA66B0085 for ; Fri, 25 Sep 2020 12:32:03 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 64455181AE869 for ; Fri, 25 Sep 2020 16:32:03 +0000 (UTC) X-FDA: 77302125726.08.mint32_63124e727169 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 422701819E76B for ; Fri, 25 Sep 2020 16:32:03 +0000 (UTC) X-HE-Tag: mint32_63124e727169 X-Filterd-Recvd-Size: 3905 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Fri, 25 Sep 2020 16:32:02 +0000 (UTC) Received: from [192.168.0.121] (unknown [209.134.121.133]) by linux.microsoft.com (Postfix) with ESMTPSA id DBF9A20B7179; Fri, 25 Sep 2020 09:32:00 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com DBF9A20B7179 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1601051521; bh=axHGvPGQ3Uucmw9dJfiXiWiyXRYSF8alJrmu9OrwpnY=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=OckwlBNKRaG9cq0lrITdg3JNuRgehsftGDd9tpS2SU7+hPmZBXBRGCWV2eLZoJW88 8OYn62ojxVtLOn6up6/D07T6Qyy4HJ0U4ftZiCkQ2wloLAaPxs1nkIvhPRqJJ9G1qG Dj8UCOQF3StjUHVzc5Rbp9I9gMzlDodHOgqihPCc= Subject: Re: [v3 1/2] mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged To: Michal Hocko Cc: Andrew Morton , "Kirill A. Shutemov" , Oleg Nesterov , Song Liu , Andrea Arcangeli , Pavel Tatashin , Allen Pais , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <1600305709-2319-1-git-send-email-vijayb@linux.microsoft.com> <1600305709-2319-2-git-send-email-vijayb@linux.microsoft.com> <20200925074215.GA3389@dhcp22.suse.cz> From: Vijay Balakrishna Message-ID: <751cd286-5919-fc0a-21b4-75460934e305@linux.microsoft.com> Date: Fri, 25 Sep 2020 09:31:39 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.2.2 MIME-Version: 1.0 In-Reply-To: <20200925074215.GA3389@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 9/25/2020 12:42 AM, Michal Hocko wrote: > On Wed 16-09-20 18:21:48, Vijay Balakrishna wrote: >> 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 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 > > I am ok with this patch. I am not sure this is worth backporting to > stable trees becasuse this is not a functional bug. Surprising behavior, > yes, but not much more than that. > > Acked-by: Michal Hocko Thanks Michal. > > One minor comment below > [...] >> @@ -857,6 +858,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, >> zone_pcp_update(zone); >> >> init_per_zone_wmark_min(); >> + khugepaged_min_free_kbytes_update(); >> >> kswapd_run(nid); >> kcompactd_run(nid); >> @@ -1600,6 +1602,7 @@ static int __ref __offline_pages(unsigned long start_pfn, >> 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); > > Can we move khugepaged_min_free_kbytes_update into > init_per_zone_wmark_min? If it stays external we might hit the same > problem when somebody else needs to modify min_free_kbytes. Early init > call will be likely too early for khugepaged but that shouldn't matter > AFAICS because it will call khugepaged_min_free_kbytes_update on its > own. Sure, let me take a look and post v4 next week. Thanks, Vijay >