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=-18.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 D19E0C433E2 for ; Tue, 15 Sep 2020 19:32:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 50AA120770 for ; Tue, 15 Sep 2020 19:32:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="n1Hhv5oM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 50AA120770 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 93B5890003E; Tue, 15 Sep 2020 15:31:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8EC58900028; Tue, 15 Sep 2020 15:31:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8291C90003E; Tue, 15 Sep 2020 15:31:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0148.hostedemail.com [216.40.44.148]) by kanga.kvack.org (Postfix) with ESMTP id 6E673900028 for ; Tue, 15 Sep 2020 15:31:59 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 2701B181AEF1E for ; Tue, 15 Sep 2020 19:31:59 +0000 (UTC) X-FDA: 77266291158.13.wash18_511789a27113 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin13.hostedemail.com (Postfix) with ESMTP id EE5B318140B67 for ; Tue, 15 Sep 2020 19:31:58 +0000 (UTC) X-HE-Tag: wash18_511789a27113 X-Filterd-Recvd-Size: 4163 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Tue, 15 Sep 2020 19:31:58 +0000 (UTC) Received: from [192.168.0.121] (unknown [209.134.121.133]) by linux.microsoft.com (Postfix) with ESMTPSA id DE8AE20A0867; Tue, 15 Sep 2020 12:31:56 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com DE8AE20A0867 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1600198317; bh=vEx4iggKRYKKd1K2MkTTPBcXxVR8S1YXGdK8CJ04Tek=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=n1Hhv5oMQqsAKpWmedVfh4jymNsNnG9jc1Eq0s+x2wQZjEq5tFRadOx9kAjKYH03J VuD3VSwBcTphepRh/D53Ml+xHzOQ5QX2Ek2MEp4OI8GQ6cEBloASqrypyjaSEBaVbI wf3kaxNibfKPKmfuc5GDvwxIWfEYJfrsdBFAuGCk= Subject: Re: [v1] mm: khugepaged: avoid overriding min_free_kbytes set by user To: Pavel Tatashin Cc: Andrew Morton , "Kirill A. Shutemov" , Oleg Nesterov , Song Liu , Andrea Arcangeli , Michal Hocko , Allen Pais , LKML , linux-mm References: <1600145748-26518-1-git-send-email-vijayb@linux.microsoft.com> From: Vijay Balakrishna Message-ID: Date: Tue, 15 Sep 2020 12:31:56 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: EE5B318140B67 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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 9/15/2020 11:27 AM, Pavel Tatashin wrote: > On Tue, Sep 15, 2020 at 12:55 AM Vijay Balakrishna > wrote: >> >> set_recommended_min_free_kbytes need to honor min_free_kbytes set by the >> user. Post start-of-day THP enable or memory hotplug operations can >> lose user specified min_free_kbytes, in particular when it is higher than >> calculated recommended value. >> >> Signed-off-by: Vijay Balakrishna >> Cc: stable@vger.kernel.org >> --- >> mm/khugepaged.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/mm/khugepaged.c b/mm/khugepaged.c >> index 4f7107476a6f..b4b753ba411a 100644 >> --- a/mm/khugepaged.c >> +++ b/mm/khugepaged.c >> @@ -2253,7 +2253,7 @@ static void set_recommended_min_free_kbytes(void) >> { >> struct zone *zone; >> int nr_zones = 0; >> - unsigned long recommended_min; >> + int recommended_min; > > Hi Vijay, > > Please explain in log the type change. user_min_free_kbytes is of > "int" type and is initialized to -1, so comparing to unsigned leads to > undesired effect. Hi Pasha, I will update log. I uncovered it when trying to understand why one-line change to address issue raised by Kirill didn't work! > > >> >> for_each_populated_zone(zone) { >> /* >> @@ -2280,12 +2280,12 @@ static void set_recommended_min_free_kbytes(void) >> >> /* don't ever allow to reserve more than 5% of the lowmem */ >> recommended_min = min(recommended_min, >> - (unsigned long) nr_free_buffer_pages() / 20); >> + (int) nr_free_buffer_pages() / 20); >> recommended_min <<= (PAGE_SHIFT-10); >> >> - if (recommended_min > min_free_kbytes) { >> + if (recommended_min > user_min_free_kbytes) { > > Took me a while to understand, but this change is correct. It is the > same logic that is done in init_per_zone_wmark_min(). > > Please join the two patches you have in one patch series. > Reviewed-by: Pavel Tatashin Will do. Thanks, Vijay > > Thank you, > Pasha >