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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 E30E3C54E4B for ; Mon, 11 May 2020 11:27:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A807920722 for ; Mon, 11 May 2020 11:27:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A807920722 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=canonical.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 47320900033; Mon, 11 May 2020 07:27:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3FD8E900006; Mon, 11 May 2020 07:27:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C510900033; Mon, 11 May 2020 07:27:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0215.hostedemail.com [216.40.44.215]) by kanga.kvack.org (Postfix) with ESMTP id 10BAB900006 for ; Mon, 11 May 2020 07:27:08 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 77FC3181AEF09 for ; Mon, 11 May 2020 11:27:07 +0000 (UTC) X-FDA: 76804211694.04.soda78_3e245acb98b08 X-HE-Tag: soda78_3e245acb98b08 X-Filterd-Recvd-Size: 4116 Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Mon, 11 May 2020 11:27:06 +0000 (UTC) Received: from mail-ed1-f70.google.com ([209.85.208.70]) by youngberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jY6aP-0005ZR-Ev for linux-mm@kvack.org; Mon, 11 May 2020 11:27:05 +0000 Received: by mail-ed1-f70.google.com with SMTP id k21so579002edq.13 for ; Mon, 11 May 2020 04:27:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6s913c52qXog287G0uRKNKSekm/u+OcHV1ByehHSyNs=; b=nUN2lAzQ0VB716EUD9xaLCdsj29T49Q9GToqEdlyxHJpkPFBi8VnBe8m7zzjDhVxm2 f3Ie9RvqUbXfo+F95zN5zLAlCA06sDr2w2lOCuawzEChKOzW/nM7o7TrK9wkka7V+Xh5 scH/Mexnax1SU7apxAiQerAWEFPpw5BJME5/BGlT5ObCsC4N/qhzT+1ljlYDhIa4ta/+ iLYq7a9ivHG1qW1ABOirpLJjeuW0ktmlEy0FTcXlZBTIK6kyx4xTP85Dd2LmS8nlFG3J Zs3Oa6DaTaQBrp4knstvCQZRa1PIJlcEbsB/t571sX3jIYfq9wwBRUtITZ3QT5RYLWS1 8vJQ== X-Gm-Message-State: AGi0Pua1xKFBajGHhiFbcKjgOSaym9kz27UDfIQG8zj8Yr/qAWepGt/c F4DoxkxgQHGoafCoLqVuajqc1MILK/Uz+qNzvKmUB0dN9VuNd8hq3YPijidSiGjUmUafupdN7AJ GgtPk8yddavpHhkQt4SZTQ9SwuUvctM5CkUMuGcRfDPN2 X-Received: by 2002:a17:906:e098:: with SMTP id gh24mr13250452ejb.44.1589196425146; Mon, 11 May 2020 04:27:05 -0700 (PDT) X-Google-Smtp-Source: APiQypJK5vYrawWYQ4rT6+ywp/xCU6lU3xhBAyIqYrYAMAAN44ZPbDkRzW2yvynqnjzplQWrqO23kmx5LdF727eZk+s= X-Received: by 2002:a17:906:e098:: with SMTP id gh24mr13250440ejb.44.1589196424851; Mon, 11 May 2020 04:27:04 -0700 (PDT) MIME-Version: 1.0 References: <20200507215946.22589-1-gpiccoli@canonical.com> <20200507160438.ed336a1e00c23c6863d75ae5@linux-foundation.org> In-Reply-To: From: Guilherme Piccoli Date: Mon, 11 May 2020 08:26:28 -0300 Message-ID: Subject: Re: [PATCH] mm, compaction: Indicate when compaction is manually triggered by sysctl To: David Rientjes Cc: "Guilherme G. Piccoli" , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Gavin Guo , Mel Gorman Content-Type: text/plain; charset="UTF-8" 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 Sun, May 10, 2020 at 10:25 PM David Rientjes wrote: > [...] > The kernel log is not preferred for this (or drop_caches, really) because > the amount of info can causing important information to be lost. We don't > really gain anything by printing that someone manually triggered > compaction; they could just write to the kernel log themselves if they > really wanted to. The reverse is not true: we can't suppress your kernel > message with this patch. > > Instead, a statsfs-like approach could be used to indicate when this has > happened and there is no chance of losing events because it got scrolled > off the kernel log. It has the added benefit of not requiring the entire > log to be parsed for such events. OK, agreed! Let's forget the kernel log. So, do you think the way to go is the statsfs, not a zoneinfo stat, a per-node thing? I'm saying that because kernel mm subsystem statistics seem pretty.."comfortable" the way they are, in files like vmstat, zoneinfo, etc. Let me know your thoughts on this, if I could work on that or should wait statsfs. Thanks, Guilherme