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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 CC993C33CB3 for ; Tue, 28 Jan 2020 10:50:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 90B0F2468D for ; Tue, 28 Jan 2020 10:50:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="nTDNH8XY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 90B0F2468D Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1DF036B000A; Tue, 28 Jan 2020 05:50:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 18EF06B000C; Tue, 28 Jan 2020 05:50:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0CC146B000E; Tue, 28 Jan 2020 05:50:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0097.hostedemail.com [216.40.44.97]) by kanga.kvack.org (Postfix) with ESMTP id EC5D16B000A for ; Tue, 28 Jan 2020 05:50:09 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 9E10B2C8A for ; Tue, 28 Jan 2020 10:50:09 +0000 (UTC) X-FDA: 76426723338.11.flesh98_58ab49772964d X-HE-Tag: flesh98_58ab49772964d X-Filterd-Recvd-Size: 4697 Received: from smtp-fw-2101.amazon.com (smtp-fw-2101.amazon.com [72.21.196.25]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Tue, 28 Jan 2020 10:50:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1580208609; x=1611744609; h=from:to:cc:subject:date:message-id:in-reply-to: mime-version; bh=WYtCBgBVN8ObAntGrLP9PSwj39O1B410LMI+5OpI30E=; b=nTDNH8XYvUKl0hzaXfJUaJG7iblk5gCxNUulLYXN2goLXts0pgEpZlFz xpoUdDptLQ6d3NdcRvX66fHJIDz470gq997a2s8jwnNETxOzqU3uSlONQ +jOl2EQSJEuBKOGD4nfrGlbUeKCgZS6h0HW1w5j8MrhzVABWQLP4TQ29u A=; IronPort-SDR: 0Hsb+qv42wSiM41C93C4a1LfhcjySaLvJzM+hKrBuLySIDMN7FQIj68NhS/Pw2n8brqfJ6m+/6 U5kUDS2M0P6g== X-IronPort-AV: E=Sophos;i="5.70,373,1574121600"; d="scan'208";a="14547675" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-2b-5bdc5131.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-2101.iad2.amazon.com with ESMTP; 28 Jan 2020 10:50:06 +0000 Received: from EX13MTAUEA002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2b-5bdc5131.us-west-2.amazon.com (Postfix) with ESMTPS id 3B6FFA24EE; Tue, 28 Jan 2020 10:50:05 +0000 (UTC) Received: from EX13D31EUA001.ant.amazon.com (10.43.165.15) by EX13MTAUEA002.ant.amazon.com (10.43.61.77) with Microsoft SMTP Server (TLS) id 15.0.1236.3; Tue, 28 Jan 2020 10:50:04 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.161.74) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Tue, 28 Jan 2020 10:49:56 +0000 From: To: Qian Cai CC: , , SeongJae Park , , , , , , , , , , , , , , , , , Subject: Re: Re: [PATCH v2 0/9] Introduce Data Access MONitor (DAMON) Date: Tue, 28 Jan 2020 11:49:42 +0100 Message-ID: <20200128104942.11419-1-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: (raw) MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.161.74] X-ClientProxiedBy: EX13D39UWA001.ant.amazon.com (10.43.160.54) To EX13D31EUA001.ant.amazon.com (10.43.165.15) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 28 Jan 2020 05:20:35 -0500 Qian Cai wrote: > > > > On Jan 28, 2020, at 3:58 AM, sjpark@amazon.com wrote: > > > > This patchset introduces a new kernel module for practical monitoring of data > > accesses, namely DAMON. > > > > The patches are organized in the following sequence. The first four patches > > implements the core logic of DAMON one by one. After that, the fifth patch > > implements DAMON's debugfs interface for users. To provide a minimal reference > > to the low level interface and for more convenient use/tests of the DAMON, the > > sixth patch implements an user space tool. The seventh patch adds a document > > for administrators of DAMON, and the eightth patch provides DAMON's kunit > > tests. Finally, the ninth patch implements a tracepoint for DAMON. As the > > tracepoint prints every monitoring results, it will be easily integrated with > > other tracers supporting tracepoints including perf. > > I am a bit surprised that this patchset did not include perf maintainers which makes me wonder if there is any attempt to discuss first if we actually need a whole new subsystem for it or a existing tool can be enhanced. For the comments from perf maintainers, I added Steven Rostedt and Arnaldo Carvalho de Melo first, but I might missed someone. If you recommend some more people, I will add them to recipients. I made DAMON as a new subsystem because I think no existing subsystem fits well to be a base of DAMON, due to DAMON's unique goals and mechanisms described below in the original cover letter. The existing subsystem that most similar to DAMON might be 'mm/page_idle.c'. However, there are many conceptual differences with DAMON. One biggest difference I think is the target. 'page_idle' deals with physical page frames while DAMON deals with virtual address of specific processes. Nevertheless, if you have some different opinion, please let me know. Thanks, SeongJae Park