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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1241DECAAD3 for ; Wed, 14 Sep 2022 14:22:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 692E28D0002; Wed, 14 Sep 2022 10:22:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 642DC8D0001; Wed, 14 Sep 2022 10:22:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 509828D0002; Wed, 14 Sep 2022 10:22:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 3ED718D0001 for ; Wed, 14 Sep 2022 10:22:55 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 06C6D1204A3 for ; Wed, 14 Sep 2022 14:22:55 +0000 (UTC) X-FDA: 79910907510.11.D7BD897 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf13.hostedemail.com (Postfix) with ESMTP id 55562200AA for ; Wed, 14 Sep 2022 14:22:54 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6AEE561DD0; Wed, 14 Sep 2022 14:22:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58531C433D6; Wed, 14 Sep 2022 14:22:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663165372; bh=Y6zycBhsCZgK5WNKVxWPiDaovSEbTGuLy5Mn5r3GsUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZSQ3uaCOQMXH5jgxiHuNWDm6VdOWemg6XW+G1Vy3ZYbVuw2sIw8YCmbISVy9JAqmT CpeIudTMBBSxMJmpIrVYJIf8BtfAIy3hWNwK2eDf9czR7E3uW2YV9uNWFy05ie01Rw z2joeyvRn2/CqeQTtkQcyVgdMhhuN08mFc+RLO+zCTHdP9kjnc3nygzFekLx3pnZ8r s8OAYMDrh2Ai3nZY82CdapbTIBNK0JeP0V3PMbcELbfs+mmo7fTrVsEBXzHVJi5jFR RZDowiWJX4V8McliiljPdIFDwhdUphEbtw9lGj5ECobJXwp6JnGJApdU14+tMzmGWl OrBWUZpvbG3AA== From: SeongJae Park To: Xin Hao Cc: sj@kernel.org, akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2] mm/damon: simplify scheme create in lru_sort.c Date: Wed, 14 Sep 2022 14:22:50 +0000 Message-Id: <20220914142250.1269-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220914113859.37637-1-xhao@linux.alibaba.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663165374; a=rsa-sha256; cv=none; b=FwC/QIqSP6cXEtlRfvqlFtfMl8/wPBxQdiyeLNOh5a0K6YRSVCT/ivqC7v8H54VwPBUwfN tOqdq0G0AshGzdS1TtszPs6Tqiw3v7IshcQIC8dYlqITAnzzESCZ69GugwE+SP4jHU8kYk rExsPge+32Mly7jS9XCtnEkASHC1nIU= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ZSQ3uaCO; spf=pass (imf13.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663165374; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=32jlsIIGd+CAxQKAYmCSEjn9Lvyt7veWOungA+VvlEg=; b=YP5yYCVDa7p+H+cHIfm4dT3FPtz8030Q6/nKhn5hb+gOBVwfeNXnOUlEewsLpx7cWEaRG5 rWmMcijNkDp+bQM6eg8VhaunabwoQsO1zZLm0IROpq2UHrUjzy7w1MavksOMDzsUc8j1X7 Jl65OU2XqyZWTupgbPZQV0zbZ7Bl+rg= X-Rspam-User: Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ZSQ3uaCO; spf=pass (imf13.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspamd-Server: rspam02 X-Stat-Signature: pdnmr87536pfi8qxur8jwrdxo6acinhh X-Rspamd-Queue-Id: 55562200AA X-HE-Tag: 1663165374-548736 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: Hi Xin, On Wed, 14 Sep 2022 19:38:59 +0800 Xin Hao wrote: > In damon_lru_sort_new_hot_scheme() and damon_lru_sort_new_cold_scheme(), > they have so much in common, so we can combine them into a single > function, and we just need to distinguish their differences. Thank you again for patiently waiting for my changes and reworking on this! > > Signed-off-by: Xin Hao > --- > mm/damon/lru_sort.c | 57 ++++++++++++++++++++++----------------------- > 1 file changed, 28 insertions(+), 29 deletions(-) > > diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c > index 07a0908963fd..2eac907e866d 100644 > --- a/mm/damon/lru_sort.c > +++ b/mm/damon/lru_sort.c > @@ -135,17 +135,40 @@ DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_lru_sort_cold_stat, > static struct damon_ctx *ctx; > static struct damon_target *target; > > -static struct damos *damon_lru_sort_new_scheme( > - struct damos_access_pattern *pattern, enum damos_action action) > +static struct damos *damon_lru_sort_new_scheme(unsigned int thres, > + enum damos_action action) > { > + struct damos_access_pattern pattern = { > + /* Find regions having PAGE_SIZE or larger size */ > + .min_sz_region = PAGE_SIZE, > + .max_sz_region = ULONG_MAX, > + /* and accessed for more than the threshold */ This comment would be better to be written again? > + .min_nr_accesses = 0, > + .max_nr_accesses = 0, If we're gonna set above two fields anyway later, we could simply remove above three lines. > + /* no matter its age */ > + .min_age_region = 0, > + .max_age_region = UINT_MAX, > + }; > struct damos_quota quota = damon_lru_sort_quota; > > /* Use half of total quota for hot/cold pages sorting */ > quota.ms = quota.ms / 2; > > + switch (action) { > + case DAMOS_LRU_PRIO: > + pattern.min_nr_accesses = thres; > + pattern.max_nr_accesses = UINT_MAX; > + break; > + case DAMOS_LRU_DEPRIO: > + pattern.min_age_region = thres; > + break; > + default: > + return NULL; > + } > + This switch-case makes me wondering if the 'default' case really possible case. I think it would be clearer to set these from caller. IMHO, it might be clearer and shorter to define a static global 'struct damos_access_pattern' stub variable, and make the damon_lru_sort_new_{hot,cold}_scheme() copies it to their local variable, update the relevant fields, and pass that to 'damon_new_scheme()'. What do you think? > return damon_new_scheme( > /* find the pattern, and */ > - pattern, > + &pattern, > /* (de)prioritize on LRU-lists */ > action, > /* under the quota. */ > @@ -157,37 +180,13 @@ static struct damos *damon_lru_sort_new_scheme( > /* Create a DAMON-based operation scheme for hot memory regions */ > static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres) > { > - struct damos_access_pattern pattern = { > - /* Find regions having PAGE_SIZE or larger size */ > - .min_sz_region = PAGE_SIZE, > - .max_sz_region = ULONG_MAX, > - /* and accessed for more than the threshold */ > - .min_nr_accesses = hot_thres, > - .max_nr_accesses = UINT_MAX, > - /* no matter its age */ > - .min_age_region = 0, > - .max_age_region = UINT_MAX, > - }; > - > - return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_PRIO); > + return damon_lru_sort_new_scheme(hot_thres, DAMOS_LRU_PRIO); If we follow what I suggested above, we could make this like below: struct damos_access_pattern pattern = damon_lru_sort_stub_access_pattern; pattern.min_nr_accesses = hot_thres; return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_PRIO); > } > > /* Create a DAMON-based operation scheme for cold memory regions */ > static struct damos *damon_lru_sort_new_cold_scheme(unsigned int cold_thres) > { > - struct damos_access_pattern pattern = { > - /* Find regions having PAGE_SIZE or larger size */ > - .min_sz_region = PAGE_SIZE, > - .max_sz_region = ULONG_MAX, > - /* and not accessed at all */ > - .min_nr_accesses = 0, > - .max_nr_accesses = 0, > - /* for min_age or more micro-seconds */ > - .min_age_region = cold_thres, > - .max_age_region = UINT_MAX, > - }; > - > - return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_DEPRIO); > + return damon_lru_sort_new_scheme(cold_thres, DAMOS_LRU_DEPRIO); And similarly here. > } > > static int damon_lru_sort_apply_parameters(void) > -- > 2.31.0 > > Thanks, SJ