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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 59382C433DF for ; Mon, 18 May 2020 10:05:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 136182070A for ; Mon, 18 May 2020 10:05:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="iCZrtXfg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 136182070A 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 B3B93900003; Mon, 18 May 2020 06:05:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AC4EB900002; Mon, 18 May 2020 06:05:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9B44F900003; Mon, 18 May 2020 06:05:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0246.hostedemail.com [216.40.44.246]) by kanga.kvack.org (Postfix) with ESMTP id 7E55A900002 for ; Mon, 18 May 2020 06:05:22 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3F87F824805A for ; Mon, 18 May 2020 10:05:22 +0000 (UTC) X-FDA: 76829407284.04.drop97_2eceb04b16e21 X-HE-Tag: drop97_2eceb04b16e21 X-Filterd-Recvd-Size: 6462 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Mon, 18 May 2020 10:05:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1589796321; x=1621332321; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=fovQ16L+stcdrxZLgubG+D9JSvkNCqpwdVSTbsWqGSk=; b=iCZrtXfgd1nVb7t5esL+ri3s5V3jD4O9F5GhtRjWKb48dFbfTCjgOXbx CBipDRGFlg6ye52XVYWfZkkc/Rm3ojyyh+K6FIMDWDcs+uaduMEirrxhr WGjo+H9X3Z5pPYJMNtgeV2GHZYBIeuRral+Qu7ODlRCKJ4dlV3tzGil5H w=; IronPort-SDR: 3lposJMuKVyCpsEMqUrjgdlwAlAVRHMJKcJp84bC+EwnzqvOmPc8k5/eixyb14KMVKVdswhMHl IQvKAmHLs2jQ== X-IronPort-AV: E=Sophos;i="5.73,406,1583193600"; d="scan'208";a="44034842" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1a-16acd5e0.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9102.sea19.amazon.com with ESMTP; 18 May 2020 10:05:16 +0000 Received: from EX13MTAUEA002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1a-16acd5e0.us-east-1.amazon.com (Postfix) with ESMTPS id F3738A24A3; Mon, 18 May 2020 10:05:04 +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 15.0.1497.2; Mon, 18 May 2020 10:05:04 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.160.90) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 18 May 2020 10:04:48 +0000 From: SeongJae Park To: CC: SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v12 06/16] mm/damon: Split regions into 3 subregions if necessary Date: Mon, 18 May 2020 12:00:08 +0200 Message-ID: <20200518100018.2293-7-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200518100018.2293-1-sjpark@amazon.com> References: <20200518100018.2293-1-sjpark@amazon.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.160.90] X-ClientProxiedBy: EX13D04UWA003.ant.amazon.com (10.43.160.212) To EX13D31EUA001.ant.amazon.com (10.43.165.15) 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: From: SeongJae Park Suppose that there are a very wide and cold region and a hot region, and both regions are identified by DAMON. And then, the middle small region inside the very wide and cold region becomes hot. DAMON will not be able to identify this new region because the adaptive regions adjustment mechanism splits each region to only two subregions. This commit modifies the logic to split each region to 3 subregions if such corner case is detected. Suggested-by: James Cameron Signed-off-by: SeongJae Park --- mm/damon.c | 51 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 34 insertions(+), 17 deletions(-) diff --git a/mm/damon.c b/mm/damon.c index 6c9581104caf..bbd5b1d921da 100644 --- a/mm/damon.c +++ b/mm/damon.c @@ -650,26 +650,32 @@ static void damon_split_region_at(struct damon_ctx *ctx, damon_insert_region(new, r, damon_next_region(r)); } -/* Split every region in the given task into two randomly-sized regions */ -static void damon_split_regions_of(struct damon_ctx *ctx, struct damon_task *t) +/* Split every region in the given task into 'nr_subs' regions */ +static void damon_split_regions_of(struct damon_ctx *ctx, + struct damon_task *t, int nr_subs) { struct damon_region *r, *next; - unsigned long sz_orig_region, sz_left_region; + unsigned long sz_region, sz_sub = 0; + int i; damon_for_each_region_safe(r, next, t) { - sz_orig_region = r->vm_end - r->vm_start; - - /* - * Randomly select size of left sub-region to be at least - * 10 percent and at most 90% of original region - */ - sz_left_region = ALIGN_DOWN(damon_rand(1, 10) * sz_orig_region - / 10, MIN_REGION); - /* Do not allow blank region */ - if (sz_left_region == 0 || sz_left_region >= sz_orig_region) - continue; - - damon_split_region_at(ctx, r, sz_left_region); + sz_region = r->vm_end - r->vm_start; + + for (i = 0; i < nr_subs - 1 && + sz_region > 2 * MIN_REGION; i++) { + /* + * Randomly select size of left sub-region to be at + * least 10 percent and at most 90% of original region + */ + sz_sub = ALIGN_DOWN(damon_rand(1, 10) * + sz_region / 10, MIN_REGION); + /* Do not allow blank region */ + if (sz_sub == 0 || sz_sub >= sz_region) + continue; + + damon_split_region_at(ctx, r, sz_sub); + sz_region = sz_sub; + } } } @@ -687,14 +693,25 @@ static void kdamond_split_regions(struct damon_ctx *ctx) { struct damon_task *t; unsigned int nr_regions = 0; + static unsigned int last_nr_regions; + int nr_subregions = 2; damon_for_each_task(t, ctx) nr_regions += nr_damon_regions(t); + if (nr_regions > ctx->max_nr_regions / 2) return; + /* If number of regions is not changed, we are maybe in corner case */ + if (last_nr_regions == nr_regions && + nr_regions < ctx->max_nr_regions / 3) + nr_subregions = 3; + damon_for_each_task(t, ctx) - damon_split_regions_of(ctx, t); + damon_split_regions_of(ctx, t, nr_subregions); + + if (!last_nr_regions) + last_nr_regions = nr_regions; } /* -- 2.17.1