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=-13.6 required=3.0 tests=BAYES_00,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=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 354FAC41604 for ; Tue, 6 Oct 2020 12:41:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 97951206F7 for ; Tue, 6 Oct 2020 12:41:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="LLc0SMZL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 97951206F7 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 139F66B005D; Tue, 6 Oct 2020 08:41:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 10DC86B0062; Tue, 6 Oct 2020 08:41:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EF3626B0070; Tue, 6 Oct 2020 08:41:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0214.hostedemail.com [216.40.44.214]) by kanga.kvack.org (Postfix) with ESMTP id C4B946B005D for ; Tue, 6 Oct 2020 08:41:08 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 60484181AE86E for ; Tue, 6 Oct 2020 12:41:08 +0000 (UTC) X-FDA: 77341460616.16.crate06_1d08db0271c6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id 3B8491022E233 for ; Tue, 6 Oct 2020 12:41:08 +0000 (UTC) X-HE-Tag: crate06_1d08db0271c6 X-Filterd-Recvd-Size: 7298 Received: from smtp-fw-33001.amazon.com (smtp-fw-33001.amazon.com [207.171.190.10]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Tue, 6 Oct 2020 12:41:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1601988068; x=1633524068; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=uW2wVCE0fdVcJc5KeJb9HPd/tw2Lj3G+kCxi3x3dF+c=; b=LLc0SMZLf7GWhEir0pmN2+3reRHbT0n3H0YXV2/5M7VvE0R4JwNvJ9eA 8ajjYXQA8PJaRYOxFKEFvcM7/V+x/kdEG9rNMOLAsO1fByWo/Sh0Xg8R1 kdzWa3fZvcRSWNfwmcDKvpIBQ3jw+QQx1gh/piYc9aHgtDrewgOuUhYJz I=; X-IronPort-AV: E=Sophos;i="5.77,343,1596499200"; d="scan'208";a="80729222" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-2b-c300ac87.us-west-2.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 06 Oct 2020 12:41:02 +0000 Received: from EX13D31EUA004.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2b-c300ac87.us-west-2.amazon.com (Postfix) with ESMTPS id 7EC9DA241F; Tue, 6 Oct 2020 12:40:50 +0000 (UTC) Received: from u3f2cd687b01c55.ant.amazon.com (10.43.161.237) by EX13D31EUA004.ant.amazon.com (10.43.165.161) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 6 Oct 2020 12:40:32 +0000 From: SeongJae Park To: CC: SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC v15 1/8] mm/damon/core: Account age of target regions Date: Tue, 6 Oct 2020 14:39:24 +0200 Message-ID: <20201006123931.5847-2-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201006123931.5847-1-sjpark@amazon.com> References: <20201006123931.5847-1-sjpark@amazon.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.161.237] X-ClientProxiedBy: EX13D18UWA002.ant.amazon.com (10.43.160.199) To EX13D31EUA004.ant.amazon.com (10.43.165.161) 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 DAMON can be used for data access pattern aware memory management optimizations. For that, users should run DAMON, read the monitoring results, analyze it, plan a new memory management scheme, and apply the new scheme by themselves. It would not be too hard, but still require some level of effort. For complicated cases, this effort is inevitable. That said, in many cases, users would simply want to apply an actions to a memory region of a specific size having a specific access frequency for a specific time. For example, "page out a memory region larger than 100 MiB but having a low access frequency more than 10 minutes", or "Use THP for a memory region larger than 2 MiB having a high access frequency for more than 2 seconds". For such optimizations, users will need to first account the age of each region themselves. To reduce such efforts, this commit implements a simple age account of each region in DAMON. For each aggregation step, DAMON compares the access frequency with that from last aggregation and reset the age of the region if the change is significant. Else, the age is incremented. Also, in case of the merge of regions, the region size-weighted average of the ages is set as the age of merged new region. Signed-off-by: SeongJae Park --- include/linux/damon.h | 10 ++++++++++ mm/damon/core.c | 13 +++++++++++++ 2 files changed, 23 insertions(+) diff --git a/include/linux/damon.h b/include/linux/damon.h index d675ea908a02..696f25e25d95 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -28,12 +28,22 @@ struct damon_addr_range { * @sampling_addr: Address of the sample for the next access check. * @nr_accesses: Access frequency of this region. * @list: List head for siblings. + * @age: Age of this region. + * @last_nr_accesses: Internal value for age calculation. + * + * @age is initially zero, increased for each aggregation interval, and reset + * to zero again if the access frequency is significantly changed. If two + * regions are merged into a new region, both @nr_accesses and @age of the new + * region are set as region size-weighted average of those of the two regions. */ struct damon_region { struct damon_addr_range ar; unsigned long sampling_addr; unsigned int nr_accesses; struct list_head list; + + unsigned int age; + unsigned int last_nr_accesses; }; /** diff --git a/mm/damon/core.c b/mm/damon/core.c index 7c547e1022af..cf3a83509bfc 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -51,6 +51,9 @@ struct damon_region *damon_new_region(unsigned long start, unsigned long end) region->nr_accesses = 0; INIT_LIST_HEAD(®ion->list); + region->age = 0; + region->last_nr_accesses = 0; + return region; } @@ -443,6 +446,7 @@ static void kdamond_reset_aggregated(struct damon_ctx *c) damon_for_each_region(r, t) { trace_damon_aggregated(t, r, damon_nr_regions(t)); + r->last_nr_accesses = r->nr_accesses; r->nr_accesses = 0; } } @@ -460,6 +464,7 @@ static void damon_merge_two_regions(struct damon_region *l, l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / (sz_l + sz_r); + l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); l->ar.end = r->ar.end; damon_destroy_region(r); } @@ -479,6 +484,11 @@ static void damon_merge_regions_of(struct damon_target *t, unsigned int thres, struct damon_region *r, *prev = NULL, *next; damon_for_each_region_safe(r, next, t) { + if (diff_of(r->nr_accesses, r->last_nr_accesses) > thres) + r->age = 0; + else + r->age++; + if (prev && prev->ar.end == r->ar.start && diff_of(prev->nr_accesses, r->nr_accesses) <= thres && sz_damon_region(prev) + sz_damon_region(r) <= sz_limit) @@ -522,6 +532,9 @@ static void damon_split_region_at(struct damon_ctx *ctx, new = damon_new_region(r->ar.start + sz_r, r->ar.end); r->ar.end = new->ar.start; + new->age = r->age; + new->last_nr_accesses = r->last_nr_accesses; + damon_insert_region(new, r, damon_next_region(r)); } -- 2.17.1