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 B1905C433E0 for ; Tue, 16 Jun 2020 07:40:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 776BA20663 for ; Tue, 16 Jun 2020 07:40:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="HCtBlfE7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 776BA20663 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 225956B0027; Tue, 16 Jun 2020 03:40:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1FED76B002B; Tue, 16 Jun 2020 03:40:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 113976B002C; Tue, 16 Jun 2020 03:40:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0217.hostedemail.com [216.40.44.217]) by kanga.kvack.org (Postfix) with ESMTP id EDBD26B0027 for ; Tue, 16 Jun 2020 03:40:31 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id ABFB58248047 for ; Tue, 16 Jun 2020 07:40:31 +0000 (UTC) X-FDA: 76934277462.16.copy67_510b41726dfd Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id 7FB8D100E691F for ; Tue, 16 Jun 2020 07:40:31 +0000 (UTC) X-HE-Tag: copy67_510b41726dfd X-Filterd-Recvd-Size: 7868 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Tue, 16 Jun 2020 07:40:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1592293231; x=1623829231; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=4up0I/MNp9GTd8ElZ88SHcWEC4Z1e9krBpLWbhmn8r0=; b=HCtBlfE7+12tZ5XkisqmmNJ3G8kOxnowzR3W25DJJOPh8hoZiipwDGp8 rvlmqMFiA9HtcOAxw7bu6pwUrA+hgLOjuB64vbtqUw6L3giJNpio3xZn5 Vdgy3kAcI3zRmiqFoetIsbL9inPBSJmjeKogTZd2spUOsEaJCeLoQKqn+ k=; IronPort-SDR: pJPg3o8hj9nd5OxnmayH2SKR1LydKmnp0NOO9Wpx2EQQ+9WU1LgBA0azvWe1oMMOE/mTNr2w0J 6hmFOwyHmzmw== X-IronPort-AV: E=Sophos;i="5.73,518,1583193600"; d="scan'208";a="52568145" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-2a-d0be17ee.us-west-2.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9102.sea19.amazon.com with ESMTP; 16 Jun 2020 07:40:28 +0000 Received: from EX13MTAUEA002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2a-d0be17ee.us-west-2.amazon.com (Postfix) with ESMTPS id 68788A2683; Tue, 16 Jun 2020 07:40:25 +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; Tue, 16 Jun 2020 07:40:24 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.162.248) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 16 Jun 2020 07:39:55 +0000 From: SeongJae Park To: CC: SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC v12 2/8] mm/damon: Account age of target regions Date: Tue, 16 Jun 2020 09:38:22 +0200 Message-ID: <20200616073828.16509-3-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200616073828.16509-1-sjpark@amazon.com> References: <20200616073828.16509-1-sjpark@amazon.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.162.248] X-ClientProxiedBy: EX13D22UWC004.ant.amazon.com (10.43.162.198) To EX13D31EUA001.ant.amazon.com (10.43.165.15) X-Rspamd-Queue-Id: 7FB8D100E691F X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 as a primitive for data access pattern aware memory management optimizations. However, users who want such optimizations 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 optimizations, 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.c | 20 +++++++++++++++++--- 2 files changed, 27 insertions(+), 3 deletions(-) diff --git a/include/linux/damon.h b/include/linux/damon.h index 030f34b5176f..2e0eff17a214 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -31,12 +31,22 @@ 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.c b/mm/damon.c index 25cab8d7f21d..6a83931d4795 100644 --- a/mm/damon.c +++ b/mm/damon.c @@ -106,6 +106,9 @@ static struct damon_region *damon_new_region(struct damon_ctx *ctx, region->nr_accesses = 0; INIT_LIST_HEAD(®ion->list); + region->age = 0; + region->last_nr_accesses = 0; + return region; } @@ -806,6 +809,7 @@ static void kdamond_reset_aggregated(struct damon_ctx *c) damon_write_rbuf(c, &r->nr_accesses, sizeof(r->nr_accesses)); trace_damon_aggregated(t, r, nr); + r->last_nr_accesses = r->nr_accesses; r->nr_accesses = 0; } } @@ -819,9 +823,11 @@ static void kdamond_reset_aggregated(struct damon_ctx *c) static void damon_merge_two_regions(struct damon_region *l, struct damon_region *r) { - l->nr_accesses = (l->nr_accesses * sz_damon_region(l) + - r->nr_accesses * sz_damon_region(r)) / - (sz_damon_region(l) + sz_damon_region(r)); + unsigned long sz_l = sz_damon_region(l), sz_r = sz_damon_region(r); + + 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); } @@ -841,6 +847,11 @@ static void damon_merge_regions_of(struct damon_task *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) @@ -884,6 +895,9 @@ static void damon_split_region_at(struct damon_ctx *ctx, new = damon_new_region(ctx, 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