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 6982CC433DF for ; Tue, 2 Jun 2020 13:03:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B707206A4 for ; Tue, 2 Jun 2020 13:03:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="omYU7prB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727769AbgFBNDY (ORCPT ); Tue, 2 Jun 2020 09:03:24 -0400 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]:11472 "EHLO smtp-fw-33001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725919AbgFBNDV (ORCPT ); Tue, 2 Jun 2020 09:03:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1591103000; x=1622639000; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=wZuk2v8pcblyPybPvm9H+1MeNaSpGnXUM4zHP1rnXlM=; b=omYU7prB2QUecZW99ZGN18MynclDfzxoJAreMurlZOzhynGTL4LYHOSy df0CWsnq/Jv4rS/rJfImJ5TZVirqBl9a3UNDzU7VCL15f3lAG7zsQf328 Fds2/RpcrX9YNVYYnoDB+i6rj76S5mCO/wu9akYAmdeLMDcteI9Pwtccf Y=; IronPort-SDR: CaQWH/TSOZRSo+cVeNjorDuavip1b7ChoLw61iKns4p+O3jc8LNq/iXufl0WNg+Bm4N5b9Ssar cMBQ0xQozQCg== X-IronPort-AV: E=Sophos;i="5.73,464,1583193600"; d="scan'208";a="47839061" Received: from sea32-co-svc-lb4-vlan2.sea.corp.amazon.com (HELO email-inbound-relay-1a-67b371d8.us-east-1.amazon.com) ([10.47.23.34]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 02 Jun 2020 13:03:17 +0000 Received: from EX13MTAUEA002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1a-67b371d8.us-east-1.amazon.com (Postfix) with ESMTPS id 3B1F1A227C; Tue, 2 Jun 2020 13:03:05 +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 15.0.1497.2; Tue, 2 Jun 2020 13:03:05 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.161.175) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 2 Jun 2020 13:02:49 +0000 From: SeongJae Park To: CC: SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v14 02/15] mm: Introduce Data Access MONitor (DAMON) Date: Tue, 2 Jun 2020 15:01:12 +0200 Message-ID: <20200602130125.20467-3-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200602130125.20467-1-sjpark@amazon.com> References: <20200602130125.20467-1-sjpark@amazon.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.161.175] X-ClientProxiedBy: EX13D29UWC002.ant.amazon.com (10.43.162.254) To EX13D31EUA001.ant.amazon.com (10.43.165.15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: SeongJae Park This commit introduces a kernel module named DAMON. Note that this commit is implementing only the stub for the module load/unload, basic data structures, and simple manipulation functions of the structures to keep the size of commit small. The core mechanisms of DAMON will be implemented one by one by following commits. Signed-off-by: SeongJae Park Reviewed-by: Leonard Foerster --- include/linux/damon.h | 54 +++++++++++++ mm/Kconfig | 12 +++ mm/Makefile | 1 + mm/damon.c | 173 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 240 insertions(+) create mode 100644 include/linux/damon.h create mode 100644 mm/damon.c diff --git a/include/linux/damon.h b/include/linux/damon.h new file mode 100644 index 000000000000..135633334929 --- /dev/null +++ b/include/linux/damon.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * DAMON api + * + * Copyright 2019-2020 Amazon.com, Inc. or its affiliates. + * + * Author: SeongJae Park + */ + +#ifndef _DAMON_H_ +#define _DAMON_H_ + +#include +#include + +/** + * struct damon_region - Represents a monitoring target region of + * [@vm_start, @vm_end). + * + * @vm_start: Start address of the region (inclusive). + * @vm_end: End address of the region (exclusive). + * @sampling_addr: Address of the sample for the next access check. + * @nr_accesses: Access frequency of this region. + * @list: List head for siblings. + */ +struct damon_region { + unsigned long vm_start; + unsigned long vm_end; + unsigned long sampling_addr; + unsigned int nr_accesses; + struct list_head list; +}; + +/** + * struct damon_task - Represents a monitoring target task. + * @pid: Process id of the task. + * @regions_list: Head of the monitoring target regions of this task. + * @list: List head for siblings. + */ +struct damon_task { + int pid; + struct list_head regions_list; + struct list_head list; +}; + +/** + * struct damon_ctx - Represents a context for each monitoring. + * @tasks_list: Head of monitoring target tasks (&damon_task) list. + */ +struct damon_ctx { + struct list_head tasks_list; /* 'damon_task' objects */ +}; + +#endif diff --git a/mm/Kconfig b/mm/Kconfig index c1acc34c1c35..ecea0889ea35 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -867,4 +867,16 @@ config ARCH_HAS_HUGEPD config MAPPING_DIRTY_HELPERS bool +config DAMON + tristate "Data Access Monitor" + depends on MMU + help + Provides data access monitoring. + + DAMON is a kernel module that allows users to monitor the actual + memory access pattern of specific user-space processes. It aims to + be 1) accurate enough to be useful for performance-centric domains, + and 2) sufficiently light-weight so that it can be applied online. + If unsure, say N. + endmenu diff --git a/mm/Makefile b/mm/Makefile index fccd3756b25f..230e545b6e07 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -112,3 +112,4 @@ obj-$(CONFIG_MEMFD_CREATE) += memfd.o obj-$(CONFIG_MAPPING_DIRTY_HELPERS) += mapping_dirty_helpers.o obj-$(CONFIG_PTDUMP_CORE) += ptdump.o obj-$(CONFIG_PAGE_REPORTING) += page_reporting.o +obj-$(CONFIG_DAMON) += damon.o diff --git a/mm/damon.c b/mm/damon.c new file mode 100644 index 000000000000..a5a7820ef0ad --- /dev/null +++ b/mm/damon.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Data Access Monitor + * + * Copyright 2019-2020 Amazon.com, Inc. or its affiliates. + * + * Author: SeongJae Park + */ + +#define pr_fmt(fmt) "damon: " fmt + +#include +#include +#include +#include + +#define damon_get_task_struct(t) \ + (get_pid_task(find_vpid(t->pid), PIDTYPE_PID)) + +#define damon_next_region(r) \ + (container_of(r->list.next, struct damon_region, list)) + +#define damon_prev_region(r) \ + (container_of(r->list.prev, struct damon_region, list)) + +#define damon_for_each_region(r, t) \ + list_for_each_entry(r, &t->regions_list, list) + +#define damon_for_each_region_safe(r, next, t) \ + list_for_each_entry_safe(r, next, &t->regions_list, list) + +#define damon_for_each_task(t, ctx) \ + list_for_each_entry(t, &(ctx)->tasks_list, list) + +#define damon_for_each_task_safe(t, next, ctx) \ + list_for_each_entry_safe(t, next, &(ctx)->tasks_list, list) + +/* Get a random number in [l, r) */ +#define damon_rand(l, r) (l + prandom_u32() % (r - l)) + +/* + * Construct a damon_region struct + * + * Returns the pointer to the new struct if success, or NULL otherwise + */ +static struct damon_region *damon_new_region(struct damon_ctx *ctx, + unsigned long vm_start, unsigned long vm_end) +{ + struct damon_region *region; + + region = kmalloc(sizeof(*region), GFP_KERNEL); + if (!region) + return NULL; + + region->vm_start = vm_start; + region->vm_end = vm_end; + region->nr_accesses = 0; + INIT_LIST_HEAD(®ion->list); + + return region; +} + +/* + * Add a region between two other regions + */ +static inline void damon_insert_region(struct damon_region *r, + struct damon_region *prev, struct damon_region *next) +{ + __list_add(&r->list, &prev->list, &next->list); +} + +static void damon_add_region(struct damon_region *r, struct damon_task *t) +{ + list_add_tail(&r->list, &t->regions_list); +} + +static void damon_del_region(struct damon_region *r) +{ + list_del(&r->list); +} + +static void damon_free_region(struct damon_region *r) +{ + kfree(r); +} + +static void damon_destroy_region(struct damon_region *r) +{ + damon_del_region(r); + damon_free_region(r); +} + +/* + * Construct a damon_task struct + * + * Returns the pointer to the new struct if success, or NULL otherwise + */ +static struct damon_task *damon_new_task(int pid) +{ + struct damon_task *t; + + t = kmalloc(sizeof(*t), GFP_KERNEL); + if (!t) + return NULL; + + t->pid = pid; + INIT_LIST_HEAD(&t->regions_list); + + return t; +} + +static void damon_add_task(struct damon_ctx *ctx, struct damon_task *t) +{ + list_add_tail(&t->list, &ctx->tasks_list); +} + +static void damon_del_task(struct damon_task *t) +{ + list_del(&t->list); +} + +static void damon_free_task(struct damon_task *t) +{ + struct damon_region *r, *next; + + damon_for_each_region_safe(r, next, t) + damon_free_region(r); + kfree(t); +} + +static void damon_destroy_task(struct damon_task *t) +{ + damon_del_task(t); + damon_free_task(t); +} + +static unsigned int nr_damon_tasks(struct damon_ctx *ctx) +{ + struct damon_task *t; + unsigned int nr_tasks = 0; + + damon_for_each_task(t, ctx) + nr_tasks++; + + return nr_tasks; +} + +static unsigned int nr_damon_regions(struct damon_task *t) +{ + struct damon_region *r; + unsigned int nr_regions = 0; + + damon_for_each_region(r, t) + nr_regions++; + + return nr_regions; +} + +static int __init damon_init(void) +{ + return 0; +} + +static void __exit damon_exit(void) +{ +} + +module_init(damon_init); +module_exit(damon_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("SeongJae Park "); +MODULE_DESCRIPTION("DAMON: Data Access MONitor"); -- 2.17.1