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 669D9C35DFB for ; Tue, 25 Feb 2020 10:25:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3371420714 for ; Tue, 25 Feb 2020 10:25:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="b4ATFEhK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730242AbgBYKZh (ORCPT ); Tue, 25 Feb 2020 05:25:37 -0500 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:45544 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729952AbgBYKZg (ORCPT ); Tue, 25 Feb 2020 05:25:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1582626335; x=1614162335; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=QOAAvZCA61DVc3DW/VsdHuEoi43TdaxmLUyV9t/JY3E=; b=b4ATFEhKx6mO2DSCHckclmqEyLO5LFPl1FftkASVrfmpQ6amuNTkZyBD H3LqJqSHBfXNQxwqJ2eQY4ftVcYq4/JFONny+n0hpU4sauc63KxKImVTD g1vCytISscP3H0J8deaC3d+uKPZ9Ah9j6+QQVP4CGJ1TnFgQhEFM6onwx A=; IronPort-SDR: z4r5X4rs+RwojLQn+u/mLVn1OxeUQy0jlgNK5r2VKwkVuuDR0hpdoyJ3c59OEyf9J247677EiK uU5T0Qn2i4pg== X-IronPort-AV: E=Sophos;i="5.70,483,1574121600"; d="scan'208";a="18080229" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1a-e34f1ddc.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 25 Feb 2020 10:25:22 +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-e34f1ddc.us-east-1.amazon.com (Postfix) with ESMTPS id A6B87A270F; Tue, 25 Feb 2020 10:25:20 +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 15.0.1236.3; Tue, 25 Feb 2020 10:25:20 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.162.53) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Tue, 25 Feb 2020 10:25:08 +0000 From: SeongJae Park To: CC: SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC v3 4/7] mm/damon/schemes: Implement a debugfs interface Date: Tue, 25 Feb 2020 11:22:57 +0100 Message-ID: <20200225102300.23895-5-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200225102300.23895-1-sjpark@amazon.com> References: <20200225102300.23895-1-sjpark@amazon.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.162.53] X-ClientProxiedBy: EX13D30UWC001.ant.amazon.com (10.43.162.128) 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 implements a debugfs interface for the data access monitoring oriented memory management schemes. It is supposed to be used by administrators and/or privileged user space programs. Users can read and update the rules using ``/damon/schemes`` file. The format is:: Signed-off-by: SeongJae Park --- mm/damon.c | 171 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 169 insertions(+), 2 deletions(-) diff --git a/mm/damon.c b/mm/damon.c index a4d6dff60b1f..b286372dbf0e 100644 --- a/mm/damon.c +++ b/mm/damon.c @@ -199,6 +199,29 @@ static void damon_destroy_task(struct damon_task *t) damon_free_task(t); } +static struct damos *damon_new_scheme( + unsigned int min_sz_region, unsigned int max_sz_region, + unsigned int min_nr_accesses, unsigned int max_nr_accesses, + unsigned int min_age_region, unsigned int max_age_region, + enum damos_action action) +{ + struct damos *ret; + + ret = kmalloc(sizeof(struct damos), GFP_KERNEL); + if (!ret) + return NULL; + ret->min_sz_region = min_sz_region; + ret->max_sz_region = max_sz_region; + ret->min_nr_accesses = min_nr_accesses; + ret->max_nr_accesses = max_nr_accesses; + ret->min_age_region = min_age_region; + ret->max_age_region = max_age_region; + ret->action = action; + INIT_LIST_HEAD(&ret->list); + + return ret; +} + static void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) { list_add_tail(&s->list, &ctx->schemes_list); @@ -1329,6 +1352,144 @@ static ssize_t debugfs_monitor_on_write(struct file *file, return ret; } +static ssize_t sprint_schemes(struct damon_ctx *c, char *buf, ssize_t len) +{ + struct damos *s; + int written = 0; + int rc; + + damon_for_each_schemes(c, s) { + rc = snprintf(&buf[written], len - written, + "%u %u %u %u %u %u %d\n", + s->min_sz_region, s->max_sz_region, + s->min_nr_accesses, s->max_nr_accesses, + s->min_age_region, s->max_age_region, + s->action); + if (!rc) + return -ENOMEM; + written += rc; + } + return written; +} + +static ssize_t debugfs_schemes_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct damon_ctx *ctx = &damon_user_ctx; + char *kbuf; + ssize_t ret; + + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + ret = sprint_schemes(ctx, kbuf, count); + if (ret < 0) + goto out; + ret = simple_read_from_buffer(buf, count, ppos, kbuf, ret); + +out: + kfree(kbuf); + return ret; +} + +static void free_schemes_arr(struct damos **schemes, ssize_t nr_schemes) +{ + ssize_t i; + + for (i = 0; i < nr_schemes; i++) + kfree(schemes[i]); + kfree(schemes); +} + +/* + * Converts a string into an array of struct damos pointers + * + * Returns an array of struct damos pointers that converted if the conversion + * success, or NULL otherwise. + */ +static struct damos **str_to_schemes(const char *str, ssize_t len, + ssize_t *nr_schemes) +{ + struct damos *scheme, **schemes; + const int max_nr_schemes = 256; + int pos = 0, parsed, ret; + unsigned int min_sz, max_sz, min_nr_a, max_nr_a, min_age, max_age; + int action; + + schemes = kmalloc_array(max_nr_schemes, sizeof(struct damos *), + GFP_KERNEL); + if (!schemes) + return NULL; + + *nr_schemes = 0; + while (pos < len && *nr_schemes < max_nr_schemes) { + ret = sscanf(&str[pos], "%u %u %u %u %u %u %d%n", + &min_sz, &max_sz, &min_nr_a, &max_nr_a, + &min_age, &max_age, &action, &parsed); + pos += parsed; + if (ret != 7) + break; + if (action >= DAMOS_ACTION_LEN) { + pr_err("wrong action %d\n", action); + goto fail; + } + + scheme = damon_new_scheme(min_sz, max_sz, min_nr_a, max_nr_a, + min_age, max_age, action); + if (!scheme) + goto fail; + + schemes[*nr_schemes] = scheme; + *nr_schemes += 1; + } + if (!*nr_schemes) + goto fail; + return schemes; +fail: + free_schemes_arr(schemes, *nr_schemes); + return NULL; +} + +static ssize_t debugfs_schemes_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct damon_ctx *ctx = &damon_user_ctx; + char *kbuf; + struct damos **schemes; + ssize_t nr_schemes = 0, ret; + + if (*ppos) + return -EINVAL; + + kbuf = kmalloc_array(count, sizeof(char), GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + ret = simple_write_to_buffer(kbuf, count, ppos, buf, count); + if (ret < 0) + goto out; + + schemes = str_to_schemes(kbuf, ret, &nr_schemes); + + spin_lock(&ctx->kdamond_lock); + if (ctx->kdamond) + goto monitor_running; + + damon_set_schemes(ctx, schemes, nr_schemes); + spin_unlock(&ctx->kdamond_lock); + goto out; + +monitor_running: + spin_unlock(&ctx->kdamond_lock); + pr_err("%s: kdamond is running. Turn it off first.\n", __func__); + ret = -EINVAL; + free_schemes_arr(schemes, nr_schemes); +out: + kfree(kbuf); + return ret; +} + static ssize_t damon_sprint_pids(struct damon_ctx *ctx, char *buf, ssize_t len) { struct damon_task *t; @@ -1559,6 +1720,12 @@ static const struct file_operations pids_fops = { .write = debugfs_pids_write, }; +static const struct file_operations schemes_fops = { + .owner = THIS_MODULE, + .read = debugfs_schemes_read, + .write = debugfs_schemes_write, +}; + static const struct file_operations record_fops = { .owner = THIS_MODULE, .read = debugfs_record_read, @@ -1575,10 +1742,10 @@ static struct dentry *debugfs_root; static int __init debugfs_init(void) { - const char * const file_names[] = {"attrs", "record", + const char * const file_names[] = {"attrs", "record", "schemes", "pids", "monitor_on"}; const struct file_operations *fops[] = {&attrs_fops, &record_fops, - &pids_fops, &monitor_on_fops}; + &schemes_fops, &pids_fops, &monitor_on_fops}; int i; debugfs_root = debugfs_create_dir("damon", NULL); -- 2.17.1