From patchwork Fri Jan 10 13:15:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 11327317 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 374B06C1 for ; Fri, 10 Jan 2020 13:16:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D97782077C for ; Fri, 10 Jan 2020 13:16:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="pNEx1rSn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D97782077C 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 DC0568E0009; Fri, 10 Jan 2020 08:16:10 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id D975B8E0001; Fri, 10 Jan 2020 08:16:10 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C10478E0009; Fri, 10 Jan 2020 08:16:10 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0045.hostedemail.com [216.40.44.45]) by kanga.kvack.org (Postfix) with ESMTP id ACBC98E0001 for ; Fri, 10 Jan 2020 08:16:10 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 62AE83ABA for ; Fri, 10 Jan 2020 13:16:10 +0000 (UTC) X-FDA: 76361772900.09.shirt75_18b620fde445d X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,prvs=271e9c931=sjpark@amazon.com,:akpm@linux-foundation.org::linux-kernel@vger.kernel.org:corbet@lwn.net:linux-doc@vger.kernel.org:mgorman@suse.de:brendanhiggins@google.com:sj38.park@gmail.com:sjpark@amazon.de,RULES_HIT:30034:30046:30051:30054:30056:30064:30070,0,RBL:207.171.184.29:@amazon.com:.lbl8.mailshell.net-62.18.0.100 66.10.201.10,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: shirt75_18b620fde445d X-Filterd-Recvd-Size: 10707 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Fri, 10 Jan 2020 13:16:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1578662170; x=1610198170; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=8zMTaLamMq4cV9+UX/hrWODp0qS6rAWD6pCOH/jGU+0=; b=pNEx1rSnU+h9ZjqzBxRXpVVffTze228UMadJIFW9obXFRgUEwtLqE99k pADtxZMZtvrF2NJ23p/af6tTdFOKhH0JvWp+fmCXh1W9tH3gI70+bG2MH bBqp5me+qAdKnWN8HH0AM8Tp8ca15nX4Si9rUXA4g6U4q4CogXd82d4j6 A=; IronPort-SDR: o6eASaivlF13dR8QnqhgoUdM0/29B+hwRuacWtdu0vYCHjjWjqoVBXXrnMze2SYGKCTjRTuR4X 85j/3ZlutbGA== X-IronPort-AV: E=Sophos;i="5.69,417,1571702400"; d="scan'208";a="17962739" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1a-807d4a99.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9102.sea19.amazon.com with ESMTP; 10 Jan 2020 13:16:05 +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-807d4a99.us-east-1.amazon.com (Postfix) with ESMTPS id 7AE70A1DB4; Fri, 10 Jan 2020 13:16:02 +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; Fri, 10 Jan 2020 13:16:01 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.161.115) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Fri, 10 Jan 2020 13:15:56 +0000 From: SeongJae Park To: CC: , , , , , , , SeongJae Park Subject: [RFC PATCH 2/5] mm/damon: Add debugfs interface Date: Fri, 10 Jan 2020 14:15:19 +0100 Message-ID: <20200110131522.29964-3-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200110131522.29964-1-sjpark@amazon.com> References: <20200110131522.29964-1-sjpark@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.161.115] X-ClientProxiedBy: EX13D10UWA001.ant.amazon.com (10.43.160.216) 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 This commit adds a debugfs interface for DAMON. DAMON exports three files, ``attrs``, ``pids``, and ``monitor_on`` under its debugfs directory, ``/damon/``. Attributes ---------- Users can read and write the ``sampling interval``, ``aggregation interval``, ``regions update interval``, min/max number of regions, and the path to ``result file`` by reading from and writing to the ``attrs`` file. For example, below commands set those values to 5 ms, 100 ms, 1,000 ms, 10, 1000, and ``/damon.data`` and check it again:: # cd /damon # echo 5000 100000 1000000 10 1000 /damon.data > attrs # cat attrs 5000 100000 1000000 10 1000 /damon.data Target PIDs ----------- Users can read and write the pids of current monitoring target processes by reading from and writing to the `pids` file. For example, below commands set processes having pids 42 and 4242 as the processes to be monitored and check it again:: # cd /damon # echo 42 4242 > pids # cat pids 42 4242 Note that setting the pids doesn't starts the monitoring. Turning On/Off -------------- You can check current status, start and stop the monitoring by reading from and writing to the ``monitor_on`` file. Writing ``on`` to the file starts DAMON to monitor the target processes with the attributes. Writing ``off`` to the file stops DAMON. DAMON also stops if every target processes is be terminated. Below example commands turn on, off, and check status of DAMON:: # cd /damon # echo on > monitor_on # echo off > monitor_on # cat monitor_on off Please note that you cannot write to the ``attrs`` and ``pids`` files while the monitoring is turned on. If you write to the files while DAMON is running, ``-EINVAL`` will be returned. Signed-off-by: SeongJae Park --- mm/damon.c | 229 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 228 insertions(+), 1 deletion(-) diff --git a/mm/damon.c b/mm/damon.c index 9a603c3f966a..0e99b4875700 100644 --- a/mm/damon.c +++ b/mm/damon.c @@ -9,6 +9,7 @@ #define pr_fmt(fmt) "damon: " fmt +#include #include #include #include @@ -1023,6 +1024,232 @@ static long damon_set_attrs(unsigned long sample_int, return 0; } +/* + * debugfs functions + */ + +static ssize_t debugfs_monitor_on_read(struct file *file, + char __user *buf, size_t count, loff_t *ppos) +{ + char monitor_on_buf[5]; + bool monitor_on; + + spin_lock(&kdamond_lock); + monitor_on = kdamond != NULL; + spin_unlock(&kdamond_lock); + + snprintf(monitor_on_buf, 5, monitor_on ? "on\n" : "off\n"); + + return simple_read_from_buffer(buf, count, ppos, monitor_on_buf, + monitor_on ? 3 : 4); +} + +static ssize_t debugfs_monitor_on_write(struct file *file, + const char __user *buf, size_t count, loff_t *ppos) +{ + ssize_t ret; + bool on = false; + char cmdbuf[5]; + + ret = simple_write_to_buffer(cmdbuf, 5, ppos, buf, count); + if (ret < 0) + return ret; + + if (sscanf(cmdbuf, "%s", cmdbuf) != 1) + return -EINVAL; + if (!strncmp(cmdbuf, "on", 5)) + on = true; + else if (!strncmp(cmdbuf, "off", 5)) + on = false; + else + return -EINVAL; + + if (damon_turn_kdamond(on)) + return -EINVAL; + + return ret; +} + +static ssize_t damon_sprint_pids(char *buf, ssize_t len) +{ + char *cursor = buf; + struct damon_task *t; + + damon_for_each_task(t) { + snprintf(cursor, len, "%lu ", t->pid); + cursor += strnlen(cursor, len); + } + if (cursor != buf) + cursor--; + snprintf(cursor, len, "\n"); + return strnlen(buf, len); +} + +static ssize_t debugfs_pids_read(struct file *file, + char __user *buf, size_t count, loff_t *ppos) +{ + ssize_t len; + char pids_buf[512]; + + len = damon_sprint_pids(pids_buf, 512); + + return simple_read_from_buffer(buf, count, ppos, pids_buf, len); +} + +/* + * Converts a string into an array of unsigned long integers + * + * Returns an array of unsigned long integers that converted, or NULL if the + * input is wrong. + */ +static unsigned long *str_to_pids(const char *str, ssize_t len, + ssize_t *nr_pids) +{ + unsigned long *pids; + unsigned long pid; + int pos = 0, parsed, ret; + + *nr_pids = 0; + pids = kmalloc_array(256, sizeof(unsigned long), GFP_KERNEL); + while (*nr_pids < 256 && pos < len) { + ret = sscanf(&str[pos], "%lu%n", &pid, &parsed); + pos += parsed; + if (ret != 1) + break; + pids[*nr_pids] = pid; + *nr_pids += 1; + } + if (*nr_pids == 0) { + kfree(pids); + pids = NULL; + } + + return pids; +} + +static ssize_t debugfs_pids_write(struct file *file, + const char __user *buf, size_t count, loff_t *ppos) +{ + ssize_t ret; + unsigned long *targets; + ssize_t nr_targets; + char pids_buf[512]; + + ret = simple_write_to_buffer(pids_buf, 512, ppos, buf, count); + if (ret < 0) + return ret; + + targets = str_to_pids(pids_buf, ret, &nr_targets); + + spin_lock(&kdamond_lock); + if (kdamond) + goto monitor_running; + + damon_set_pids(targets, nr_targets); + spin_unlock(&kdamond_lock); + kfree(targets); + + return ret; + +monitor_running: + spin_unlock(&kdamond_lock); + pr_err("%s: kdamond is running. Turn it off first.\n", __func__); + return -EINVAL; +} + +static ssize_t debugfs_attrs_read(struct file *file, + char __user *buf, size_t count, loff_t *ppos) +{ + char attrs_buf[512]; + + snprintf(attrs_buf, 512, "%lu %lu %lu %lu %lu %s\n", + sample_interval, aggr_interval, + regions_update_interval, min_nr_regions, + max_nr_regions, rfile_path); + + return simple_read_from_buffer(buf, count, ppos, attrs_buf, + strnlen(attrs_buf, 512)); +} + +static ssize_t debugfs_attrs_write(struct file *file, + const char __user *buf, size_t count, loff_t *ppos) +{ + unsigned long s, a, r, minr, maxr; + char attrs_buf[512]; + char res_file_path[LEN_RES_FILE_PATH]; + ssize_t ret; + + if (count > 512) { + pr_err("attributes stream is too large: %s\n", buf); + return -ENOMEM; + } + + ret = simple_write_to_buffer(attrs_buf, 512, ppos, buf, count); + if (ret < 0) + return ret; + + if (sscanf(attrs_buf, "%lu %lu %lu %lu %lu %s", + &s, &a, &r, &minr, &maxr, res_file_path) != 6) + return -EINVAL; + + spin_lock(&kdamond_lock); + if (kdamond) + goto monitor_running; + + damon_set_attrs(s, a, r, minr, maxr, res_file_path); + spin_unlock(&kdamond_lock); + + return ret; + +monitor_running: + spin_unlock(&kdamond_lock); + pr_err("%s: kdamond is running. Turn it off first.\n", __func__); + return -EINVAL; +} + +static const struct file_operations monitor_on_fops = { + .owner = THIS_MODULE, + .read = debugfs_monitor_on_read, + .write = debugfs_monitor_on_write, +}; + +static const struct file_operations pids_fops = { + .owner = THIS_MODULE, + .read = debugfs_pids_read, + .write = debugfs_pids_write, +}; + +static const struct file_operations attrs_fops = { + .owner = THIS_MODULE, + .read = debugfs_attrs_read, + .write = debugfs_attrs_write, +}; + +static int __init debugfs_init(void) +{ + struct dentry *debugfs_root; + const char * const file_names[] = {"attrs", "pids", "monitor_on"}; + const struct file_operations *fops[] = {&attrs_fops, &pids_fops, + &monitor_on_fops}; + int i; + + debugfs_root = debugfs_create_dir("damon", NULL); + if (!debugfs_root) { + pr_err("failed to create the debugfs dir\n"); + return -ENOMEM; + } + + for (i = 0; i < ARRAY_SIZE(file_names); i++) { + if (!debugfs_create_file(file_names[i], 0600, debugfs_root, + NULL, fops[i])) { + pr_err("failed to create %s file\n", file_names[i]); + return -ENOMEM; + } + } + + return 0; +} + static int __init damon_init(void) { pr_info("init\n"); @@ -1031,7 +1258,7 @@ static int __init damon_init(void) ktime_get_coarse_ts64(&last_aggregate_time); last_regions_update_time = last_aggregate_time; - return 0; + return debugfs_init(); } module_init(damon_init);