From patchwork Mon Oct 5 10:55:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 11816461 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 0B6F992C for ; Mon, 5 Oct 2020 11:00:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A86B62078E for ; Mon, 5 Oct 2020 11:00:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="vXmZyEO9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A86B62078E 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 E94B36B0070; Mon, 5 Oct 2020 07:00:14 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id E43126B0074; Mon, 5 Oct 2020 07:00:14 -0400 (EDT) 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 D0A736B0075; Mon, 5 Oct 2020 07:00:14 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0178.hostedemail.com [216.40.44.178]) by kanga.kvack.org (Postfix) with ESMTP id A37BC6B0070 for ; Mon, 5 Oct 2020 07:00:14 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 36D51824999B for ; Mon, 5 Oct 2020 11:00:14 +0000 (UTC) X-FDA: 77337577548.30.laugh66_2e084f7271bd Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id EF8A2180B3C85 for ; Mon, 5 Oct 2020 11:00:13 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,prvs=5409d9be5=sjpark@amazon.com,,RULES_HIT:30003:30012:30029:30051:30054:30064:30070,0,RBL:207.171.190.10:@amazon.com:.lbl8.mailshell.net-62.18.0.100 66.10.201.10;04yg9w7xtu6kkw4dawzaq1k4eg1iaopbmxfyfq1bbes13aimcqwrq3t4p3h1ti5.bshp648hxn3mff13rcrffsw4gpr39yg3jtb9qegqjodmobug34goyr5oiuw68pu.k-lbl8.mailshell.net-223.238.255.100,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: laugh66_2e084f7271bd X-Filterd-Recvd-Size: 10764 Received: from smtp-fw-33001.amazon.com (smtp-fw-33001.amazon.com [207.171.190.10]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Mon, 5 Oct 2020 11:00:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1601895614; x=1633431614; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=DERTYCN9LGz8Thwa5CF835CXM4gb7wb691pVE0xmJk8=; b=vXmZyEO9ZkR0jC0KynUb8+Efo4jsxvQqSAhXATonFuO7xb7+kS+34In6 eN28UEGHLgsyk8XWAbiK76Foq85uj0FFL8hB54wTzFNOg6BV3fNf70RKd sWuS45UovZ+gtis1X3ol74efxN69IFEPAzS3I3EPuV5q9Ou8Dc4olGJl1 4=; X-IronPort-AV: E=Sophos;i="5.77,338,1596499200"; d="scan'208";a="80358370" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1e-a70de69e.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 05 Oct 2020 11:00:10 +0000 Received: from EX13D31EUA001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-1e-a70de69e.us-east-1.amazon.com (Postfix) with ESMTPS id DE3B1A072C; Mon, 5 Oct 2020 10:59:57 +0000 (UTC) Received: from u3f2cd687b01c55.ant.amazon.com (10.43.160.146) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 5 Oct 2020 10:59:40 +0000 From: SeongJae Park To: CC: SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v21 13/18] mm/damon/dbgfs: Support multiple contexts Date: Mon, 5 Oct 2020 12:55:17 +0200 Message-ID: <20201005105522.23841-14-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201005105522.23841-1-sjpark@amazon.com> References: <20201005105522.23841-1-sjpark@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.146] X-ClientProxiedBy: EX13d09UWC002.ant.amazon.com (10.43.162.102) 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 In some use cases, users would want to run multiple monitoring context. For example, if a user wants a high precision monitoring and dedicating multiple CPUs for the job is ok, because DAMON creates one monitoring thread per one context, the user can split the monitoring target regions into multiple small regions and create one context for each region. Or, someone might want to simultaneously monitor different address spaces, e.g., both virtual address space and physical address space. The DAMON's API allows such usage, but 'damon-dbgfs' does not. Therefore, only kernel space DAMON users can do multiple contexts monitoring. This commit allows the user space DAMON users to use multiple contexts monitoring by introducing two new 'damon-dbgfs' debugfs files, 'mk_context' and 'rm_context'. Users can create a new monitoring context by writing the desired name of the new context to 'mk_context'. Then, a new directory with the name and having the files for setting of the context ('attrs', 'target_ids' and 'record') will be created under the debugfs directory. Writing the name of the context to remove to 'rm_context' will remove the related context and directory. Signed-off-by: SeongJae Park --- mm/damon/dbgfs.c | 214 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 211 insertions(+), 3 deletions(-) diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index a0956618ec2d..908fa395bdfb 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -434,7 +434,7 @@ static int dbgfs_fill_ctx_dir(struct dentry *dir, struct damon_ctx *ctx) const char * const file_names[] = {"attrs", "record", "target_ids", "kdamond_pid"}; const struct file_operations *fops[] = {&attrs_fops, &record_fops, - &target_ids_fops}, &kdamond_pid_fops; + &target_ids_fops, &kdamond_pid_fops}; int i; for (i = 0; i < ARRAY_SIZE(file_names); i++) { @@ -506,6 +506,13 @@ static void dbgfs_write_record_header(struct damon_ctx *ctx) dbgfs_write_rbuf(ctx, &recfmt_ver, sizeof(recfmt_ver)); } +static void dbgfs_free_recorder(struct dbgfs_recorder *recorder) +{ + kfree(recorder->rbuf); + kfree(recorder->rfile_path); + kfree(recorder); +} + static unsigned int nr_damon_targets(struct damon_ctx *ctx) { struct damon_target *t; @@ -599,6 +606,195 @@ static struct damon_ctx *dbgfs_new_ctx(void) return ctx; } +static void dbgfs_destroy_ctx(struct damon_ctx *ctx) +{ + dbgfs_free_recorder(ctx->callback.private); + damon_destroy_ctx(ctx); +} + +/* + * Make a context of @name and create a debugfs directory for it. + * + * This function should be called while holding damon_dbgfs_lock. + * + * Returns 0 on success, negative error code otherwise. + */ +static int dbgfs_mk_context(char *name) +{ + struct dentry *root, **new_dirs, *new_dir; + struct damon_ctx **new_ctxs, *new_ctx; + int err; + + if (damon_nr_running_ctxs()) + return -EBUSY; + + new_ctxs = krealloc(dbgfs_ctxs, sizeof(*dbgfs_ctxs) * + (dbgfs_nr_ctxs + 1), GFP_KERNEL); + if (!new_ctxs) + return -ENOMEM; + + new_dirs = krealloc(dbgfs_dirs, sizeof(*dbgfs_dirs) * + (dbgfs_nr_ctxs + 1), GFP_KERNEL); + if (!new_dirs) { + kfree(new_ctxs); + return -ENOMEM; + } + + dbgfs_ctxs = new_ctxs; + dbgfs_dirs = new_dirs; + + root = dbgfs_dirs[0]; + if (!root) + return -ENOENT; + + new_dir = debugfs_create_dir(name, root); + if (IS_ERR(new_dir)) + return PTR_ERR(new_dir); + dbgfs_dirs[dbgfs_nr_ctxs] = new_dir; + + new_ctx = dbgfs_new_ctx(); + if (!new_ctx) { + debugfs_remove(new_dir); + dbgfs_dirs[dbgfs_nr_ctxs] = NULL; + return -ENOMEM; + } + dbgfs_ctxs[dbgfs_nr_ctxs] = new_ctx; + + err = dbgfs_fill_ctx_dir(dbgfs_dirs[dbgfs_nr_ctxs], + dbgfs_ctxs[dbgfs_nr_ctxs]); + if (err) + return err; + + dbgfs_nr_ctxs++; + return 0; +} + +static ssize_t dbgfs_mk_context_write(struct file *file, + const char __user *buf, size_t count, loff_t *ppos) +{ + char *kbuf; + char *ctx_name; + ssize_t ret = count; + int err; + + kbuf = user_input_str(buf, count, ppos); + if (IS_ERR(kbuf)) + return PTR_ERR(kbuf); + ctx_name = kmalloc(count + 1, GFP_KERNEL); + if (!ctx_name) { + kfree(kbuf); + return -ENOMEM; + } + + /* Trim white space */ + if (sscanf(kbuf, "%s", ctx_name) != 1) { + ret = -EINVAL; + goto out; + } + + mutex_lock(&damon_dbgfs_lock); + err = dbgfs_mk_context(ctx_name); + if (err) + ret = err; + mutex_unlock(&damon_dbgfs_lock); + +out: + kfree(kbuf); + kfree(ctx_name); + return ret; +} + +/* + * Remove a context of @name and its debugfs directory. + * + * This function should be called while holding damon_dbgfs_lock. + * + * Return 0 on success, negative error code otherwise. + */ +static int dbgfs_rm_context(char *name) +{ + struct dentry *root, *dir, **new_dirs; + struct damon_ctx **new_ctxs; + int i, j; + + if (damon_nr_running_ctxs()) + return -EBUSY; + + root = dbgfs_dirs[0]; + if (!root) + return -ENOENT; + + dir = debugfs_lookup(name, root); + if (!dir) + return -ENOENT; + + new_dirs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_dirs), + GFP_KERNEL); + if (!new_dirs) + return -ENOMEM; + + new_ctxs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_ctxs), + GFP_KERNEL); + if (!new_ctxs) { + kfree(new_dirs); + return -ENOMEM; + } + + for (i = 0, j = 0; i < dbgfs_nr_ctxs; i++) { + if (dbgfs_dirs[i] == dir) { + debugfs_remove(dbgfs_dirs[i]); + dbgfs_destroy_ctx(dbgfs_ctxs[i]); + continue; + } + new_dirs[j] = dbgfs_dirs[i]; + new_ctxs[j++] = dbgfs_ctxs[i]; + } + + kfree(dbgfs_dirs); + kfree(dbgfs_ctxs); + + dbgfs_dirs = new_dirs; + dbgfs_ctxs = new_ctxs; + dbgfs_nr_ctxs--; + + return 0; +} + +static ssize_t dbgfs_rm_context_write(struct file *file, + const char __user *buf, size_t count, loff_t *ppos) +{ + char *kbuf; + ssize_t ret = count; + int err; + char *ctx_name; + + kbuf = user_input_str(buf, count, ppos); + if (IS_ERR(kbuf)) + return PTR_ERR(kbuf); + ctx_name = kmalloc(count + 1, GFP_KERNEL); + if (!ctx_name) { + kfree(kbuf); + return -ENOMEM; + } + + /* Trim white space */ + if (sscanf(kbuf, "%s", ctx_name) != 1) { + ret = -EINVAL; + goto out; + } + + mutex_lock(&damon_dbgfs_lock); + err = dbgfs_rm_context(ctx_name); + if (err) + ret = err; + mutex_unlock(&damon_dbgfs_lock); + +out: + kfree(kbuf); + kfree(ctx_name); + return ret; +} + static ssize_t dbgfs_monitor_on_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { @@ -651,6 +847,16 @@ static ssize_t dbgfs_monitor_on_write(struct file *file, return ret; } +static const struct file_operations mk_contexts_fops = { + .owner = THIS_MODULE, + .write = dbgfs_mk_context_write, +}; + +static const struct file_operations rm_contexts_fops = { + .owner = THIS_MODULE, + .write = dbgfs_rm_context_write, +}; + static const struct file_operations monitor_on_fops = { .owner = THIS_MODULE, .read = dbgfs_monitor_on_read, @@ -660,8 +866,10 @@ static const struct file_operations monitor_on_fops = { static int __init __damon_dbgfs_init(void) { struct dentry *dbgfs_root; - const char * const file_names[] = {"monitor_on"}; - const struct file_operations *fops[] = {&monitor_on_fops}; + const char * const file_names[] = {"mk_contexts", "rm_contexts", + "monitor_on"}; + const struct file_operations *fops[] = {&mk_contexts_fops, + &rm_contexts_fops, &monitor_on_fops}; int i; dbgfs_root = debugfs_create_dir("damon", NULL);