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IronPort-SDR: JihEk3tq+L/k3x8K4/LXkgaonWgVC1AK9wdZnbsingnf+fkoKZSA+hRyss0GeRA7I4Ik+FihAp zHW/JgQPkQNA== X-IronPort-AV: E=Sophos;i="5.73,467,1583193600"; d="scan'208";a="49422701" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1e-c7c08562.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9102.sea19.amazon.com with ESMTP; 03 Jun 2020 07:15:25 +0000 Received: from EX13MTAUEA002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1e-c7c08562.us-east-1.amazon.com (Postfix) with ESMTPS id EB6DF24252F; Wed, 3 Jun 2020 07:15:22 +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; Wed, 3 Jun 2020 07:15:22 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.160.26) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 3 Jun 2020 07:15:06 +0000 From: SeongJae Park To: CC: SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC v10 4/8] mm/damon/schemes: Implement a debugfs interface Date: Wed, 3 Jun 2020 09:11:34 +0200 Message-ID: <20200603071138.8152-5-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200603071138.8152-1-sjpark@amazon.com> References: <20200603071138.8152-1-sjpark@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.26] X-ClientProxiedBy: EX13D10UWB003.ant.amazon.com (10.43.161.106) To EX13D31EUA001.ant.amazon.com (10.43.165.15) X-Rspamd-Queue-Id: 1A46A80081D1 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 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 | 176 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 174 insertions(+), 2 deletions(-) diff --git a/mm/damon.c b/mm/damon.c index ffb755a14447..909599e6e5bc 100644 --- a/mm/damon.c +++ b/mm/damon.c @@ -173,6 +173,29 @@ 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 *scheme; + + scheme = kmalloc(sizeof(*scheme), GFP_KERNEL); + if (!scheme) + return NULL; + scheme->min_sz_region = min_sz_region; + scheme->max_sz_region = max_sz_region; + scheme->min_nr_accesses = min_nr_accesses; + scheme->max_nr_accesses = max_nr_accesses; + scheme->min_age_region = min_age_region; + scheme->max_age_region = max_age_region; + scheme->action = action; + INIT_LIST_HEAD(&scheme->list); + + return scheme; +} + static void damon_add_scheme(struct damon_ctx *ctx, struct damos *s) { list_add_tail(&s->list, &ctx->schemes_list); @@ -1353,6 +1376,149 @@ 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_scheme(s, c) { + 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 len; + + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + mutex_lock(&ctx->kdamond_lock); + len = sprint_schemes(ctx, kbuf, count); + mutex_unlock(&ctx->kdamond_lock); + if (len < 0) + goto out; + len = simple_read_from_buffer(buf, count, ppos, kbuf, len); + +out: + kfree(kbuf); + return len; +} + +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; + unsigned int action; + + schemes = kmalloc_array(max_nr_schemes, sizeof(scheme), + 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 %u%n", + &min_sz, &max_sz, &min_nr_a, &max_nr_a, + &min_age, &max_age, &action, &parsed); + if (ret != 7) + break; + if (action >= DAMOS_ACTION_LEN) { + pr_err("wrong action %d\n", action); + goto fail; + } + + pos += parsed; + 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; + int err; + + if (*ppos) + return -EINVAL; + + kbuf = kmalloc(count, 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); + + mutex_lock(&ctx->kdamond_lock); + if (ctx->kdamond) { + ret = -EBUSY; + goto unlock_out; + } + + err = damon_set_schemes(ctx, schemes, nr_schemes); + if (err) + ret = err; + else + nr_schemes = 0; +unlock_out: + mutex_unlock(&ctx->kdamond_lock); + 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; @@ -1584,6 +1750,12 @@ 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, @@ -1600,10 +1772,10 @@ static struct dentry *debugfs_root; static int __init damon_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);