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Diffstat (limited to 'net/activity_stats.c')
-rw-r--r-- | net/activity_stats.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/net/activity_stats.c b/net/activity_stats.c new file mode 100644 index 000000000000..4609ce2043eb --- /dev/null +++ b/net/activity_stats.c @@ -0,0 +1,119 @@ +/* net/activity_stats.c + * + * Copyright (C) 2010 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Author: Mike Chan (mike@android.com) + */ + +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/suspend.h> +#include <net/net_namespace.h> + +/* + * Track transmission rates in buckets (power of 2). + * 1,2,4,8...512 seconds. + * + * Buckets represent the count of network transmissions at least + * N seconds apart, where N is 1 << bucket index. + */ +#define BUCKET_MAX 10 + +/* Track network activity frequency */ +static unsigned long activity_stats[BUCKET_MAX]; +static ktime_t last_transmit; +static ktime_t suspend_time; +static DEFINE_SPINLOCK(activity_lock); + +void activity_stats_update(void) +{ + int i; + unsigned long flags; + ktime_t now; + s64 delta; + + spin_lock_irqsave(&activity_lock, flags); + now = ktime_get(); + delta = ktime_to_ns(ktime_sub(now, last_transmit)); + + for (i = BUCKET_MAX - 1; i >= 0; i--) { + /* + * Check if the time delta between network activity is within the + * minimum bucket range. + */ + if (delta < (1000000000ULL << i)) + continue; + + activity_stats[i]++; + last_transmit = now; + break; + } + spin_unlock_irqrestore(&activity_lock, flags); +} + +static int activity_stats_show(struct seq_file *m, void *v) +{ + int i; + int ret; + + seq_printf(m, "Min Bucket(sec) Count\n"); + + for (i = 0; i < BUCKET_MAX; i++) { + ret = seq_printf(m, "%15d %lu\n", 1 << i, activity_stats[i]); + if (ret) + return ret; + } + + return 0; +} + +static int activity_stats_notifier(struct notifier_block *nb, + unsigned long event, void *dummy) +{ + switch (event) { + case PM_SUSPEND_PREPARE: + suspend_time = ktime_get_real(); + break; + + case PM_POST_SUSPEND: + suspend_time = ktime_sub(ktime_get_real(), suspend_time); + last_transmit = ktime_sub(last_transmit, suspend_time); + } + + return 0; +} + +static int activity_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, activity_stats_show, PDE_DATA(inode)); +} + +static const struct file_operations activity_stats_fops = { + .open = activity_stats_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static struct notifier_block activity_stats_notifier_block = { + .notifier_call = activity_stats_notifier, +}; + +static int __init activity_stats_init(void) +{ + proc_create("activity", S_IRUGO, + init_net.proc_net_stat, &activity_stats_fops); + return register_pm_notifier(&activity_stats_notifier_block); +} + +subsys_initcall(activity_stats_init); + |