proc: uid: Adds accounting for the cputimes per uid.
jinqian [Wed, 11 Mar 2015 17:44:50 +0000 (10:44 -0700)]
Adds proc files /proc/uid_cputime/show_uid_stat and
/proc/uid_cputime/remove_uid_range.

show_uid_stat lists the total utime and stime for the active as well as
terminated processes for each of the uids.

Writing a range of uids to remove_uid_range will delete the accounting
for all the uids within that range.

Change-Id: I21d9210379da730b33ddc1a0ea663c8c9d2ac15b

drivers/misc/Kconfig
drivers/misc/Makefile
drivers/misc/uid_cputime.c [new file with mode: 0644]

index 3f57434..181fc59 100644 (file)
@@ -531,6 +531,12 @@ config SRAM
          the genalloc API. It is supposed to be used for small on-chip SRAM
          areas found on many SoCs.
 
+config UID_CPUTIME
+       tristate "Per-UID cpu time statistics"
+       depends on PROFILING
+       help
+         Per UID based cpu time statistics exported to /proc/uid_cputime
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
index a57666c..89435c9 100644 (file)
@@ -54,3 +54,4 @@ obj-$(CONFIG_INTEL_MEI)               += mei/
 obj-$(CONFIG_VMWARE_VMCI)      += vmw_vmci/
 obj-$(CONFIG_LATTICE_ECP3_CONFIG)      += lattice-ecp3-config.o
 obj-$(CONFIG_SRAM)             += sram.o
+obj-$(CONFIG_UID_CPUTIME) += uid_cputime.o
diff --git a/drivers/misc/uid_cputime.c b/drivers/misc/uid_cputime.c
new file mode 100644 (file)
index 0000000..cb26e3c
--- /dev/null
@@ -0,0 +1,235 @@
+/* drivers/misc/uid_cputime.c
+ *
+ * Copyright (C) 2014 - 2015 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.
+ *
+ */
+
+#include <linux/atomic.h>
+#include <linux/err.h>
+#include <linux/hashtable.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/proc_fs.h>
+#include <linux/profile.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#define UID_HASH_BITS  10
+DECLARE_HASHTABLE(hash_table, UID_HASH_BITS);
+
+static DEFINE_MUTEX(uid_lock);
+static struct proc_dir_entry *parent;
+
+struct uid_entry {
+       uid_t uid;
+       cputime_t utime;
+       cputime_t stime;
+       cputime_t active_utime;
+       cputime_t active_stime;
+       struct hlist_node hash;
+};
+
+static struct uid_entry *find_uid_entry(uid_t uid)
+{
+       struct uid_entry *uid_entry;
+       hash_for_each_possible(hash_table, uid_entry, hash, uid) {
+               if (uid_entry->uid == uid)
+                       return uid_entry;
+       }
+       return NULL;
+}
+
+static struct uid_entry *find_or_register_uid(uid_t uid)
+{
+       struct uid_entry *uid_entry;
+
+       uid_entry = find_uid_entry(uid);
+       if (uid_entry)
+               return uid_entry;
+
+       uid_entry = kzalloc(sizeof(struct uid_entry), GFP_ATOMIC);
+       if (!uid_entry)
+               return NULL;
+
+       uid_entry->uid = uid;
+
+       hash_add(hash_table, &uid_entry->hash, uid);
+
+       return uid_entry;
+}
+
+static int uid_stat_show(struct seq_file *m, void *v)
+{
+       struct uid_entry *uid_entry;
+       struct task_struct *task;
+       cputime_t utime;
+       cputime_t stime;
+       unsigned long bkt;
+
+       mutex_lock(&uid_lock);
+
+       hash_for_each(hash_table, bkt, uid_entry, hash) {
+               uid_entry->active_stime = 0;
+               uid_entry->active_utime = 0;
+       }
+
+       read_lock(&tasklist_lock);
+       for_each_process(task) {
+               uid_entry = find_or_register_uid(task_uid(task));
+               if (!uid_entry) {
+                       read_unlock(&tasklist_lock);
+                       mutex_unlock(&uid_lock);
+                       pr_err("%s: failed to find the uid_entry for uid %d\n",
+                                               __func__, task_uid(task));
+                       return -ENOMEM;
+               }
+               task_cputime_adjusted(task, &utime, &stime);
+               uid_entry->active_utime += utime;
+               uid_entry->active_stime += stime;
+       }
+       read_unlock(&tasklist_lock);
+
+       hash_for_each(hash_table, bkt, uid_entry, hash) {
+               cputime_t total_utime = uid_entry->utime +
+                                                       uid_entry->active_utime;
+               cputime_t total_stime = uid_entry->stime +
+                                                       uid_entry->active_stime;
+               seq_printf(m, "%d: %u %u\n", uid_entry->uid,
+                                               cputime_to_usecs(total_utime),
+                                               cputime_to_usecs(total_stime));
+       }
+
+       mutex_unlock(&uid_lock);
+       return 0;
+}
+
+static int uid_stat_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, uid_stat_show, PDE_DATA(inode));
+}
+
+static const struct file_operations uid_stat_fops = {
+       .open           = uid_stat_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+static int uid_remove_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, NULL, NULL);
+}
+
+static ssize_t uid_remove_write(struct file *file,
+                       const char __user *buffer, size_t count, loff_t *ppos)
+{
+       struct uid_entry *uid_entry;
+       struct hlist_node *tmp;
+       char uids[128];
+       char *start_uid, *end_uid = NULL;
+       long int uid_start = 0, uid_end = 0;
+
+       if (count >= sizeof(uids))
+               count = sizeof(uids) - 1;
+
+       if (copy_from_user(uids, buffer, count))
+               return -EFAULT;
+
+       uids[count] = '\0';
+       end_uid = uids;
+       start_uid = strsep(&end_uid, "-");
+
+       if (!start_uid || !end_uid)
+               return -EINVAL;
+
+       if (kstrtol(start_uid, 10, &uid_start) != 0 ||
+               kstrtol(end_uid, 10, &uid_end) != 0) {
+               return -EINVAL;
+       }
+
+       mutex_lock(&uid_lock);
+
+       for (; uid_start <= uid_end; uid_start++) {
+               hash_for_each_possible_safe(hash_table, uid_entry, tmp,
+                                                       hash, uid_start) {
+                       hash_del(&uid_entry->hash);
+                       kfree(uid_entry);
+               }
+       }
+
+       mutex_unlock(&uid_lock);
+       return count;
+}
+
+static const struct file_operations uid_remove_fops = {
+       .open           = uid_remove_open,
+       .release        = single_release,
+       .write          = uid_remove_write,
+};
+
+static int process_notifier(struct notifier_block *self,
+                       unsigned long cmd, void *v)
+{
+       struct task_struct *task = v;
+       struct uid_entry *uid_entry;
+       cputime_t utime, stime;
+       uid_t uid;
+
+       if (!task)
+               return NOTIFY_OK;
+
+       mutex_lock(&uid_lock);
+       uid = task_uid(task);
+       uid_entry = find_or_register_uid(uid);
+       if (!uid_entry) {
+               pr_err("%s: failed to find uid %d\n", __func__, uid);
+               goto exit;
+       }
+
+       task_cputime_adjusted(task, &utime, &stime);
+       uid_entry->utime += utime;
+       uid_entry->stime += stime;
+
+exit:
+       mutex_unlock(&uid_lock);
+       return NOTIFY_OK;
+}
+
+static struct notifier_block process_notifier_block = {
+       .notifier_call  = process_notifier,
+};
+
+static int __init proc_uid_cputime_init(void)
+{
+       hash_init(hash_table);
+
+       parent = proc_mkdir("uid_cputime", NULL);
+       if (!parent) {
+               pr_err("%s: failed to create proc entry\n", __func__);
+               return -ENOMEM;
+       }
+
+       proc_create_data("remove_uid_range", S_IWUGO, parent, &uid_remove_fops,
+                                       NULL);
+
+       proc_create_data("show_uid_stat", S_IWUGO, parent, &uid_stat_fops,
+                                       NULL);
+
+       profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block);
+
+       return 0;
+}
+
+early_initcall(proc_uid_cputime_init);