1 /* delayacct.c - per-task delay accounting
3 * Copyright (C) Shailabh Nagar, IBM Corp. 2006
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it would be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/time.h>
19 #include <linux/sysctl.h>
20 #include <linux/delayacct.h>
22 int delayacct_on __read_mostly
; /* Delay accounting turned on/off */
23 kmem_cache_t
*delayacct_cache
;
25 static int __init
delayacct_setup_enable(char *str
)
30 __setup("delayacct", delayacct_setup_enable
);
32 void delayacct_init(void)
34 delayacct_cache
= kmem_cache_create("delayacct_cache",
35 sizeof(struct task_delay_info
),
39 delayacct_tsk_init(&init_task
);
42 void __delayacct_tsk_init(struct task_struct
*tsk
)
44 tsk
->delays
= kmem_cache_zalloc(delayacct_cache
, SLAB_KERNEL
);
46 spin_lock_init(&tsk
->delays
->lock
);
49 void __delayacct_tsk_exit(struct task_struct
*tsk
)
51 kmem_cache_free(delayacct_cache
, tsk
->delays
);
56 * Start accounting for a delay statistic using
57 * its starting timestamp (@start)
60 static inline void delayacct_start(struct timespec
*start
)
62 do_posix_clock_monotonic_gettime(start
);
66 * Finish delay accounting for a statistic using
67 * its timestamps (@start, @end), accumalator (@total) and @count
70 static void delayacct_end(struct timespec
*start
, struct timespec
*end
,
71 u64
*total
, u32
*count
)
76 do_posix_clock_monotonic_gettime(end
);
77 ts
= timespec_sub(*end
, *start
);
78 ns
= timespec_to_ns(&ts
);
82 spin_lock(¤t
->delays
->lock
);
85 spin_unlock(¤t
->delays
->lock
);