ALSA: hda - Make jack-plug notification selectable
[linux-2.6/mini2440.git] / kernel / delayacct.c
blobabb6e17505e289f7a4db6757d48995030bddf477
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 = 1; /* Delay accounting turned on/off */
23 struct kmem_cache *delayacct_cache;
25 static int __init delayacct_setup_disable(char *str)
27 delayacct_on = 0;
28 return 1;
30 __setup("nodelayacct", delayacct_setup_disable);
32 void delayacct_init(void)
34 delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC);
35 delayacct_tsk_init(&init_task);
38 void __delayacct_tsk_init(struct task_struct *tsk)
40 tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL);
41 if (tsk->delays)
42 spin_lock_init(&tsk->delays->lock);
46 * Start accounting for a delay statistic using
47 * its starting timestamp (@start)
50 static inline void delayacct_start(struct timespec *start)
52 do_posix_clock_monotonic_gettime(start);
56 * Finish delay accounting for a statistic using
57 * its timestamps (@start, @end), accumalator (@total) and @count
60 static void delayacct_end(struct timespec *start, struct timespec *end,
61 u64 *total, u32 *count)
63 struct timespec ts;
64 s64 ns;
65 unsigned long flags;
67 do_posix_clock_monotonic_gettime(end);
68 ts = timespec_sub(*end, *start);
69 ns = timespec_to_ns(&ts);
70 if (ns < 0)
71 return;
73 spin_lock_irqsave(&current->delays->lock, flags);
74 *total += ns;
75 (*count)++;
76 spin_unlock_irqrestore(&current->delays->lock, flags);
79 void __delayacct_blkio_start(void)
81 delayacct_start(&current->delays->blkio_start);
84 void __delayacct_blkio_end(void)
86 if (current->delays->flags & DELAYACCT_PF_SWAPIN)
87 /* Swapin block I/O */
88 delayacct_end(&current->delays->blkio_start,
89 &current->delays->blkio_end,
90 &current->delays->swapin_delay,
91 &current->delays->swapin_count);
92 else /* Other block I/O */
93 delayacct_end(&current->delays->blkio_start,
94 &current->delays->blkio_end,
95 &current->delays->blkio_delay,
96 &current->delays->blkio_count);
99 int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
101 s64 tmp;
102 unsigned long t1;
103 unsigned long long t2, t3;
104 unsigned long flags;
105 struct timespec ts;
107 /* Though tsk->delays accessed later, early exit avoids
108 * unnecessary returning of other data
110 if (!tsk->delays)
111 goto done;
113 tmp = (s64)d->cpu_run_real_total;
114 cputime_to_timespec(tsk->utime + tsk->stime, &ts);
115 tmp += timespec_to_ns(&ts);
116 d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
118 tmp = (s64)d->cpu_scaled_run_real_total;
119 cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts);
120 tmp += timespec_to_ns(&ts);
121 d->cpu_scaled_run_real_total =
122 (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
125 * No locking available for sched_info (and too expensive to add one)
126 * Mitigate by taking snapshot of values
128 t1 = tsk->sched_info.pcount;
129 t2 = tsk->sched_info.run_delay;
130 t3 = tsk->se.sum_exec_runtime;
132 d->cpu_count += t1;
134 tmp = (s64)d->cpu_delay_total + t2;
135 d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp;
137 tmp = (s64)d->cpu_run_virtual_total + t3;
138 d->cpu_run_virtual_total =
139 (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp;
141 /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
143 spin_lock_irqsave(&tsk->delays->lock, flags);
144 tmp = d->blkio_delay_total + tsk->delays->blkio_delay;
145 d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp;
146 tmp = d->swapin_delay_total + tsk->delays->swapin_delay;
147 d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp;
148 tmp = d->freepages_delay_total + tsk->delays->freepages_delay;
149 d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
150 d->blkio_count += tsk->delays->blkio_count;
151 d->swapin_count += tsk->delays->swapin_count;
152 d->freepages_count += tsk->delays->freepages_count;
153 spin_unlock_irqrestore(&tsk->delays->lock, flags);
155 done:
156 return 0;
159 __u64 __delayacct_blkio_ticks(struct task_struct *tsk)
161 __u64 ret;
162 unsigned long flags;
164 spin_lock_irqsave(&tsk->delays->lock, flags);
165 ret = nsec_to_clock_t(tsk->delays->blkio_delay +
166 tsk->delays->swapin_delay);
167 spin_unlock_irqrestore(&tsk->delays->lock, flags);
168 return ret;
171 void __delayacct_freepages_start(void)
173 delayacct_start(&current->delays->freepages_start);
176 void __delayacct_freepages_end(void)
178 delayacct_end(&current->delays->freepages_start,
179 &current->delays->freepages_end,
180 &current->delays->freepages_delay,
181 &current->delays->freepages_count);