Print this page
5042 stop using deprecated atomic functions
| Split |
Close |
| Expand all |
| Collapse all |
--- old/usr/src/uts/common/os/dtrace_subr.c
+++ new/usr/src/uts/common/os/dtrace_subr.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21
22 22 /*
23 23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
24 24 * Use is subject to license terms.
25 25 */
26 26
27 27 #include <sys/dtrace.h>
28 28 #include <sys/cmn_err.h>
29 29 #include <sys/tnf.h>
30 30 #include <sys/atomic.h>
31 31 #include <sys/prsystm.h>
32 32 #include <sys/modctl.h>
33 33 #include <sys/aio_impl.h>
34 34
35 35 #ifdef __sparc
36 36 #include <sys/privregs.h>
37 37 #endif
38 38
39 39 void (*dtrace_cpu_init)(processorid_t);
40 40 void (*dtrace_modload)(struct modctl *);
41 41 void (*dtrace_modunload)(struct modctl *);
42 42 void (*dtrace_helpers_cleanup)(void);
43 43 void (*dtrace_helpers_fork)(proc_t *, proc_t *);
44 44 void (*dtrace_cpustart_init)(void);
45 45 void (*dtrace_cpustart_fini)(void);
46 46 void (*dtrace_cpc_fire)(uint64_t);
47 47 void (*dtrace_closef)(void);
48 48
49 49 void (*dtrace_debugger_init)(void);
50 50 void (*dtrace_debugger_fini)(void);
51 51
52 52 dtrace_vtime_state_t dtrace_vtime_active = 0;
53 53 dtrace_cacheid_t dtrace_predcache_id = DTRACE_CACHEIDNONE + 1;
54 54
55 55 /*
56 56 * dtrace_cpc_in_use usage statement: this global variable is used by the cpc
57 57 * hardware overflow interrupt handler and the kernel cpc framework to check
58 58 * whether or not the DTrace cpc provider is currently in use. The variable is
59 59 * set before counters are enabled with the first enabling and cleared when
60 60 * the last enabling is disabled. Its value at any given time indicates the
61 61 * number of active dcpc based enablings. The global 'kcpc_cpuctx_lock' rwlock
62 62 * is held during initial setting to protect races between kcpc_open() and the
63 63 * first enabling. The locking provided by the DTrace subsystem, the kernel
64 64 * cpc framework and the cpu management framework protect consumers from race
65 65 * conditions on enabling and disabling probes.
66 66 */
67 67 uint32_t dtrace_cpc_in_use = 0;
68 68
69 69 typedef struct dtrace_hrestime {
70 70 lock_t dthr_lock; /* lock for this element */
71 71 timestruc_t dthr_hrestime; /* hrestime value */
72 72 int64_t dthr_adj; /* hrestime_adj value */
73 73 hrtime_t dthr_hrtime; /* hrtime value */
74 74 } dtrace_hrestime_t;
75 75
76 76 static dtrace_hrestime_t dtrace_hrestime[2];
77 77
78 78 /*
79 79 * Making available adjustable high-resolution time in DTrace is regrettably
80 80 * more complicated than one might think it should be. The problem is that
81 81 * the variables related to adjusted high-resolution time (hrestime,
82 82 * hrestime_adj and friends) are adjusted under hres_lock -- and this lock may
83 83 * be held when we enter probe context. One might think that we could address
84 84 * this by having a single snapshot copy that is stored under a different lock
85 85 * from hres_tick(), using the snapshot iff hres_lock is locked in probe
86 86 * context. Unfortunately, this too won't work: because hres_lock is grabbed
87 87 * in more than just hres_tick() context, we could enter probe context
88 88 * concurrently on two different CPUs with both locks (hres_lock and the
89 89 * snapshot lock) held. As this implies, the fundamental problem is that we
90 90 * need to have access to a snapshot of these variables that we _know_ will
91 91 * not be locked in probe context. To effect this, we have two snapshots
92 92 * protected by two different locks, and we mandate that these snapshots are
93 93 * recorded in succession by a single thread calling dtrace_hres_tick(). (We
94 94 * assure this by calling it out of the same CY_HIGH_LEVEL cyclic that calls
95 95 * hres_tick().) A single thread can't be in two places at once: one of the
96 96 * snapshot locks is guaranteed to be unheld at all times. The
97 97 * dtrace_gethrestime() algorithm is thus to check first one snapshot and then
98 98 * the other to find the unlocked snapshot.
99 99 */
100 100 void
101 101 dtrace_hres_tick(void)
102 102 {
103 103 int i;
104 104 ushort_t spl;
105 105
106 106 for (i = 0; i < 2; i++) {
107 107 dtrace_hrestime_t tmp;
108 108
109 109 spl = hr_clock_lock();
110 110 tmp.dthr_hrestime = hrestime;
111 111 tmp.dthr_adj = hrestime_adj;
112 112 tmp.dthr_hrtime = dtrace_gethrtime();
113 113 hr_clock_unlock(spl);
114 114
115 115 lock_set(&dtrace_hrestime[i].dthr_lock);
116 116 dtrace_hrestime[i].dthr_hrestime = tmp.dthr_hrestime;
117 117 dtrace_hrestime[i].dthr_adj = tmp.dthr_adj;
118 118 dtrace_hrestime[i].dthr_hrtime = tmp.dthr_hrtime;
119 119 dtrace_membar_producer();
120 120
121 121 /*
122 122 * To allow for lock-free examination of this lock, we use
123 123 * the same trick that is used hres_lock; for more details,
124 124 * see the description of this technique in sun4u/sys/clock.h.
125 125 */
126 126 dtrace_hrestime[i].dthr_lock++;
127 127 }
128 128 }
129 129
130 130 hrtime_t
131 131 dtrace_gethrestime(void)
132 132 {
133 133 dtrace_hrestime_t snap;
134 134 hrtime_t now;
135 135 int i = 0, adj, nslt;
136 136
137 137 for (;;) {
138 138 snap.dthr_lock = dtrace_hrestime[i].dthr_lock;
139 139 dtrace_membar_consumer();
140 140 snap.dthr_hrestime = dtrace_hrestime[i].dthr_hrestime;
141 141 snap.dthr_hrtime = dtrace_hrestime[i].dthr_hrtime;
142 142 snap.dthr_adj = dtrace_hrestime[i].dthr_adj;
143 143 dtrace_membar_consumer();
144 144
145 145 if ((snap.dthr_lock & ~1) == dtrace_hrestime[i].dthr_lock)
146 146 break;
147 147
148 148 /*
149 149 * If we're here, the lock was either locked, or it
150 150 * transitioned while we were taking the snapshot. Either
151 151 * way, we're going to try the other dtrace_hrestime element;
152 152 * we know that it isn't possible for both to be locked
153 153 * simultaneously, so we will ultimately get a good snapshot.
154 154 */
155 155 i ^= 1;
156 156 }
157 157
158 158 /*
159 159 * We have a good snapshot. Now perform any necessary adjustments.
160 160 */
161 161 nslt = dtrace_gethrtime() - snap.dthr_hrtime;
162 162 ASSERT(nslt >= 0);
163 163
164 164 now = ((hrtime_t)snap.dthr_hrestime.tv_sec * (hrtime_t)NANOSEC) +
165 165 snap.dthr_hrestime.tv_nsec;
166 166
167 167 if (snap.dthr_adj != 0) {
168 168 if (snap.dthr_adj > 0) {
169 169 adj = (nslt >> adj_shift);
170 170 if (adj > snap.dthr_adj)
171 171 adj = (int)snap.dthr_adj;
172 172 } else {
173 173 adj = -(nslt >> adj_shift);
174 174 if (adj < snap.dthr_adj)
175 175 adj = (int)snap.dthr_adj;
176 176 }
177 177 now += adj;
178 178 }
179 179
180 180 return (now);
181 181 }
182 182
183 183 void
184 184 dtrace_vtime_enable(void)
185 185 {
186 186 dtrace_vtime_state_t state, nstate;
187 187
188 188 do {
189 189 state = dtrace_vtime_active;
190 190
191 191 switch (state) {
192 192 case DTRACE_VTIME_INACTIVE:
193 193 nstate = DTRACE_VTIME_ACTIVE;
194 194 break;
195 195
|
↓ open down ↓ |
195 lines elided |
↑ open up ↑ |
196 196 case DTRACE_VTIME_INACTIVE_TNF:
197 197 nstate = DTRACE_VTIME_ACTIVE_TNF;
198 198 break;
199 199
200 200 case DTRACE_VTIME_ACTIVE:
201 201 case DTRACE_VTIME_ACTIVE_TNF:
202 202 panic("DTrace virtual time already enabled");
203 203 /*NOTREACHED*/
204 204 }
205 205
206 - } while (cas32((uint32_t *)&dtrace_vtime_active,
206 + } while (atomic_cas_32((uint32_t *)&dtrace_vtime_active,
207 207 state, nstate) != state);
208 208 }
209 209
210 210 void
211 211 dtrace_vtime_disable(void)
212 212 {
213 213 dtrace_vtime_state_t state, nstate;
214 214
215 215 do {
216 216 state = dtrace_vtime_active;
217 217
218 218 switch (state) {
219 219 case DTRACE_VTIME_ACTIVE:
220 220 nstate = DTRACE_VTIME_INACTIVE;
221 221 break;
222 222
|
↓ open down ↓ |
6 lines elided |
↑ open up ↑ |
223 223 case DTRACE_VTIME_ACTIVE_TNF:
224 224 nstate = DTRACE_VTIME_INACTIVE_TNF;
225 225 break;
226 226
227 227 case DTRACE_VTIME_INACTIVE:
228 228 case DTRACE_VTIME_INACTIVE_TNF:
229 229 panic("DTrace virtual time already disabled");
230 230 /*NOTREACHED*/
231 231 }
232 232
233 - } while (cas32((uint32_t *)&dtrace_vtime_active,
233 + } while (atomic_cas_32((uint32_t *)&dtrace_vtime_active,
234 234 state, nstate) != state);
235 235 }
236 236
237 237 void
238 238 dtrace_vtime_enable_tnf(void)
239 239 {
240 240 dtrace_vtime_state_t state, nstate;
241 241
242 242 do {
243 243 state = dtrace_vtime_active;
244 244
245 245 switch (state) {
246 246 case DTRACE_VTIME_ACTIVE:
247 247 nstate = DTRACE_VTIME_ACTIVE_TNF;
248 248 break;
249 249
|
↓ open down ↓ |
6 lines elided |
↑ open up ↑ |
250 250 case DTRACE_VTIME_INACTIVE:
251 251 nstate = DTRACE_VTIME_INACTIVE_TNF;
252 252 break;
253 253
254 254 case DTRACE_VTIME_ACTIVE_TNF:
255 255 case DTRACE_VTIME_INACTIVE_TNF:
256 256 panic("TNF already active");
257 257 /*NOTREACHED*/
258 258 }
259 259
260 - } while (cas32((uint32_t *)&dtrace_vtime_active,
260 + } while (atomic_cas_32((uint32_t *)&dtrace_vtime_active,
261 261 state, nstate) != state);
262 262 }
263 263
264 264 void
265 265 dtrace_vtime_disable_tnf(void)
266 266 {
267 267 dtrace_vtime_state_t state, nstate;
268 268
269 269 do {
270 270 state = dtrace_vtime_active;
271 271
272 272 switch (state) {
273 273 case DTRACE_VTIME_ACTIVE_TNF:
274 274 nstate = DTRACE_VTIME_ACTIVE;
275 275 break;
276 276
|
↓ open down ↓ |
6 lines elided |
↑ open up ↑ |
277 277 case DTRACE_VTIME_INACTIVE_TNF:
278 278 nstate = DTRACE_VTIME_INACTIVE;
279 279 break;
280 280
281 281 case DTRACE_VTIME_ACTIVE:
282 282 case DTRACE_VTIME_INACTIVE:
283 283 panic("TNF already inactive");
284 284 /*NOTREACHED*/
285 285 }
286 286
287 - } while (cas32((uint32_t *)&dtrace_vtime_active,
287 + } while (atomic_cas_32((uint32_t *)&dtrace_vtime_active,
288 288 state, nstate) != state);
289 289 }
290 290
291 291 void
292 292 dtrace_vtime_switch(kthread_t *next)
293 293 {
294 294 dtrace_icookie_t cookie;
295 295 hrtime_t ts;
296 296
297 297 if (tnf_tracing_active) {
298 298 tnf_thread_switch(next);
299 299
300 300 if (dtrace_vtime_active == DTRACE_VTIME_INACTIVE_TNF)
301 301 return;
302 302 }
303 303
304 304 cookie = dtrace_interrupt_disable();
305 305 ts = dtrace_gethrtime();
306 306
307 307 if (curthread->t_dtrace_start != 0) {
308 308 curthread->t_dtrace_vtime += ts - curthread->t_dtrace_start;
309 309 curthread->t_dtrace_start = 0;
310 310 }
311 311
312 312 next->t_dtrace_start = ts;
313 313
314 314 dtrace_interrupt_enable(cookie);
315 315 }
316 316
317 317 void (*dtrace_fasttrap_fork_ptr)(proc_t *, proc_t *);
318 318 void (*dtrace_fasttrap_exec_ptr)(proc_t *);
319 319 void (*dtrace_fasttrap_exit_ptr)(proc_t *);
320 320
321 321 /*
322 322 * This function is called by cfork() in the event that it appears that
323 323 * there may be dtrace tracepoints active in the parent process's address
324 324 * space. This first confirms the existence of dtrace tracepoints in the
325 325 * parent process and calls into the fasttrap module to remove the
326 326 * corresponding tracepoints from the child. By knowing that there are
327 327 * existing tracepoints, and ensuring they can't be removed, we can rely
328 328 * on the fasttrap module remaining loaded.
329 329 */
330 330 void
331 331 dtrace_fasttrap_fork(proc_t *p, proc_t *cp)
332 332 {
333 333 ASSERT(p->p_proc_flag & P_PR_LOCK);
334 334 ASSERT(p->p_dtrace_count > 0);
335 335 ASSERT(dtrace_fasttrap_fork_ptr != NULL);
336 336
337 337 dtrace_fasttrap_fork_ptr(p, cp);
338 338 }
|
↓ open down ↓ |
41 lines elided |
↑ open up ↑ |
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX