| dtrace_subr.c (194850) | dtrace_subr.c (195710) |
|---|---|
| 1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * --- 5 unchanged lines hidden (view full) --- 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 * | 1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * --- 5 unchanged lines hidden (view full) --- 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 * |
| 22 * $FreeBSD: head/sys/cddl/dev/dtrace/amd64/dtrace_subr.c 194850 2009-06-24 16:03:57Z avg $ | 22 * $FreeBSD: head/sys/cddl/dev/dtrace/amd64/dtrace_subr.c 195710 2009-07-15 17:07:39Z avg $ |
| 23 * 24 */ 25/* 26 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30#include <sys/param.h> --- 330 unchanged lines hidden (view full) --- 361 362 return (1); 363} 364#endif 365 366static int64_t tgt_cpu_tsc; 367static int64_t hst_cpu_tsc; 368static int64_t tsc_skew[MAXCPU]; | 23 * 24 */ 25/* 26 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30#include <sys/param.h> --- 330 unchanged lines hidden (view full) --- 361 362 return (1); 363} 364#endif 365 366static int64_t tgt_cpu_tsc; 367static int64_t hst_cpu_tsc; 368static int64_t tsc_skew[MAXCPU]; |
| 369static uint64_t nsec_scale; |
|
| 369 | 370 |
| 371/* See below for the explanation of this macro. */ 372#define SCALE_SHIFT 28 373 |
|
| 370static void 371dtrace_gethrtime_init_sync(void *arg) 372{ 373#ifdef CHECK_SYNC 374 /* 375 * Delay this function from returning on one 376 * of the CPUs to check that the synchronisation 377 * works. --- 18 unchanged lines hidden (view full) --- 396 tgt_cpu_tsc = rdtsc(); 397 else 398 hst_cpu_tsc = rdtsc(); 399} 400 401static void 402dtrace_gethrtime_init(void *arg) 403{ | 374static void 375dtrace_gethrtime_init_sync(void *arg) 376{ 377#ifdef CHECK_SYNC 378 /* 379 * Delay this function from returning on one 380 * of the CPUs to check that the synchronisation 381 * works. --- 18 unchanged lines hidden (view full) --- 400 tgt_cpu_tsc = rdtsc(); 401 else 402 hst_cpu_tsc = rdtsc(); 403} 404 405static void 406dtrace_gethrtime_init(void *arg) 407{ |
| 408 uint64_t tsc_f; |
|
| 404 cpumask_t map; 405 int i; | 409 cpumask_t map; 410 int i; |
| 406 struct pcpu *cp; | |
| 407 | 411 |
| 412 /* 413 * Get TSC frequency known at this moment. 414 * This should be constant if TSC is invariant. 415 * Otherwise tick->time conversion will be inaccurate, but 416 * will preserve monotonic property of TSC. 417 */ 418 tsc_f = tsc_freq; 419 420 /* 421 * The following line checks that nsec_scale calculated below 422 * doesn't overflow 32-bit unsigned integer, so that it can multiply 423 * another 32-bit integer without overflowing 64-bit. 424 * Thus minimum supported TSC frequency is 62.5MHz. 425 */ 426 KASSERT(tsc_f > (NANOSEC >> (32 - SCALE_SHIFT)), ("TSC frequency is too low")); 427 428 /* 429 * We scale up NANOSEC/tsc_f ratio to preserve as much precision 430 * as possible. 431 * 2^28 factor was chosen quite arbitrarily from practical 432 * considerations: 433 * - it supports TSC frequencies as low as 62.5MHz (see above); 434 * - it provides quite good precision (e < 0.01%) up to THz 435 * (terahertz) values; 436 */ 437 nsec_scale = ((uint64_t)NANOSEC << SCALE_SHIFT) / tsc_f; 438 |
|
| 408 /* The current CPU is the reference one. */ 409 tsc_skew[curcpu] = 0; 410 411 for (i = 0; i <= mp_maxid; i++) { 412 if (i == curcpu) 413 continue; 414 | 439 /* The current CPU is the reference one. */ 440 tsc_skew[curcpu] = 0; 441 442 for (i = 0; i <= mp_maxid; i++) { 443 if (i == curcpu) 444 continue; 445 |
| 415 if ((cp = pcpu_find(i)) == NULL) | 446 if (pcpu_find(i) == NULL) |
| 416 continue; 417 418 map = 0; 419 map |= (1 << curcpu); 420 map |= (1 << i); 421 422 smp_rendezvous_cpus(map, dtrace_gethrtime_init_sync, 423 dtrace_gethrtime_init_cpu, --- 10 unchanged lines hidden (view full) --- 434 * be called from a probe context and guaranteed not to have 435 * instrumented with probes itself. 436 * 437 * Returns nanoseconds since boot. 438 */ 439uint64_t 440dtrace_gethrtime() 441{ | 447 continue; 448 449 map = 0; 450 map |= (1 << curcpu); 451 map |= (1 << i); 452 453 smp_rendezvous_cpus(map, dtrace_gethrtime_init_sync, 454 dtrace_gethrtime_init_cpu, --- 10 unchanged lines hidden (view full) --- 465 * be called from a probe context and guaranteed not to have 466 * instrumented with probes itself. 467 * 468 * Returns nanoseconds since boot. 469 */ 470uint64_t 471dtrace_gethrtime() 472{ |
| 442 return ((rdtsc() + tsc_skew[curcpu]) * (int64_t) 1000000000 / tsc_freq); | 473 uint64_t tsc; 474 uint32_t lo; 475 uint32_t hi; 476 477 /* 478 * We split TSC value into lower and higher 32-bit halves and separately 479 * scale them with nsec_scale, then we scale them down by 2^28 480 * (see nsec_scale calculations) taking into account 32-bit shift of 481 * the higher half and finally add. 482 */ 483 tsc = rdtsc() + tsc_skew[curcpu]; 484 lo = tsc; 485 hi = tsc >> 32; 486 return (((lo * nsec_scale) >> SCALE_SHIFT) + 487 ((hi * nsec_scale) << (32 - SCALE_SHIFT))); |
| 443} 444 445uint64_t 446dtrace_gethrestime(void) 447{ 448 printf("%s(%d): XXX\n",__func__,__LINE__); 449 return (0); 450} --- 56 unchanged lines hidden --- | 488} 489 490uint64_t 491dtrace_gethrestime(void) 492{ 493 printf("%s(%d): XXX\n",__func__,__LINE__); 494 return (0); 495} --- 56 unchanged lines hidden --- |