tstTSC.cpp@ 78253

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1	/* $Id: tstTSC.cpp 76553 2019-01-01 01:45:53Z vboxsync $ */
2	/** @file
3	* IPRT Testcase - SMP TSC testcase.
4	*/
5
6	/*
7	* Copyright (C) 2006-2019 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*********************************************************************************************************************************
29	* Header Files *
30	*********************************************************************************************************************************/
31	#include <iprt/asm-amd64-x86.h>
32	#include <iprt/asm.h>
33	#include <iprt/getopt.h>
34	#include <iprt/initterm.h>
35	#include <iprt/mp.h>
36	#include <iprt/stream.h>
37	#include <iprt/string.h>
38	#include <iprt/thread.h>
39	#include <iprt/time.h>
40
41
42	/*********************************************************************************************************************************
43	* Structures and Typedefs *
44	*********************************************************************************************************************************/
45	typedef struct TSCDATA
46	{
47	/** The TSC. */
48	uint64_t volatile TSC;
49	/** The APIC ID. */
50	uint8_t volatile u8ApicId;
51	/** Did it succeed? */
52	bool volatile fRead;
53	/** Did it fail? */
54	bool volatile fFailed;
55	/** The thread handle. */
56	RTTHREAD Thread;
57	} TSCDATA, *PTSCDATA;
58
59
60	/*********************************************************************************************************************************
61	* Global Variables *
62	*********************************************************************************************************************************/
63	/** The number of CPUs waiting on their user event semaphore. */
64	static volatile uint32_t g_cWaiting;
65	/** The number of CPUs ready (in spin) to do the TSC read. */
66	static volatile uint32_t g_cReady;
67	/** The variable the CPUs are spinning on.
68	* 0: Spin.
69	* 1: Go ahead.
70	* 2: You're too late, back to square one. */
71	static volatile uint32_t g_u32Go;
72	/** The number of CPUs that managed to read the TSC. */
73	static volatile uint32_t g_cRead;
74	/** The number of CPUs that failed to read the TSC. */
75	static volatile uint32_t g_cFailed;
76
77	/** Indicator forcing the threads to quit. */
78	static volatile bool g_fDone;
79
80
81	/*********************************************************************************************************************************
82	* Internal Functions *
83	*********************************************************************************************************************************/
84	static DECLCALLBACK(int) ThreadFunction(RTTHREAD Thread, void *pvUser);
85
86
87	/**
88	* Thread function for catching the other cpus.
89	*
90	* @returns VINF_SUCCESS (we don't care).
91	* @param Thread The thread handle.
92	* @param pvUser PTSCDATA.
93	*/
94	static DECLCALLBACK(int) ThreadFunction(RTTHREAD Thread, void *pvUser)
95	{
96	PTSCDATA pTscData = (PTSCDATA)pvUser;
97
98	while (!g_fDone)
99	{
100	/*
101	* Wait.
102	*/
103	ASMAtomicIncU32(&g_cWaiting);
104	RTThreadUserWait(Thread, RT_INDEFINITE_WAIT);
105	RTThreadUserReset(Thread);
106	ASMAtomicDecU32(&g_cWaiting);
107	if (g_fDone)
108	break;
109
110	/*
111	* Spin.
112	*/
113	ASMAtomicIncU32(&g_cReady);
114	while (!g_fDone)
115	{
116	const uint8_t ApicId1 = ASMGetApicId();
117	const uint64_t TSC1 = ASMReadTSC();
118	const uint32_t u32Go = g_u32Go;
119	if (u32Go == 0)
120	continue;
121
122	if (u32Go == 1)
123	{
124	/* do the reading. */
125	const uint8_t ApicId2 = ASMGetApicId();
126	const uint64_t TSC2 = ASMReadTSC();
127	const uint8_t ApicId3 = ASMGetApicId();
128	const uint64_t TSC3 = ASMReadTSC();
129	const uint8_t ApicId4 = ASMGetApicId();
130
131	if ( ApicId1 == ApicId2
132	&& ApicId1 == ApicId3
133	&& ApicId1 == ApicId4
134	&& TSC3 - TSC1 < 2250 /* WARNING: This is just a guess, increase if it doesn't work for you. */
135	&& TSC2 - TSC1 < TSC3 - TSC1
136	)
137	{
138	/* succeeded. */
139	pTscData->TSC = TSC2;
140	pTscData->u8ApicId = ApicId1;
141	pTscData->fFailed = false;
142	pTscData->fRead = true;
143	ASMAtomicIncU32(&g_cRead);
144	break;
145	}
146	}
147
148	/* failed */
149	pTscData->fFailed = true;
150	pTscData->fRead = false;
151	ASMAtomicIncU32(&g_cFailed);
152	break;
153	}
154	}
155
156	return VINF_SUCCESS;
157	}
158
159	static int tstTSCCalcDrift(void)
160	{
161	/*
162	* This is only relevant to on SMP systems.
163	*/
164	const unsigned cCpus = RTMpGetOnlineCount();
165	if (cCpus <= 1)
166	{
167	RTPrintf("tstTSC: SKIPPED - Only relevant on SMP systems\n");
168	return 0;
169	}
170
171	/*
172	* Create the threads.
173	*/
174	static TSCDATA s_aData[254];
175	uint32_t i;
176	if (cCpus > RT_ELEMENTS(s_aData))
177	{
178	RTPrintf("tstTSC: FAILED - too many CPUs (%u)\n", cCpus);
179	return 1;
180	}
181
182	/* ourselves. */
183	s_aData[0].Thread = RTThreadSelf();
184
185	/* the others */
186	for (i = 1; i < cCpus; i++)
187	{
188	int rc = RTThreadCreate(&s_aData[i].Thread, ThreadFunction, &s_aData[i], 0, RTTHREADTYPE_TIMER, RTTHREADFLAGS_WAITABLE, "OTHERCPU");
189	if (RT_FAILURE(rc))
190	{
191	RTPrintf("tstTSC: FAILURE - RTThreatCreate failed when creating thread #%u, rc=%Rrc!\n", i, rc);
192	ASMAtomicXchgSize(&g_fDone, true);
193	while (i-- > 1)
194	{
195	RTThreadUserSignal(s_aData[i].Thread);
196	RTThreadWait(s_aData[i].Thread, 5000, NULL);
197	}
198	return 1;
199	}
200	}
201
202	/*
203	* Retry until we get lucky (or give up).
204	*/
205	for (unsigned cTries = 0; ; cTries++)
206	{
207	if (cTries > 10240)
208	{
209	RTPrintf("tstTSC: FAILURE - %d attempts, giving.\n", cTries);
210	break;
211	}
212
213	/*
214	* Wait for the other threads to get ready (brute force active wait, I'm lazy).
215	*/
216	i = 0;
217	while (g_cWaiting < cCpus - 1)
218	{
219	if (i++ > _2G32)
220	break;
221	RTThreadSleep(i & 0xf);
222	}
223	if (g_cWaiting != cCpus - 1)
224	{
225	RTPrintf("tstTSC: FAILURE - threads failed to get waiting (%d != %d (i=%d))\n", g_cWaiting + 1, cCpus, i);
226	break;
227	}
228
229	/*
230	* Send them spinning.
231	*/
232	ASMAtomicXchgU32(&g_cReady, 0);
233	ASMAtomicXchgU32(&g_u32Go, 0);
234	ASMAtomicXchgU32(&g_cRead, 0);
235	ASMAtomicXchgU32(&g_cFailed, 0);
236	for (i = 1; i < cCpus; i++)
237	{
238	ASMAtomicXchgSize(&s_aData[i].fFailed, false);
239	ASMAtomicXchgSize(&s_aData[i].fRead, false);
240	ASMAtomicXchgU8(&s_aData[i].u8ApicId, 0xff);
241
242	int rc = RTThreadUserSignal(s_aData[i].Thread);
243	if (RT_FAILURE(rc))
244	RTPrintf("tstTSC: WARNING - RTThreadUserSignal(%#u) -> rc=%Rrc!\n", i, rc);
245	}
246
247	/* wait for them to get ready. */
248	i = 0;
249	while (g_cReady < cCpus - 1)
250	{
251	if (i++ > _2G32)
252	break;
253	}
254	if (g_cReady != cCpus - 1)
255	{
256	RTPrintf("tstTSC: FAILURE - threads failed to get ready (%d != %d, i=%d)\n", g_cWaiting + 1, cCpus, i);
257	break;
258	}
259
260	/*
261	* Flip the "go" switch and do our readings.
262	* We give the other threads the slack it takes to two extra TSC and APIC ID reads.
263	*/
264	const uint8_t ApicId1 = ASMGetApicId();
265	const uint64_t TSC1 = ASMReadTSC();
266	ASMAtomicXchgU32(&g_u32Go, 1);
267	const uint8_t ApicId2 = ASMGetApicId();
268	const uint64_t TSC2 = ASMReadTSC();
269	const uint8_t ApicId3 = ASMGetApicId();
270	const uint64_t TSC3 = ASMReadTSC();
271	const uint8_t ApicId4 = ASMGetApicId();
272	const uint64_t TSC4 = ASMReadTSC();
273	ASMAtomicXchgU32(&g_u32Go, 2);
274	const uint8_t ApicId5 = ASMGetApicId();
275	const uint64_t TSC5 = ASMReadTSC();
276	const uint8_t ApicId6 = ASMGetApicId();
277
278	/* Compose our own result. */
279	if ( ApicId1 == ApicId2
280	&& ApicId1 == ApicId3
281	&& ApicId1 == ApicId4
282	&& ApicId1 == ApicId5
283	&& ApicId1 == ApicId6
284	&& TSC5 - TSC1 < 2750 /* WARNING: This is just a guess, increase if it doesn't work for you. */
285	&& TSC4 - TSC1 < TSC5 - TSC1
286	&& TSC3 - TSC1 < TSC4 - TSC1
287	&& TSC2 - TSC1 < TSC3 - TSC1
288	)
289	{
290	/* succeeded. */
291	s_aData[0].TSC = TSC2;
292	s_aData[0].u8ApicId = ApicId1;
293	s_aData[0].fFailed = false;
294	s_aData[0].fRead = true;
295	ASMAtomicIncU32(&g_cRead);
296	}
297	else
298	{
299	/* failed */
300	s_aData[0].fFailed = true;
301	s_aData[0].fRead = false;
302	ASMAtomicIncU32(&g_cFailed);
303	}
304
305	/*
306	* Wait a little while to let the other ones to finish.
307	*/
308	i = 0;
309	while (g_cRead + g_cFailed < cCpus)
310	{
311	if (i++ > _2G32)
312	break;
313	if (i > _1M)
314	RTThreadSleep(i & 0xf);
315	}
316	if (g_cRead + g_cFailed != cCpus)
317	{
318	RTPrintf("tstTSC: FAILURE - threads failed to complete reading (%d + %d != %d)\n", g_cRead, g_cFailed, cCpus);
319	break;
320	}
321
322	/*
323	* If everone succeeded, print the results.
324	*/
325	if (!g_cFailed)
326	{
327	/* sort it by apic id first. */
328	bool fDone;
329	do
330	{
331	for (i = 1, fDone = true; i < cCpus; i++)
332	if (s_aData[i - 1].u8ApicId > s_aData[i].u8ApicId)
333	{
334	TSCDATA Tmp = s_aData[i - 1];
335	s_aData[i - 1] = s_aData[i];
336	s_aData[i] = Tmp;
337	fDone = false;
338	}
339	} while (!fDone);
340
341	RTPrintf(" # ID TSC delta0 (decimal)\n"
342	"-----------------------------------------\n");
343	RTPrintf("%2d %02x %RX64\n", 0, s_aData[0].u8ApicId, s_aData[0].TSC);
344	for (i = 1; i < cCpus; i++)
345	RTPrintf("%2d %02x %RX64 %s%lld\n", i, s_aData[i].u8ApicId, s_aData[i].TSC,
346	s_aData[i].TSC > s_aData[0].TSC ? "+" : "", s_aData[i].TSC - s_aData[0].TSC);
347	RTPrintf("(Needed %u attempt%s.)\n", cTries + 1, cTries ? "s" : "");
348	break;
349	}
350	}
351
352	/*
353	* Destroy the threads.
354	*/
355	ASMAtomicXchgSize(&g_fDone, true);
356	for (i = 0; i < cCpus; i++)
357	if (s_aData[i].Thread != RTThreadSelf())
358	{
359	int rc = RTThreadUserSignal(s_aData[i].Thread);
360	if (RT_FAILURE(rc))
361	RTPrintf("tstTSC: WARNING - RTThreadUserSignal(%#u) -> rc=%Rrc! (2)\n", i, rc);
362	}
363	for (i = 0; i < cCpus; i++)
364	if (s_aData[i].Thread != RTThreadSelf())
365	{
366	int rc = RTThreadWait(s_aData[i].Thread, 5000, NULL);
367	if (RT_FAILURE(rc))
368	RTPrintf("tstTSC: WARNING - RTThreadWait(%#u) -> rc=%Rrc!\n", i, rc);
369	}
370
371	return g_cFailed != 0 \|\| g_cRead != cCpus;
372	}
373
374
375	static int tstTSCCalcFrequency(uint32_t cMsDuration)
376	{
377	/*
378	* Sample the TSC and time, sleep the requested time and calc the deltas.
379	*/
380	uint64_t uNanoTS = RTTimeSystemNanoTS();
381	uint64_t uTSC = ASMReadTSC();
382	RTThreadSleep(cMsDuration);
383	uNanoTS = RTTimeSystemNanoTS() - uNanoTS;
384	uTSC = ASMReadTSC() - uTSC;
385
386	/*
387	* Calc the frequency.
388	*/
389	RTPrintf("tstTSC: %RU64 ticks in %RU64 ns\n", uTSC, uNanoTS);
390	uint64_t cHz = (uint64_t)(uTSC / ((long double)uNanoTS / (long double)1000000000));
391	RTPrintf("tstTSC: Frequency %RU64 Hz", cHz);
392	if (cHz > _1G)
393	{
394	cHz += _1G / 20;
395	RTPrintf(" %RU64.%RU64 GHz", cHz / _1G, (cHz % _1G) / (_1G / 10));
396	}
397	else if (cHz > _1M)
398	{
399	cHz += _1M / 20;
400	RTPrintf(" %RU64.%RU64 MHz", cHz / _1M, (cHz % _1M) / (_1M / 10));
401	}
402	RTPrintf("\n");
403	return 0;
404	}
405
406
407	int main(int argc, char **argv)
408	{
409	RTR3InitExe(argc, &argv, 0);
410
411	/*
412	* Parse arguments.
413	*/
414	bool fCalcFrequency = false;
415	uint32_t cMsDuration = 1000; /* 1 sec */
416	static const RTGETOPTDEF s_aOptions[] =
417	{
418	{ "--duration", 'd', RTGETOPT_REQ_UINT32 },
419	{ "--calc-frequency", 'f', RTGETOPT_REQ_NOTHING },
420	};
421	int ch;
422	RTGETOPTUNION Value;
423	RTGETOPTSTATE GetState;
424	RTGetOptInit(&GetState, argc, argv, s_aOptions, RT_ELEMENTS(s_aOptions), 1, 0 /* fFlags */);
425	while ((ch = RTGetOpt(&GetState, &Value)))
426	switch (ch)
427	{
428	case 'd': cMsDuration = Value.u32;
429	break;
430
431	case 'f': fCalcFrequency = true;
432	break;
433
434	case 'h':
435	RTPrintf("usage: tstTSC\n"
436	" or: tstTSC <-f\|--calc-frequency> [--duration\|-d ms]\n");
437	return 1;
438
439	case 'V':
440	RTPrintf("$Revision: 76553 $\n");
441	return 0;
442
443	default:
444	return RTGetOptPrintError(ch, &Value);
445	}
446
447	if (fCalcFrequency)
448	return tstTSCCalcFrequency(cMsDuration);
449	return tstTSCCalcDrift();
450	}
451

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source: vbox/trunk/src/VBox/Runtime/testcase/tstTSC.cpp@ 78253

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