tstTSC.cpp@ 11118

Last change on this file since 11118 was 8245, checked in by vboxsync, 17 years ago
rebranding: IPRT files again.
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1	/* $Id: tstTSC.cpp 8245 2008-04-21 17:24:28Z vboxsync $ */
2	/** @file
3	* IPRT Testcase - SMP TSC testcase.
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 Sun Microsystems, Inc.
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	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
27	* Clara, CA 95054 USA or visit http://www.sun.com if you need
28	* additional information or have any questions.
29	*/
30
31	/*******************************************************************************
32	* Header Files *
33	*******************************************************************************/
34	#include <iprt/runtime.h>
35
36	/*******************************************************************************
37	* Structures and Typedefs *
38	*******************************************************************************/
39	typedef struct TSCDATA
40	{
41	/** The TSC. */
42	uint64_t volatile TSC;
43	/** The APIC ID. */
44	uint8_t volatile u8ApicId;
45	/** Did it succeed? */
46	bool volatile fRead;
47	/** Did it fail? */
48	bool volatile fFailed;
49	/** The thread handle. */
50	RTTHREAD Thread;
51	} TSCDATA, *PTSCDATA;
52
53	/*******************************************************************************
54	* Global Variables *
55	*******************************************************************************/
56	/** The number of CPUs waiting on their user event semaphore. */
57	static volatile uint32_t g_cWaiting;
58	/** The number of CPUs ready (in spin) to do the TSC read. */
59	static volatile uint32_t g_cReady;
60	/** The variable the CPUs are spinning on.
61	* 0: Spin.
62	* 1: Go ahead.
63	* 2: You're too late, back to square one. */
64	static volatile uint32_t g_u32Go;
65	/** The number of CPUs that managed to read the TSC. */
66	static volatile uint32_t g_cRead;
67	/** The number of CPUs that failed to read the TSC. */
68	static volatile uint32_t g_cFailed;
69
70	/** Indicator forcing the threads to quit. */
71	static volatile bool g_fDone;
72
73
74	/*******************************************************************************
75	* Internal Functions *
76	*******************************************************************************/
77	static DECLCALLBACK(int) ThreadFunction(RTTHREAD Thread, void *pvUser);
78
79
80	/**
81	* Thread function for catching the other cpus.
82	*
83	* @returns VINF_SUCCESS (we don't care).
84	* @param Thread The thread handle.
85	* @param pvUser PTSCDATA.
86	*/
87	static DECLCALLBACK(int) ThreadFunction(RTTHREAD Thread, void *pvUser)
88	{
89	PTSCDATA pTscData = (PTSCDATA)pvUser;
90
91	while (!g_fDone)
92	{
93	/*
94	* Wait.
95	*/
96	ASMAtomicIncU32(&g_cWaiting);
97	RTThreadUserWait(Thread, RT_INDEFINITE_WAIT);
98	RTThreadUserReset(Thread);
99	ASMAtomicDecU32(&g_cWaiting);
100	if (g_fDone)
101	break;
102
103	/*
104	* Spin.
105	*/
106	ASMAtomicIncU32(&g_cReady);
107	while (!g_fDone)
108	{
109	const uint8_t ApicId1 = ASMGetApicId();
110	const uint64_t TSC1 = ASMReadTSC();
111	const uint32_t u32Go = g_u32Go;
112	if (u32Go == 0)
113	continue;
114
115	if (u32Go == 1)
116	{
117	/* do the reading. */
118	const uint8_t ApicId2 = ASMGetApicId();
119	const uint64_t TSC2 = ASMReadTSC();
120	const uint8_t ApicId3 = ASMGetApicId();
121	const uint64_t TSC3 = ASMReadTSC();
122	const uint8_t ApicId4 = ASMGetApicId();
123
124	if ( ApicId1 == ApicId2
125	&& ApicId1 == ApicId3
126	&& ApicId1 == ApicId4
127	&& TSC3 - TSC1 < 2250 /* WARNING: This is just a guess, increase if it doesn't work for you. */
128	&& TSC2 - TSC1 < TSC3 - TSC1
129	)
130	{
131	/* succeeded. */
132	pTscData->TSC = TSC2;
133	pTscData->u8ApicId = ApicId1;
134	pTscData->fFailed = false;
135	pTscData->fRead = true;
136	ASMAtomicIncU32(&g_cRead);
137	break;
138	}
139	}
140
141	/* failed */
142	pTscData->fFailed = true;
143	pTscData->fRead = false;
144	ASMAtomicIncU32(&g_cFailed);
145	break;
146	}
147	}
148
149	return VINF_SUCCESS;
150	}
151
152
153	int main()
154	{
155	RTR3Init();
156
157	/*
158	* This is only relevant to on SMP systems.
159	*/
160	const unsigned cCpus = RTSystemProcessorGetCount();
161	if (cCpus <= 1)
162	{
163	RTPrintf("tstTSC: SKIPPED - Only relevant on SMP systems\n");
164	return 0;
165	}
166
167	/*
168	* Create the threads.
169	*/
170	static TSCDATA s_aData[254];
171	uint32_t i;
172	if (cCpus > RT_ELEMENTS(s_aData))
173	{
174	RTPrintf("tstTSC: FAILED - too many CPUs (%u)\n", cCpus);
175	return 1;
176	}
177
178	/* ourselves. */
179	s_aData[0].Thread = RTThreadSelf();
180
181	/* the others */
182	for (i = 1; i < cCpus; i++)
183	{
184	int rc = RTThreadCreate(&s_aData[i].Thread, ThreadFunction, &s_aData[i], 0, RTTHREADTYPE_TIMER, RTTHREADFLAGS_WAITABLE, "OTHERCPU");
185	if (RT_FAILURE(rc))
186	{
187	RTPrintf("tstTSC: FAILURE - RTThreatCreate failed when creating thread #%u, rc=%Rrc!\n", i, rc);
188	ASMAtomicXchgSize(&g_fDone, true);
189	while (i-- > 1)
190	{
191	RTThreadUserSignal(s_aData[i].Thread);
192	RTThreadWait(s_aData[i].Thread, 5000, NULL);
193	}
194	return 1;
195	}
196	}
197
198	/*
199	* Retry untill we get lucky (or give up).
200	*/
201	for (unsigned cTries = 0; ; cTries++)
202	{
203	if (cTries > 10240)
204	{
205	RTPrintf("tstTSC: FAILURE - %d attempts, giving.\n", cTries);
206	break;
207	}
208
209	/*
210	* Wait for the other threads to get ready (brute force active wait, I'm lazy).
211	*/
212	i = 0;
213	while (g_cWaiting < cCpus - 1)
214	{
215	if (i++ > _2G32)
216	break;
217	RTThreadSleep(i & 0xf);
218	}
219	if (g_cWaiting != cCpus - 1)
220	{
221	RTPrintf("tstTSC: FAILURE - threads failed to get waiting (%d != %d (i=%d))\n", g_cWaiting + 1, cCpus, i);
222	break;
223	}
224
225	/*
226	* Send them spinning.
227	*/
228	ASMAtomicXchgU32(&g_cReady, 0);
229	ASMAtomicXchgU32(&g_u32Go, 0);
230	ASMAtomicXchgU32(&g_cRead, 0);
231	ASMAtomicXchgU32(&g_cFailed, 0);
232	for (i = 1; i < cCpus; i++)
233	{
234	ASMAtomicXchgSize(&s_aData[i].fFailed, false);
235	ASMAtomicXchgSize(&s_aData[i].fRead, false);
236	ASMAtomicXchgU8(&s_aData[i].u8ApicId, 0xff);
237
238	int rc = RTThreadUserSignal(s_aData[i].Thread);
239	if (RT_FAILURE(rc))
240	RTPrintf("tstTSC: WARNING - RTThreadUserSignal(%#u) -> rc=%Rrc!\n", i, rc);
241	}
242
243	/* wait for them to get ready. */
244	i = 0;
245	while (g_cReady < cCpus - 1)
246	{
247	if (i++ > _2G32)
248	break;
249	}
250	if (g_cReady != cCpus - 1)
251	{
252	RTPrintf("tstTSC: FAILURE - threads failed to get ready (%d != %d, i=%d)\n", g_cWaiting + 1, cCpus, i);
253	break;
254	}
255
256	/*
257	* Flip the "go" switch and do our readings.
258	* We give the other threads the slack it takes to two extra TSC and APIC ID reads.
259	*/
260	const uint8_t ApicId1 = ASMGetApicId();
261	const uint64_t TSC1 = ASMReadTSC();
262	ASMAtomicXchgU32(&g_u32Go, 1);
263	const uint8_t ApicId2 = ASMGetApicId();
264	const uint64_t TSC2 = ASMReadTSC();
265	const uint8_t ApicId3 = ASMGetApicId();
266	const uint64_t TSC3 = ASMReadTSC();
267	const uint8_t ApicId4 = ASMGetApicId();
268	const uint64_t TSC4 = ASMReadTSC();
269	ASMAtomicXchgU32(&g_u32Go, 2);
270	const uint8_t ApicId5 = ASMGetApicId();
271	const uint64_t TSC5 = ASMReadTSC();
272	const uint8_t ApicId6 = ASMGetApicId();
273
274	/* Compose our own result. */
275	if ( ApicId1 == ApicId2
276	&& ApicId1 == ApicId3
277	&& ApicId1 == ApicId4
278	&& ApicId1 == ApicId5
279	&& ApicId1 == ApicId6
280	&& TSC5 - TSC1 < 2750 /* WARNING: This is just a guess, increase if it doesn't work for you. */
281	&& TSC4 - TSC1 < TSC5 - TSC1
282	&& TSC3 - TSC1 < TSC4 - TSC1
283	&& TSC2 - TSC1 < TSC3 - TSC1
284	)
285	{
286	/* succeeded. */
287	s_aData[0].TSC = TSC2;
288	s_aData[0].u8ApicId = ApicId1;
289	s_aData[0].fFailed = false;
290	s_aData[0].fRead = true;
291	ASMAtomicIncU32(&g_cRead);
292	}
293	else
294	{
295	/* failed */
296	s_aData[0].fFailed = true;
297	s_aData[0].fRead = false;
298	ASMAtomicIncU32(&g_cFailed);
299	}
300
301	/*
302	* Wait a little while to let the other ones to finish.
303	*/
304	i = 0;
305	while (g_cRead + g_cFailed < cCpus)
306	{
307	if (i++ > _2G32)
308	break;
309	if (i > _1M)
310	RTThreadSleep(i & 0xf);
311	}
312	if (g_cRead + g_cFailed != cCpus)
313	{
314	RTPrintf("tstTSC: FAILURE - threads failed to complete reading (%d + %d != %d)\n", g_cRead, g_cFailed, cCpus);
315	break;
316	}
317
318	/*
319	* If everone succeeded, print the results.
320	*/
321	if (!g_cFailed)
322	{
323	/* sort it by apic id first. */
324	bool fDone;
325	do
326	{
327	for (i = 1, fDone = true; i < cCpus; i++)
328	if (s_aData[i - 1].u8ApicId > s_aData[i].u8ApicId)
329	{
330	TSCDATA Tmp = s_aData[i - 1];
331	s_aData[i - 1] = s_aData[i];
332	s_aData[i] = Tmp;
333	fDone = false;
334	}
335	} while (!fDone);
336
337	RTPrintf(" # ID TSC delta0 (decimal)\n"
338	"-----------------------------------------\n");
339	RTPrintf("%2d %02x %RX64\n", 0, s_aData[0].u8ApicId, s_aData[0].TSC);
340	for (i = 1; i < cCpus; i++)
341	RTPrintf("%2d %02x %RX64 %s%lld\n", i, s_aData[i].u8ApicId, s_aData[i].TSC,
342	s_aData[i].TSC > s_aData[0].TSC ? "+" : "", s_aData[i].TSC - s_aData[0].TSC);
343	RTPrintf("(Needed %u attempt%s.)\n", cTries + 1, cTries ? "s" : "");
344	break;
345	}
346	}
347
348	/*
349	* Destroy the threads.
350	*/
351	ASMAtomicXchgSize(&g_fDone, true);
352	for (i = 0; i < cCpus; i++)
353	if (s_aData[i].Thread != RTThreadSelf())
354	{
355	int rc = RTThreadUserSignal(s_aData[i].Thread);
356	if (RT_FAILURE(rc))
357	RTPrintf("tstTSC: WARNING - RTThreadUserSignal(%#u) -> rc=%Rrc! (2)\n", i, rc);
358	}
359	for (i = 0; i < cCpus; i++)
360	if (s_aData[i].Thread != RTThreadSelf())
361	{
362	int rc = RTThreadWait(s_aData[i].Thread, 5000, NULL);
363	if (RT_FAILURE(rc))
364	RTPrintf("tstTSC: WARNING - RTThreadWait(%#u) -> rc=%Rrc!\n", i, rc);
365	}
366
367	return g_cFailed != 0 \|\| g_cRead != cCpus;
368	}

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source: vbox/trunk/src/VBox/Runtime/testcase/tstTSC.cpp@ 11118

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