bs3-timing-1-32.c32@ 93115

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1	/* $Id: bs3-timing-1-32.c32 93115 2022-01-01 11:31:46Z vboxsync $ */
2	/** @file
3	* BS3Kit - bs3-timinig-1, 32-bit C code.
4	*/
5
6	/*
7	* Copyright (C) 2007-2022 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	#ifndef STANDALONE_EXECUTABLE
32	# include <bs3kit.h>
33	#endif
34	#include <iprt/asm-amd64-x86.h>
35	#include <iprt/asm-math.h>
36	#include <iprt/asm.h>
37	#include <iprt/uint128.h>
38
39
40	/*********************************************************************************************************************************
41	* Structures and Typedefs *
42	*********************************************************************************************************************************/
43	/** TSC timing results. */
44	typedef struct BS3TIMING1RESULT
45	{
46	/** Number of nanoseconds elapsed while testing. */
47	uint64_t cNsElapsed;
48	/** Number of CPU ticks elapsed while testing. */
49	uint64_t cTicksElapsed;
50	/** The minium number of ticks between TSC reads. */
51	uint64_t cTicksMin;
52	/** The maximum number of ticks between TSC reads. */
53	uint64_t cTicksMax;
54	/** The sum of all TSC read deltas. */
55	uint64_t cTicksSum;
56	/** Number of loops (TSC read deltas). */
57	uint64_t cTotalLoops;
58	/** Number of times TSC moved backwards. */
59	uint64_t cBackwards;
60	/** Approx log2(cTicks) distribution. */
61	uint64_t aDistribution[65];
62	} BS3TIMING1RESULT;
63
64
65	/*********************************************************************************************************************************
66	* Global Variables *
67	*********************************************************************************************************************************/
68	/** The total result. */
69	static BS3TIMING1RESULT g_TotalResult;
70
71	/** Set if history wrapped (i.e. table is full). */
72	static bool g_fBigHistoryWrapped = false;
73	/** The next history entry. */
74	static uint32_t g_iBigHistory;
75	/** History of large gaps. */
76	static struct { uint64_t uTsc, cTicksDelta; } g_aBigHistory[384];
77
78
79
80	/**
81	* Pretty prints
82	*/
83	static void bs3Timing1_PrintTicks(uint64_t cTicks, uint64_t uCpuFreq)
84	{
85	if (uCpuFreq > _128M)
86	{
87	if (cTicks >= uCpuFreq * 1000)
88	Bs3TestPrintf("%'RU64s", cTicks / uCpuFreq);
89	else
90	{
91	const char *pszUnit;
92	uint64_t uValue;
93	if (cTicks >= uCpuFreq)
94	{
95	pszUnit = "s";
96	uValue = (cTicks * RT_MS_1SEC) / uCpuFreq;
97	}
98	else if (cTicks * RT_MS_1SEC >= uCpuFreq)
99	{
100	pszUnit = "ms";
101	uValue = (cTicks * RT_US_1SEC) / uCpuFreq;
102	}
103	else if (cTicks * RT_US_1SEC >= uCpuFreq)
104	{
105	pszUnit = "us";
106	uValue = (cTicks * RT_NS_1SEC) / uCpuFreq;
107	}
108	else if (cTicks * RT_NS_1SEC >= uCpuFreq)
109	{
110	pszUnit = "ns";
111	uValue = (cTicks * UINT64_C(1000000000000)) / uCpuFreq;
112	}
113	else
114	{
115	Bs3TestPrintf("%'RU64ps", (cTicks * UINT64_C(1000000000000)) / uCpuFreq);
116	return;
117	}
118	Bs3TestPrintf("%u.%03u%s (%'RU64 ticks)", (uint32_t)uValue / 1000, (uint32_t)uValue % 1000, pszUnit, cTicks);
119	}
120	}
121	else
122	Bs3TestPrintf("%'RU64 ticks", cTicks);
123	}
124
125
126	/**
127	* Prints a result.
128	*
129	* @param pResult The result to print.
130	* @param iRun The run (loop in qpc parlance).
131	* @param uVerbosity The verbosity level.
132	*/
133	static void bs3Timing1_PrintResult(BS3TIMING1RESULT const *pResult, unsigned iRun, unsigned uVerbosity)
134	{
135	uint64_t uCpuFreq;
136
137	/*
138	* Calc CPU frequency.
139	*/
140	if (pResult->cNsElapsed > 0 && pResult->cTicksElapsed > 0)
141	{
142	#if 1
143	RTUINT128U Tmp1, Divisor, Result;
144	RTUInt128Div(&Result,
145	RTUInt128MulU64ByU64(&Tmp1, pResult->cTicksElapsed, RT_NS_1SEC),
146	RTUInt128AssignU64(&Divisor, pResult->cNsElapsed));
147	uCpuFreq = Result.s.Lo;
148	#else
149	unsigned const cShift = pResult->cTicksElapsed < UINT64_C(0x000225C17D04) ? 0
150	: pResult->cTicksElapsed < UINT64_C(0x00225C17D04D) ? 4
151	: pResult->cTicksElapsed < UINT64_C(0x0225C17D04DA) ? 8
152	: pResult->cTicksElapsed < UINT64_C(0x225C1D940BF6) ? 12
153	: 16;
154	uCpuFreq = pResult->cTicksElapsed * ((uint64_t)RT_NS_1SEC >> cShift) / (pResult->cNsElapsed >> cShift);
155	#endif
156	}
157	else
158	uCpuFreq = 1;
159
160	/*
161	* Report results.
162	*
163	* Note! in 32-bit and 16-bit mode, values 4G or higher gets formatted as
164	* hexadecimal to avoid 64-bit division.
165	*/
166	Bs3TestPrintf("Loop #%u: %'RU64 tests: ", iRun, pResult->cTotalLoops);
167
168	Bs3TestPrintf("average ");
169	bs3Timing1_PrintTicks(pResult->cTicksSum / pResult->cTotalLoops, uCpuFreq);
170	Bs3TestPrintf(", min ");
171	bs3Timing1_PrintTicks(pResult->cTicksMin, uCpuFreq);
172	Bs3TestPrintf(", max ");
173	bs3Timing1_PrintTicks(pResult->cTicksMax, uCpuFreq);
174	Bs3TestPrintf("\n");
175
176	/* Distribution (tick delta log2-ish). */
177	if (uVerbosity > 0)
178	{
179	unsigned iItem = 0;
180	unsigned i;
181	for (i = uVerbosity > 1 ? 0 : 5; i < RT_ELEMENTS(pResult->aDistribution); i++)
182	if (pResult->aDistribution[i] != 0)
183	{
184	if (iItem >= 6)
185	{
186	iItem = 0;
187	Bs3TestPrintf("\n");
188	}
189	iItem++;
190	Bs3TestPrintf(" %'11RU64\|2^%-2u", pResult->aDistribution[i], i);
191	}
192	if (uVerbosity > 1)
193	Bs3TestPrintf(iItem < 6 ? " (%'RU64 Hz)\n" : "\n (%'RU64 Hz)\n", uCpuFreq);
194	else
195	Bs3TestPrintf("\n");
196	}
197	if (pResult->cBackwards != 0)
198	Bs3TestFailedF("TSC went backwards %'RU64 time(s)", pResult->cBackwards);
199	}
200
201
202	/**
203	* Do one TSC timing iteration.
204	*
205	* @param iRun The iteration number (loop).
206	* @param cSecs The number of seconds to sample TSCs.
207	* @param uVerbosity The noise level.
208	* @param iMinHistory The threshold level to put stuff in g_auTscHistory.
209	*/
210	static void bs3Timing1_Tsc_One(unsigned iRun, uint32_t cSecs, unsigned uVerbosity, unsigned iMinHistory)
211	{
212	uint64_t const nsStart = Bs3TestNow();
213	uint64_t const uTscStart = ASMReadTSC();
214	uint64_t const nsDeadline = nsStart + cSecs * RT_NS_1SEC_64;
215	uint64_t cNsElapsed;
216	BS3TIMING1RESULT Result;
217	unsigned i;
218
219	Bs3MemZero(&Result, sizeof(Result));
220	Result.cTicksMin = UINT64_MAX;
221
222	/*
223	* Test loop.
224	*/
225	do
226	{
227	unsigned cLoops = 100000 + 1;
228	Result.cTotalLoops += cLoops - 1;
229	while (--cLoops != 0)
230	{
231	uint64_t uTscPrev = ASMReadTSC();
232	uint64_t uTscNow = ASMReadTSC();
233	uint64_t cTicks = uTscNow - uTscPrev;
234	unsigned iBit;
235
236	/* check that it doesn't go backwards*/
237	if ((int64_t)cTicks < 0)
238	Result.cBackwards++;
239
240	/* min/max/avg */
241	Result.cTicksSum += cTicks;
242	if (cTicks < Result.cTicksMin)
243	Result.cTicksMin = cTicks;
244	if (cTicks > Result.cTicksMax)
245	Result.cTicksMax = cTicks;
246
247	/* result distribution by most significant bit. */
248	iBit = ASMBitLastSetU64(cTicks);
249	Result.aDistribution[iBit] += 1;
250	if (iBit < iMinHistory)
251	{ /* likely */ }
252	else
253	{
254	g_aBigHistory[g_iBigHistory].uTsc = uTscPrev;
255	g_aBigHistory[g_iBigHistory].cTicksDelta = cTicks;
256	if (++g_iBigHistory >= RT_ELEMENTS(g_aBigHistory))
257	{
258	g_iBigHistory = 0;
259	g_fBigHistoryWrapped = true;
260	}
261	}
262	}
263	} while ((cNsElapsed = Bs3TestNow()) < nsDeadline);
264
265	Result.cTicksElapsed = ASMReadTSC() - uTscStart;
266	Result.cNsElapsed = cNsElapsed - nsStart;
267
268	bs3Timing1_PrintResult(&Result, iRun, uVerbosity);
269
270	/* Add to total. */
271	g_TotalResult.cNsElapsed += Result.cNsElapsed;
272	g_TotalResult.cTicksElapsed += Result.cTicksElapsed;
273	if (Result.cTicksMin < g_TotalResult.cTicksMin \|\| g_TotalResult.cTicksMin == 0)
274	g_TotalResult.cTicksMin = Result.cTicksMin;
275	if (Result.cTicksMax > g_TotalResult.cTicksMax)
276	g_TotalResult.cTicksMax += Result.cTicksMax;
277	g_TotalResult.cTicksSum += Result.cTicksSum;
278	g_TotalResult.cTotalLoops += Result.cTotalLoops;
279	g_TotalResult.cBackwards += Result.cBackwards;
280	for (i = 0; i < RT_ELEMENTS(Result.aDistribution); i++)
281	g_TotalResult.aDistribution[i] += Result.aDistribution[i];
282	}
283
284
285	/**
286	* The TSC test driver.
287	*
288	* @param cLoops Number of test iterations.
289	* @param cSecs The number of seconds per iteration.
290	* @param uVerbosity How noisy we should be.
291	* @param iMinHistory The threshold for big gap history.
292	*/
293	static void bs3Timing1_Tsc_Driver(unsigned cLoops, unsigned cSecs, unsigned uVerbosity, unsigned iMinHistory)
294	{
295	unsigned iLoop;
296
297	#if 1
298	/*
299	* Verify that the first/last bit in U64 works (didn't).
300	*/
301	iLoop = ASMBitLastSetU64( UINT64_C(0x1000100010001000)); if (iLoop != 61) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
302	iLoop = ASMBitFirstSetU64(UINT64_C(0x1000100010001000)); if (iLoop != 13) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
303	iLoop = ASMBitLastSetU64( UINT64_C(0x000ffff000000000)); if (iLoop != 52) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
304	iLoop = ASMBitFirstSetU64(UINT64_C(0x000ffff000000000)); if (iLoop != 37) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
305	#endif
306
307	/*
308	* Do the work.
309	*/
310	Bs3TestPrintf("Running %u loops, %u second%s each...\n", cLoops, cSecs, cSecs != 1 ? "s" : "");
311	for (iLoop = 1; iLoop <= cLoops; iLoop++)
312	bs3Timing1_Tsc_One(iLoop, cSecs, uVerbosity, iMinHistory);
313
314	/*
315	* Report the total.
316	*/
317	Bs3TestPrintf("Total:\n");
318	bs3Timing1_PrintResult(&g_TotalResult, iLoop, uVerbosity + 1);
319
320	/*
321	* Dump the large gap history, if any.
322	*/
323	if (g_fBigHistoryWrapped \|\| g_iBigHistory > 0)
324	{
325	uint32_t const iFirst = g_fBigHistoryWrapped ? g_iBigHistory : 0;
326	uint32_t const iEnd = g_iBigHistory;
327	uint64_t uTscPrev = g_aBigHistory[iFirst].uTsc;
328	uint32_t i = iFirst;
329	Bs3TestPrintf("Big gap history (TSC, prev delta, test delta\|level):\n");
330	do
331	{
332	Bs3TestPrintf(" %'RU64: %'14RU64 - %'14RU64\|%u\n", g_aBigHistory[i].uTsc, g_aBigHistory[i].uTsc - uTscPrev,
333	g_aBigHistory[i].cTicksDelta, ASMBitLastSetU64(g_aBigHistory[i].cTicksDelta));
334	uTscPrev = g_aBigHistory[i].uTsc;
335	if (++i >= RT_ELEMENTS(g_aBigHistory))
336	i = 0;
337	} while (i != iEnd);
338	}
339	else
340	Bs3TestPrintf("No big gap history.\n");
341	}
342
343
344	#ifndef STANDALONE_EXECUTABLE
345	BS3_DECL(void) bs3Timing1_Tsc_pe32(void)
346	{
347	Bs3TestPrintf("bs3Timing1_Tsc_pe32\n");
348	bs3Timing1_Tsc_Driver(60, 10 /sec/, 1 /uVerbosity/, 17);
349	}
350	#endif
351
352	/* P.S. don't forget: VBoxManage setextradata bs3-timing-1 VBoxInternal/Devices/VMMDev/0/Config/TestingEnabled 1 */
353

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