bs3-timing-1-32.c32@ 96455

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1	/* $Id: bs3-timing-1-32.c32 96407 2022-08-22 17:43:14Z vboxsync $ */
2	/** @file
3	* BS3Kit - bs3-timinig-1, 32-bit C code.
4	*/
5
6	/*
7	* Copyright (C) 2007-2022 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* The contents of this file may alternatively be used under the terms
26	* of the Common Development and Distribution License Version 1.0
27	* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28	* in the VirtualBox distribution, in which case the provisions of the
29	* CDDL are applicable instead of those of the GPL.
30	*
31	* You may elect to license modified versions of this file under the
32	* terms and conditions of either the GPL or the CDDL or both.
33	*
34	* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35	*/
36
37
38	/*********************************************************************************************************************************
39	* Header Files *
40	*********************************************************************************************************************************/
41	#ifndef STANDALONE_EXECUTABLE
42	# include <bs3kit.h>
43	#endif
44	#include <iprt/asm-amd64-x86.h>
45	#include <iprt/asm-math.h>
46	#include <iprt/asm.h>
47	#include <iprt/uint128.h>
48
49
50	/*********************************************************************************************************************************
51	* Structures and Typedefs *
52	*********************************************************************************************************************************/
53	/** TSC timing results. */
54	typedef struct BS3TIMING1RESULT
55	{
56	/** Number of nanoseconds elapsed while testing. */
57	uint64_t cNsElapsed;
58	/** Number of CPU ticks elapsed while testing. */
59	uint64_t cTicksElapsed;
60	/** The minium number of ticks between TSC reads. */
61	uint64_t cTicksMin;
62	/** The maximum number of ticks between TSC reads. */
63	uint64_t cTicksMax;
64	/** The sum of all TSC read deltas. */
65	uint64_t cTicksSum;
66	/** Number of loops (TSC read deltas). */
67	uint64_t cTotalLoops;
68	/** Number of times TSC moved backwards. */
69	uint64_t cBackwards;
70	/** Approx log2(cTicks) distribution. */
71	uint64_t aDistribution[65];
72	} BS3TIMING1RESULT;
73
74
75	/*********************************************************************************************************************************
76	* Global Variables *
77	*********************************************************************************************************************************/
78	/** The total result. */
79	static BS3TIMING1RESULT g_TotalResult;
80
81	/** Set if history wrapped (i.e. table is full). */
82	static bool g_fBigHistoryWrapped = false;
83	/** The next history entry. */
84	static uint32_t g_iBigHistory;
85	/** History of large gaps. */
86	static struct { uint64_t uTsc, cTicksDelta; } g_aBigHistory[384];
87
88
89
90	/**
91	* Pretty prints
92	*/
93	static void bs3Timing1_PrintTicks(uint64_t cTicks, uint64_t uCpuFreq)
94	{
95	if (uCpuFreq > _128M)
96	{
97	if (cTicks >= uCpuFreq * 1000)
98	Bs3TestPrintf("%'RU64s", cTicks / uCpuFreq);
99	else
100	{
101	const char *pszUnit;
102	uint64_t uValue;
103	if (cTicks >= uCpuFreq)
104	{
105	pszUnit = "s";
106	uValue = (cTicks * RT_MS_1SEC) / uCpuFreq;
107	}
108	else if (cTicks * RT_MS_1SEC >= uCpuFreq)
109	{
110	pszUnit = "ms";
111	uValue = (cTicks * RT_US_1SEC) / uCpuFreq;
112	}
113	else if (cTicks * RT_US_1SEC >= uCpuFreq)
114	{
115	pszUnit = "us";
116	uValue = (cTicks * RT_NS_1SEC) / uCpuFreq;
117	}
118	else if (cTicks * RT_NS_1SEC >= uCpuFreq)
119	{
120	pszUnit = "ns";
121	uValue = (cTicks * UINT64_C(1000000000000)) / uCpuFreq;
122	}
123	else
124	{
125	Bs3TestPrintf("%'RU64ps", (cTicks * UINT64_C(1000000000000)) / uCpuFreq);
126	return;
127	}
128	Bs3TestPrintf("%u.%03u%s (%'RU64 ticks)", (uint32_t)uValue / 1000, (uint32_t)uValue % 1000, pszUnit, cTicks);
129	}
130	}
131	else
132	Bs3TestPrintf("%'RU64 ticks", cTicks);
133	}
134
135
136	/**
137	* Prints a result.
138	*
139	* @param pResult The result to print.
140	* @param iRun The run (loop in qpc parlance).
141	* @param uVerbosity The verbosity level.
142	*/
143	static void bs3Timing1_PrintResult(BS3TIMING1RESULT const *pResult, unsigned iRun, unsigned uVerbosity)
144	{
145	uint64_t uCpuFreq;
146
147	/*
148	* Calc CPU frequency.
149	*/
150	if (pResult->cNsElapsed > 0 && pResult->cTicksElapsed > 0)
151	{
152	#if 1
153	RTUINT128U Tmp1, Divisor, Result;
154	RTUInt128Div(&Result,
155	RTUInt128MulU64ByU64(&Tmp1, pResult->cTicksElapsed, RT_NS_1SEC),
156	RTUInt128AssignU64(&Divisor, pResult->cNsElapsed));
157	uCpuFreq = Result.s.Lo;
158	#else
159	unsigned const cShift = pResult->cTicksElapsed < UINT64_C(0x000225C17D04) ? 0
160	: pResult->cTicksElapsed < UINT64_C(0x00225C17D04D) ? 4
161	: pResult->cTicksElapsed < UINT64_C(0x0225C17D04DA) ? 8
162	: pResult->cTicksElapsed < UINT64_C(0x225C1D940BF6) ? 12
163	: 16;
164	uCpuFreq = pResult->cTicksElapsed * ((uint64_t)RT_NS_1SEC >> cShift) / (pResult->cNsElapsed >> cShift);
165	#endif
166	}
167	else
168	uCpuFreq = 1;
169
170	/*
171	* Report results.
172	*
173	* Note! in 32-bit and 16-bit mode, values 4G or higher gets formatted as
174	* hexadecimal to avoid 64-bit division.
175	*/
176	Bs3TestPrintf("Loop #%u: %'RU64 tests: ", iRun, pResult->cTotalLoops);
177
178	Bs3TestPrintf("average ");
179	bs3Timing1_PrintTicks(pResult->cTicksSum / pResult->cTotalLoops, uCpuFreq);
180	Bs3TestPrintf(", min ");
181	bs3Timing1_PrintTicks(pResult->cTicksMin, uCpuFreq);
182	Bs3TestPrintf(", max ");
183	bs3Timing1_PrintTicks(pResult->cTicksMax, uCpuFreq);
184	Bs3TestPrintf("\n");
185
186	/* Distribution (tick delta log2-ish). */
187	if (uVerbosity > 0)
188	{
189	unsigned iItem = 0;
190	unsigned i;
191	for (i = uVerbosity > 1 ? 0 : 5; i < RT_ELEMENTS(pResult->aDistribution); i++)
192	if (pResult->aDistribution[i] != 0)
193	{
194	if (iItem >= 6)
195	{
196	iItem = 0;
197	Bs3TestPrintf("\n");
198	}
199	iItem++;
200	Bs3TestPrintf(" %'11RU64\|2^%-2u", pResult->aDistribution[i], i);
201	}
202	if (uVerbosity > 1)
203	Bs3TestPrintf(iItem < 6 ? " (%'RU64 Hz)\n" : "\n (%'RU64 Hz)\n", uCpuFreq);
204	else
205	Bs3TestPrintf("\n");
206	}
207	if (pResult->cBackwards != 0)
208	Bs3TestFailedF("TSC went backwards %'RU64 time(s)", pResult->cBackwards);
209	}
210
211
212	/**
213	* Do one TSC timing iteration.
214	*
215	* @param iRun The iteration number (loop).
216	* @param cSecs The number of seconds to sample TSCs.
217	* @param uVerbosity The noise level.
218	* @param iMinHistory The threshold level to put stuff in g_auTscHistory.
219	*/
220	static void bs3Timing1_Tsc_One(unsigned iRun, uint32_t cSecs, unsigned uVerbosity, unsigned iMinHistory)
221	{
222	uint64_t const nsStart = Bs3TestNow();
223	uint64_t const uTscStart = ASMReadTSC();
224	uint64_t const nsDeadline = nsStart + cSecs * RT_NS_1SEC_64;
225	uint64_t cNsElapsed;
226	BS3TIMING1RESULT Result;
227	unsigned i;
228
229	Bs3MemZero(&Result, sizeof(Result));
230	Result.cTicksMin = UINT64_MAX;
231
232	/*
233	* Test loop.
234	*/
235	do
236	{
237	unsigned cLoops = 100000 + 1;
238	Result.cTotalLoops += cLoops - 1;
239	while (--cLoops != 0)
240	{
241	uint64_t uTscPrev = ASMReadTSC();
242	uint64_t uTscNow = ASMReadTSC();
243	uint64_t cTicks = uTscNow - uTscPrev;
244	unsigned iBit;
245
246	/* check that it doesn't go backwards*/
247	if ((int64_t)cTicks < 0)
248	Result.cBackwards++;
249
250	/* min/max/avg */
251	Result.cTicksSum += cTicks;
252	if (cTicks < Result.cTicksMin)
253	Result.cTicksMin = cTicks;
254	if (cTicks > Result.cTicksMax)
255	Result.cTicksMax = cTicks;
256
257	/* result distribution by most significant bit. */
258	iBit = ASMBitLastSetU64(cTicks);
259	Result.aDistribution[iBit] += 1;
260	if (iBit < iMinHistory)
261	{ /* likely */ }
262	else
263	{
264	g_aBigHistory[g_iBigHistory].uTsc = uTscPrev;
265	g_aBigHistory[g_iBigHistory].cTicksDelta = cTicks;
266	if (++g_iBigHistory >= RT_ELEMENTS(g_aBigHistory))
267	{
268	g_iBigHistory = 0;
269	g_fBigHistoryWrapped = true;
270	}
271	}
272	}
273	} while ((cNsElapsed = Bs3TestNow()) < nsDeadline);
274
275	Result.cTicksElapsed = ASMReadTSC() - uTscStart;
276	Result.cNsElapsed = cNsElapsed - nsStart;
277
278	bs3Timing1_PrintResult(&Result, iRun, uVerbosity);
279
280	/* Add to total. */
281	g_TotalResult.cNsElapsed += Result.cNsElapsed;
282	g_TotalResult.cTicksElapsed += Result.cTicksElapsed;
283	if (Result.cTicksMin < g_TotalResult.cTicksMin \|\| g_TotalResult.cTicksMin == 0)
284	g_TotalResult.cTicksMin = Result.cTicksMin;
285	if (Result.cTicksMax > g_TotalResult.cTicksMax)
286	g_TotalResult.cTicksMax += Result.cTicksMax;
287	g_TotalResult.cTicksSum += Result.cTicksSum;
288	g_TotalResult.cTotalLoops += Result.cTotalLoops;
289	g_TotalResult.cBackwards += Result.cBackwards;
290	for (i = 0; i < RT_ELEMENTS(Result.aDistribution); i++)
291	g_TotalResult.aDistribution[i] += Result.aDistribution[i];
292	}
293
294
295	/**
296	* The TSC test driver.
297	*
298	* @param cLoops Number of test iterations.
299	* @param cSecs The number of seconds per iteration.
300	* @param uVerbosity How noisy we should be.
301	* @param iMinHistory The threshold for big gap history.
302	*/
303	static void bs3Timing1_Tsc_Driver(unsigned cLoops, unsigned cSecs, unsigned uVerbosity, unsigned iMinHistory)
304	{
305	unsigned iLoop;
306
307	#if 1
308	/*
309	* Verify that the first/last bit in U64 works (didn't).
310	*/
311	iLoop = ASMBitLastSetU64( UINT64_C(0x1000100010001000)); if (iLoop != 61) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
312	iLoop = ASMBitFirstSetU64(UINT64_C(0x1000100010001000)); if (iLoop != 13) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
313	iLoop = ASMBitLastSetU64( UINT64_C(0x000ffff000000000)); if (iLoop != 52) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
314	iLoop = ASMBitFirstSetU64(UINT64_C(0x000ffff000000000)); if (iLoop != 37) Bs3TestFailedF("%d: iLoop=%d\n", __LINE__, iLoop);
315	#endif
316
317	/*
318	* Do the work.
319	*/
320	Bs3TestPrintf("Running %u loops, %u second%s each...\n", cLoops, cSecs, cSecs != 1 ? "s" : "");
321	for (iLoop = 1; iLoop <= cLoops; iLoop++)
322	bs3Timing1_Tsc_One(iLoop, cSecs, uVerbosity, iMinHistory);
323
324	/*
325	* Report the total.
326	*/
327	Bs3TestPrintf("Total:\n");
328	bs3Timing1_PrintResult(&g_TotalResult, iLoop, uVerbosity + 1);
329
330	/*
331	* Dump the large gap history, if any.
332	*/
333	if (g_fBigHistoryWrapped \|\| g_iBigHistory > 0)
334	{
335	uint32_t const iFirst = g_fBigHistoryWrapped ? g_iBigHistory : 0;
336	uint32_t const iEnd = g_iBigHistory;
337	uint64_t uTscPrev = g_aBigHistory[iFirst].uTsc;
338	uint32_t i = iFirst;
339	Bs3TestPrintf("Big gap history (TSC, prev delta, test delta\|level):\n");
340	do
341	{
342	Bs3TestPrintf(" %'RU64: %'14RU64 - %'14RU64\|%u\n", g_aBigHistory[i].uTsc, g_aBigHistory[i].uTsc - uTscPrev,
343	g_aBigHistory[i].cTicksDelta, ASMBitLastSetU64(g_aBigHistory[i].cTicksDelta));
344	uTscPrev = g_aBigHistory[i].uTsc;
345	if (++i >= RT_ELEMENTS(g_aBigHistory))
346	i = 0;
347	} while (i != iEnd);
348	}
349	else
350	Bs3TestPrintf("No big gap history.\n");
351	}
352
353
354	#ifndef STANDALONE_EXECUTABLE
355	BS3_DECL(void) bs3Timing1_Tsc_pe32(void)
356	{
357	Bs3TestPrintf("bs3Timing1_Tsc_pe32\n");
358	bs3Timing1_Tsc_Driver(60, 10 /sec/, 1 /uVerbosity/, 17);
359	}
360	#endif
361
362	/* P.S. don't forget: VBoxManage setextradata bs3-timing-1 VBoxInternal/Devices/VMMDev/0/Config/TestingEnabled 1 */
363

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