1 /*
2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jfr/recorder/service/jfrMemorySizer.hpp"
27 #include "runtime/os.hpp"
28
29 const julong MAX_ADJUSTED_GLOBAL_BUFFER_SIZE = 1 * M;
30 const julong MIN_ADJUSTED_GLOBAL_BUFFER_SIZE_CUTOFF = 512 * K;
31 const julong MIN_GLOBAL_BUFFER_SIZE = 64 * K;
32 // implies at least 2 * MIN_GLOBAL_BUFFER SIZE
33 const julong MIN_BUFFER_COUNT = 2;
34 // MAX global buffer count open ended
35 const julong DEFAULT_BUFFER_COUNT = 20;
36 // MAX thread local buffer size == size of a single global buffer (runtime determined)
37 // DEFAULT thread local buffer size = 2 * os page size (runtime determined)
38 const julong MIN_THREAD_BUFFER_SIZE = 4 * K;
39 const julong MIN_MEMORY_SIZE = 1 * M;
40 const julong DEFAULT_MEMORY_SIZE = 10 * M;
41
42 //
43 // In pages:
44 //
45 // units = total_pages / per_unit_pages
46 //
47 static julong div_pages(julong& total_pages, julong& per_unit_pages) {
48 assert(total_pages > 0, "invariant");
49 assert(per_unit_pages > 0, "invariant");
50 assert(total_pages >= per_unit_pages, "invariant");
51
52 const julong units = total_pages / per_unit_pages;
53 const julong rem = total_pages % per_unit_pages;
54
55 assert(units > 0, "invariant");
56
57 if (rem > 0) {
58 total_pages -= rem % units;
59 per_unit_pages += rem / units;
60 }
61
62 assert(per_unit_pages > 0, "invariant");
63 assert(total_pages % units == 0, "invariant");
64 assert(units * per_unit_pages == total_pages, "invariant");
65 assert(units == total_pages / per_unit_pages, "invariant");
66
67 return units;
68 }
69
70 static void page_size_align_up(julong& value) {
71 static const julong alignment = os::vm_page_size() - 1;
72 value = (value + alignment) & ~alignment;
73 }
74
75 //
76 // In bytes:
77 // units = total_bytes / per_unit_bytes
78 //
79 static julong div_total_by_per_unit(julong& total_bytes, julong& per_unit_bytes) {
80 assert(total_bytes > 0, "invariant");
81 assert(per_unit_bytes > 0, "invariant");
82 assert(total_bytes >= per_unit_bytes, "invariant");
83
84 page_size_align_up(total_bytes);
85 assert(total_bytes % os::vm_page_size() == 0, "invariant");
86 julong total_pages = total_bytes / os::vm_page_size();
87
88 page_size_align_up(per_unit_bytes);
89 assert(per_unit_bytes % os::vm_page_size() == 0, "invariant");
90 julong per_unit_pages = per_unit_bytes / os::vm_page_size();
91
92 const julong units = div_pages(total_pages, per_unit_pages);
93 assert(units > 0, "invariant");
94
95 total_bytes = total_pages * os::vm_page_size();
96 per_unit_bytes = per_unit_pages * os::vm_page_size();
97
98 assert(per_unit_bytes > 0, "invariant");
99 assert(total_bytes / per_unit_bytes == units, "invariant");
100
101 return units;
102 }
103
104 //
105 // per_unit_bytes = total_bytes / units
106 //
107 static julong div_total_by_units(julong& total_bytes, julong& units) {
108 page_size_align_up(total_bytes);
109 assert(total_bytes % os::vm_page_size() == 0, "invariant");
110 julong total_pages = total_bytes / os::vm_page_size();
111 assert(units > 0, "invariant");
112
113 julong per_unit_pages = total_pages <= units ? 1 : total_pages / units;
114 units = div_pages(total_pages, per_unit_pages);
115
116 julong per_unit_bytes = per_unit_pages * os::vm_page_size();
117 assert(per_unit_bytes % os::vm_page_size() == 0, "invariant");
118
119 total_bytes = total_pages * os::vm_page_size();
120 assert(total_bytes % os::vm_page_size() == 0, "invariant");
121
122 assert(total_bytes % units == 0, "invariant");
123 assert(total_bytes / units == per_unit_bytes, "invariant");
124 assert(units * per_unit_bytes == total_bytes, "invariant");
125
126 return per_unit_bytes;
127 }
128
129 //
130 // total_bytes = per_unit_bytes * units;
131 //
132 static julong multiply(julong& per_unit_bytes, julong& units) {
133 page_size_align_up(per_unit_bytes);
134 assert(per_unit_bytes % os::vm_page_size() == 0, "invariant");
135 assert(units > 0, "invariant");
136
137 julong total_bytes = per_unit_bytes * units;
138 assert(total_bytes % os::vm_page_size() == 0, "invariant");
139
140 assert(total_bytes % units == 0, "invariant");
141 assert(total_bytes / units == per_unit_bytes, "invariant");
142 assert(units * per_unit_bytes == total_bytes, "invariant");
143
144 return total_bytes;
145 }
146
147 // Total_bytes is explicitly set.
148 //
149 // Deduce other parameters by delegating to a sizing policy
150 template <typename SizingPolicy>
151 static julong adjust(JfrMemoryOptions* options) {
152 page_size_align_up(options->memory_size);
153 assert(options->memory_size % os::vm_page_size() == 0, "invariant");
154 julong total_pages = options->memory_size / os::vm_page_size();
155 assert(options->buffer_count > 0, "invariant");
156 julong per_unit_pages = total_pages / options->buffer_count;
157 page_size_align_up(options->thread_buffer_size);
158 assert(options->thread_buffer_size % os::vm_page_size() == 0, "invariant");
159 julong thread_buffer_pages = options->thread_buffer_size / os::vm_page_size();
160
161 SizingPolicy::adjust(total_pages, per_unit_pages, options->buffer_count, thread_buffer_pages, options->thread_buffer_size_configured);
162 assert(options->buffer_count * per_unit_pages == total_pages, "invariant");
163
164 const julong per_unit_bytes = per_unit_pages * os::vm_page_size();
165 options->memory_size = total_pages * os::vm_page_size();
166 options->thread_buffer_size = thread_buffer_pages * os::vm_page_size();
167
168 assert(options->memory_size % options->buffer_count == 0, "invariant");
169 assert(options->memory_size / options->buffer_count == per_unit_bytes, "invariant");
170 assert(options->buffer_count * per_unit_bytes == options->memory_size, "invariant");
171 assert(per_unit_bytes >= options->thread_buffer_size, "invariant");
172 return per_unit_bytes;
173 }
174
175 static void align_buffer_size(julong& buffer_size_in_pages, julong max_size_pages, julong min_size_pages, bool sizeup = false) {
176 buffer_size_in_pages = MIN2(buffer_size_in_pages, max_size_pages);
177 buffer_size_in_pages = MAX2(buffer_size_in_pages, min_size_pages);
178 size_t multiples = 0;
179 if (buffer_size_in_pages < max_size_pages) {
180 while (buffer_size_in_pages >=
181 (min_size_pages << (multiples + (sizeup ? 0 : 1)))) {
182 ++multiples;
183 }
184 buffer_size_in_pages = min_size_pages << multiples;
185 }
186 assert(buffer_size_in_pages >= min_size_pages && buffer_size_in_pages <= max_size_pages, "invariant");
187 }
188
189 static void adjust_buffer_size_to_total_memory_size(julong& total_pages, julong& buffer_size_pages) {
190 static const julong max_buffer_size_pages = MAX_ADJUSTED_GLOBAL_BUFFER_SIZE / os::vm_page_size();
191 // If memory size is less than DEFAULT_MEMORY_SIZE,
192 // the adjustment algorithm can decrease the size of the global buffer
193 // all the way down to the MIN_GLOBAL_BUFFER_SIZE (taking embedded use case in account).
194 // If memory size is larger than DEFAULT_MEMORY_SIZE, the lowest size of
195 // a global buffer will be the size of MIN_ADJUSTED_GLOBAL_BUFFER_SIZE_CUTOFF
196 static const julong min_buffer_size_pages =
197 total_pages * os::vm_page_size() < DEFAULT_MEMORY_SIZE ?
198 MIN_GLOBAL_BUFFER_SIZE / os::vm_page_size() :
199 MIN_ADJUSTED_GLOBAL_BUFFER_SIZE_CUTOFF / os::vm_page_size();
200
201 align_buffer_size(buffer_size_pages, max_buffer_size_pages, min_buffer_size_pages);
202 assert(buffer_size_pages % min_buffer_size_pages == 0, "invariant");
203
204 julong remainder = total_pages % buffer_size_pages;
205 while (remainder >= (buffer_size_pages >> 1)) {
206 if (buffer_size_pages <= min_buffer_size_pages) {
207 break;
208 }
209 buffer_size_pages >>= 1;
210 remainder = total_pages % buffer_size_pages;
211 }
212 }
213
214 // Sizing policy class
215 class ScaleOutAdjuster : public AllStatic {
216 public:
217 static void adjust(julong& total_pages,
218 julong& buffer_size_pages,
219 julong& buffer_count,
220 julong& thread_buffer_size_pages,
221 bool is_thread_buffer_size_set) {
222 assert(buffer_count > 0, "invariant");
223 adjust_buffer_size_to_total_memory_size(total_pages, buffer_size_pages);
224 assert(buffer_size_pages * os::vm_page_size() >= MIN_GLOBAL_BUFFER_SIZE, "invariant");
225 assert((buffer_size_pages * os::vm_page_size()) % MIN_GLOBAL_BUFFER_SIZE == 0, "invariant");
226 if (is_thread_buffer_size_set) {
227 if (thread_buffer_size_pages > buffer_size_pages) {
228 buffer_size_pages = thread_buffer_size_pages;
229 }
230 }
231 // and with this information, calculate what the new buffer count will be
232 buffer_count = div_pages(total_pages, buffer_size_pages);
233 }
234 };
235
236 static void memory_and_thread_buffer_size(JfrMemoryOptions* options) {
237 assert(options->memory_size_configured, "invariant");
238 assert(!options->buffer_count_configured, "invariant");
239 assert(!options->global_buffer_size_configured, "invariant");
240 // here the only thing specified is the overall total memory size
241 // we can and will apply some sizing heuristics to derive both
242 // the size of an individual global buffer and by implication the number of global
243 // buffers to use. Starting values for buffer count and global_buffer_size
244 // will be the defaults.
245 options->global_buffer_size = adjust<ScaleOutAdjuster>(options);
246 }
247
248 static void memory_size_and_buffer_count(JfrMemoryOptions* options) {
249 assert(options->memory_size_configured, "invariant");
250 assert(!options->global_buffer_size_configured, "invariant");
251 assert(!options->thread_buffer_size_configured, "invariant");
252 assert(options->buffer_count_configured, "invariant");
253 options->global_buffer_size = div_total_by_units(options->memory_size, options->buffer_count);
254 }
255
256 static void memory_size_and_global_buffer_size(JfrMemoryOptions* options) {
257 assert(options->memory_size_configured, "invariant");
258 assert(options->global_buffer_size_configured, "invariant");
259 assert(!options->buffer_count_configured, "invariant");
260 page_size_align_up(options->thread_buffer_size);
261 options->buffer_count = div_total_by_per_unit(options->memory_size, options->global_buffer_size);
262 if (options->thread_buffer_size > options->global_buffer_size) {
263 options->global_buffer_size = options->thread_buffer_size;
264 options->buffer_count = div_total_by_per_unit(options->memory_size, options->global_buffer_size);
265 }
266 assert(options->global_buffer_size >= options->thread_buffer_size, "invariant");
267 }
268
269 static bool is_ambiguous(const JfrMemoryOptions* options) {
270 assert(options->memory_size_configured, "invariant");
271 assert(options->global_buffer_size_configured, "invariant");
272 assert(options->buffer_count_configured, "invariant");
273 assert(options->thread_buffer_size <= options->global_buffer_size, "invariant");
274 // This can cause an ambiguous situation because all three parameters are explicitly set.
275 return options->global_buffer_size * options->buffer_count != options->memory_size;
276 }
277
278 static void all_options_set(JfrMemoryOptions* options) {
279 options->buffer_count = div_total_by_per_unit(options->memory_size, options->global_buffer_size);
280 page_size_align_up(options->thread_buffer_size);
281 if (options->thread_buffer_size > options->global_buffer_size) {
282 options->global_buffer_size = options->thread_buffer_size;
283 options->buffer_count = div_total_by_per_unit(options->memory_size, options->global_buffer_size);
284 }
285 assert(options->global_buffer_size >= options->thread_buffer_size, "invariant");
286 assert(options->memory_size / options->global_buffer_size == options->buffer_count, "invariant");
287 assert(options->memory_size % options->global_buffer_size == 0, "invariant");
288 }
289
290 static void global_buffer_size(JfrMemoryOptions* options) {
291 assert(!options->memory_size_configured, "invariant");
292 page_size_align_up(options->thread_buffer_size);
293 if (options->thread_buffer_size > options->global_buffer_size) {
294 options->global_buffer_size = options->thread_buffer_size;
295 }
296 options->memory_size = multiply(options->global_buffer_size, options->buffer_count);
297 assert(options->global_buffer_size >= options->thread_buffer_size, "invariant");
298 }
299
300 static void thread_buffer_size(JfrMemoryOptions* options) {
301 assert(!options->global_buffer_size_configured, "invariant");
302 assert(options->thread_buffer_size_configured, "invariant");
303 page_size_align_up(options->thread_buffer_size);
304 options->global_buffer_size = div_total_by_units(options->memory_size, options->buffer_count);
305 if (options->thread_buffer_size > options->global_buffer_size) {
306 options->global_buffer_size = options->thread_buffer_size;
307 options->buffer_count = div_total_by_per_unit(options->memory_size, options->global_buffer_size);
308 }
309 assert(options->global_buffer_size >= options->thread_buffer_size, "invariant");
310 }
311
312 static void default_size(const JfrMemoryOptions* options) {
313 // no memory options explicitly set
314 // default values already statically adjusted
315 assert(!options->thread_buffer_size_configured, "invariant");
316 assert(!options->memory_size_configured, "invariant");
317 assert(!options->buffer_count_configured, "invarinat");
318 assert(!options->global_buffer_size_configured, "invariant");
319 }
320
321 #ifdef ASSERT
322 static void assert_post_condition(const JfrMemoryOptions* options) {
323 assert(options->memory_size % os::vm_page_size() == 0, "invariant");
324 assert(options->global_buffer_size % os::vm_page_size() == 0, "invariant");
325 assert(options->thread_buffer_size % os::vm_page_size() == 0, "invariant");
326 assert(options->buffer_count > 0, "invariant");
327 }
328 #endif
329
330 // MEMORY SIZING ALGORITHM
331
332 bool JfrMemorySizer::adjust_options(JfrMemoryOptions* options) {
333 assert(options != NULL, "invariant");
334
335 enum MemoryOptions {
336 MEMORY_SIZE = 1,
337 GLOBAL_BUFFER_SIZE = 2,
338 GLOBAL_BUFFER_COUNT = 4,
339 THREAD_BUFFER_SIZE = 8
340 };
341
342 // LEGEND
343 //
344 // M = "memorysize" option
345 // G = "globalbuffersize" option
346 // C = "numglobalbuffers" option
347 // T = "threadbuffersize" option
348 //
349 // The memory options comprise an n-set (a 4-set) = { M, G, C, T }
350 //
351 // Number of r-subsets = 5 (0, 1, 2, 3, 4) (including null set)
352 //
353 // Unordered selection:
354 //
355 // C(4, 0) = {} = NULL set = 1
356 // C(4, 1) = { (M), (G), (C), (T) } = 4
357 // C(4, 2) = { (M, G), (M, C), (M, T), (G, C), (G, T), (C, T) } = 6
358 // C(4, 3) = { (M, G, C), (M, G, T), (M, C, T), (G, C, T) } = 4
359 // C(4, 4) = { (M, G, C, T) } = 1
360 //
361 // in shorter terms: P({ M, G, C, T}) = 16
362 //
363 #define MG (MEMORY_SIZE | GLOBAL_BUFFER_SIZE)
364 #define MC (MEMORY_SIZE | GLOBAL_BUFFER_COUNT)
365 #define MT (MEMORY_SIZE | THREAD_BUFFER_SIZE)
366 #define MGC (MG | GLOBAL_BUFFER_COUNT)
367 #define MGT (MG | THREAD_BUFFER_SIZE)
368 #define MCT (MC | THREAD_BUFFER_SIZE)
369 #define MGCT (MGC | THREAD_BUFFER_SIZE)
370 #define GC (GLOBAL_BUFFER_SIZE | GLOBAL_BUFFER_COUNT)
371 #define GT (GLOBAL_BUFFER_SIZE | THREAD_BUFFER_SIZE)
372 #define GCT (GC | THREAD_BUFFER_SIZE)
373 #define CT (GLOBAL_BUFFER_COUNT | THREAD_BUFFER_SIZE)
374
375 int set_of_options = 0;
376
377 if (options->memory_size_configured) {
378 set_of_options |= MEMORY_SIZE;
379 }
380 if (options->global_buffer_size_configured) {
381 set_of_options |= GLOBAL_BUFFER_SIZE;
382 }
383 if (options->buffer_count_configured) {
384 set_of_options |= GLOBAL_BUFFER_COUNT;
385 }
386 if (options->thread_buffer_size_configured) {
387 set_of_options |= THREAD_BUFFER_SIZE;
388 }
389
390 switch (set_of_options) {
391 case MT:
392 case MEMORY_SIZE:
393 memory_and_thread_buffer_size(options);
394 break;
395 case MC:
396 memory_size_and_buffer_count(options);
397 break;
398 case MGT:
399 assert(options->thread_buffer_size_configured, "invariant");
400 case MG:
401 memory_size_and_global_buffer_size(options);
402 break;
403 case MGC:
404 case MGCT:
405 if (is_ambiguous(options)) {
406 // Let the user resolve the ambiguity by bailing.
407 return false;
408 }
409 all_options_set(options);
410 break;
411 case GCT:
412 assert(options->buffer_count_configured, "invariant");
413 assert(options->thread_buffer_size_configured, "invariant");
414 case GC:
415 assert(options->global_buffer_size_configured, "invariant");
416 case GT:
417 case GLOBAL_BUFFER_COUNT:
418 case GLOBAL_BUFFER_SIZE:
419 global_buffer_size(options);
420 break;
421 case MCT:
422 assert(options->memory_size_configured, "invariant");
423 case CT:
424 assert(options->buffer_count_configured, "invariant");
425 case THREAD_BUFFER_SIZE:
426 thread_buffer_size(options);
427 break;
428 default:
429 default_size(options);
430 }
431 DEBUG_ONLY(assert_post_condition(options);)
432 return true;
433 }