blob: 99513e1160e518d322f6d0ce0f346e6da9fcbbf0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/kernel/profile.c
3 * Simple profiling. Manages a direct-mapped profile hit count buffer,
4 * with configurable resolution, support for restricting the cpus on
5 * which profiling is done, and switching between cpu time and
6 * schedule() calls via kernel command line parameters passed at boot.
7 *
8 * Scheduler profiling support, Arjan van de Ven and Ingo Molnar,
9 * Red Hat, July 2004
10 * Consolidation of architecture support code for profiling,
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +010011 * Nadia Yvette Chambers, Oracle, July 2004
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 * Amortized hit count accounting via per-cpu open-addressed hashtables
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +010013 * to resolve timer interrupt livelocks, Nadia Yvette Chambers,
14 * Oracle, 2004
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 */
16
Paul Gortmaker9984de12011-05-23 14:51:41 -040017#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/profile.h>
19#include <linux/bootmem.h>
20#include <linux/notifier.h>
21#include <linux/mm.h>
22#include <linux/cpumask.h>
23#include <linux/cpu.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/highmem.h>
Arjan van de Ven97d1f152006-03-23 03:00:24 -080025#include <linux/mutex.h>
Dave Hansen22b8ce92008-10-15 22:01:46 -070026#include <linux/slab.h>
27#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <asm/sections.h>
David Howells7d12e782006-10-05 14:55:46 +010029#include <asm/irq_regs.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040030#include <asm/ptrace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32struct profile_hit {
33 u32 pc, hits;
34};
35#define PROFILE_GRPSHIFT 3
36#define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT)
37#define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit))
38#define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ)
39
Linus Torvalds1da177e2005-04-16 15:20:36 -070040static atomic_t *prof_buffer;
41static unsigned long prof_len, prof_shift;
Ingo Molnar07031e12007-01-10 23:15:38 -080042
Ingo Molnarece8a682006-12-06 20:37:24 -080043int prof_on __read_mostly;
Ingo Molnar07031e12007-01-10 23:15:38 -080044EXPORT_SYMBOL_GPL(prof_on);
45
Rusty Russellc309b912009-01-01 10:12:27 +103046static cpumask_var_t prof_cpu_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#ifdef CONFIG_SMP
48static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);
49static DEFINE_PER_CPU(int, cpu_profile_flip);
Arjan van de Ven97d1f152006-03-23 03:00:24 -080050static DEFINE_MUTEX(profile_flip_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#endif /* CONFIG_SMP */
52
Dave Hansen22b8ce92008-10-15 22:01:46 -070053int profile_setup(char *str)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054{
Fabian Frederickf3da64d2014-06-06 14:37:30 -070055 static const char schedstr[] = "schedule";
56 static const char sleepstr[] = "sleep";
57 static const char kvmstr[] = "kvm";
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 int par;
59
Ingo Molnarece8a682006-12-06 20:37:24 -080060 if (!strncmp(str, sleepstr, strlen(sleepstr))) {
Mel Gormanb3da2a72007-10-24 18:23:50 +020061#ifdef CONFIG_SCHEDSTATS
Ingo Molnarece8a682006-12-06 20:37:24 -080062 prof_on = SLEEP_PROFILING;
63 if (str[strlen(sleepstr)] == ',')
64 str += strlen(sleepstr) + 1;
65 if (get_option(&str, &par))
66 prof_shift = par;
Fabian Frederickaba871f2014-06-06 14:37:29 -070067 pr_info("kernel sleep profiling enabled (shift: %ld)\n",
Ingo Molnarece8a682006-12-06 20:37:24 -080068 prof_shift);
Mel Gormanb3da2a72007-10-24 18:23:50 +020069#else
Fabian Frederickaba871f2014-06-06 14:37:29 -070070 pr_warn("kernel sleep profiling requires CONFIG_SCHEDSTATS\n");
Mel Gormanb3da2a72007-10-24 18:23:50 +020071#endif /* CONFIG_SCHEDSTATS */
Ingo Molnara75acf82007-01-05 16:36:29 -080072 } else if (!strncmp(str, schedstr, strlen(schedstr))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 prof_on = SCHED_PROFILING;
William Lee Irwin IIIdfaa9c92005-05-16 21:53:58 -070074 if (str[strlen(schedstr)] == ',')
75 str += strlen(schedstr) + 1;
76 if (get_option(&str, &par))
77 prof_shift = par;
Fabian Frederickaba871f2014-06-06 14:37:29 -070078 pr_info("kernel schedule profiling enabled (shift: %ld)\n",
William Lee Irwin IIIdfaa9c92005-05-16 21:53:58 -070079 prof_shift);
Ingo Molnar07031e12007-01-10 23:15:38 -080080 } else if (!strncmp(str, kvmstr, strlen(kvmstr))) {
81 prof_on = KVM_PROFILING;
82 if (str[strlen(kvmstr)] == ',')
83 str += strlen(kvmstr) + 1;
84 if (get_option(&str, &par))
85 prof_shift = par;
Fabian Frederickaba871f2014-06-06 14:37:29 -070086 pr_info("kernel KVM profiling enabled (shift: %ld)\n",
Ingo Molnar07031e12007-01-10 23:15:38 -080087 prof_shift);
William Lee Irwin IIIdfaa9c92005-05-16 21:53:58 -070088 } else if (get_option(&str, &par)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 prof_shift = par;
90 prof_on = CPU_PROFILING;
Fabian Frederickaba871f2014-06-06 14:37:29 -070091 pr_info("kernel profiling enabled (shift: %ld)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 prof_shift);
93 }
94 return 1;
95}
96__setup("profile=", profile_setup);
97
98
Paul Mundtce05fcc2008-10-29 14:01:07 -070099int __ref profile_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100{
Dave Hansen22b8ce92008-10-15 22:01:46 -0700101 int buffer_bytes;
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100102 if (!prof_on)
Dave Hansen22b8ce92008-10-15 22:01:46 -0700103 return 0;
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100104
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 /* only text is profiled */
106 prof_len = (_etext - _stext) >> prof_shift;
Dave Hansen22b8ce92008-10-15 22:01:46 -0700107 buffer_bytes = prof_len*sizeof(atomic_t);
Dave Hansen22b8ce92008-10-15 22:01:46 -0700108
Rusty Russellc309b912009-01-01 10:12:27 +1030109 if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL))
110 return -ENOMEM;
111
Hugh Dickinsacd89572009-02-09 19:20:50 +0000112 cpumask_copy(prof_cpu_mask, cpu_possible_mask);
113
Mel Gormanb62f4952009-07-29 15:04:09 -0700114 prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN);
Dave Hansen22b8ce92008-10-15 22:01:46 -0700115 if (prof_buffer)
116 return 0;
117
Mel Gormanb62f4952009-07-29 15:04:09 -0700118 prof_buffer = alloc_pages_exact(buffer_bytes,
119 GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN);
Dave Hansen22b8ce92008-10-15 22:01:46 -0700120 if (prof_buffer)
121 return 0;
122
Jesper Juhl559fa6e2010-10-30 21:56:26 +0200123 prof_buffer = vzalloc(buffer_bytes);
124 if (prof_buffer)
Dave Hansen22b8ce92008-10-15 22:01:46 -0700125 return 0;
126
Rusty Russellc309b912009-01-01 10:12:27 +1030127 free_cpumask_var(prof_cpu_mask);
Dave Hansen22b8ce92008-10-15 22:01:46 -0700128 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129}
130
131/* Profile event notifications */
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100132
Alan Sterne041c682006-03-27 01:16:30 -0800133static BLOCKING_NOTIFIER_HEAD(task_exit_notifier);
134static ATOMIC_NOTIFIER_HEAD(task_free_notifier);
135static BLOCKING_NOTIFIER_HEAD(munmap_notifier);
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100136
137void profile_task_exit(struct task_struct *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{
Alan Sterne041c682006-03-27 01:16:30 -0800139 blocking_notifier_call_chain(&task_exit_notifier, 0, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140}
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100141
142int profile_handoff_task(struct task_struct *task)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
144 int ret;
Alan Sterne041c682006-03-27 01:16:30 -0800145 ret = atomic_notifier_call_chain(&task_free_notifier, 0, task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 return (ret == NOTIFY_OK) ? 1 : 0;
147}
148
149void profile_munmap(unsigned long addr)
150{
Alan Sterne041c682006-03-27 01:16:30 -0800151 blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100154int task_handoff_register(struct notifier_block *n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
Alan Sterne041c682006-03-27 01:16:30 -0800156 return atomic_notifier_chain_register(&task_free_notifier, n);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157}
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100158EXPORT_SYMBOL_GPL(task_handoff_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100160int task_handoff_unregister(struct notifier_block *n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161{
Alan Sterne041c682006-03-27 01:16:30 -0800162 return atomic_notifier_chain_unregister(&task_free_notifier, n);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100164EXPORT_SYMBOL_GPL(task_handoff_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100166int profile_event_register(enum profile_type type, struct notifier_block *n)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167{
168 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 switch (type) {
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100171 case PROFILE_TASK_EXIT:
172 err = blocking_notifier_chain_register(
173 &task_exit_notifier, n);
174 break;
175 case PROFILE_MUNMAP:
176 err = blocking_notifier_chain_register(
177 &munmap_notifier, n);
178 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 }
180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 return err;
182}
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100183EXPORT_SYMBOL_GPL(profile_event_register);
184
185int profile_event_unregister(enum profile_type type, struct notifier_block *n)
186{
187 int err = -EINVAL;
188
189 switch (type) {
190 case PROFILE_TASK_EXIT:
191 err = blocking_notifier_chain_unregister(
192 &task_exit_notifier, n);
193 break;
194 case PROFILE_MUNMAP:
195 err = blocking_notifier_chain_unregister(
196 &munmap_notifier, n);
197 break;
198 }
199
200 return err;
201}
202EXPORT_SYMBOL_GPL(profile_event_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204#ifdef CONFIG_SMP
205/*
206 * Each cpu has a pair of open-addressed hashtables for pending
207 * profile hits. read_profile() IPI's all cpus to request them
208 * to flip buffers and flushes their contents to prof_buffer itself.
209 * Flip requests are serialized by the profile_flip_mutex. The sole
210 * use of having a second hashtable is for avoiding cacheline
211 * contention that would otherwise happen during flushes of pending
212 * profile hits required for the accuracy of reported profile hits
213 * and so resurrect the interrupt livelock issue.
214 *
215 * The open-addressed hashtables are indexed by profile buffer slot
216 * and hold the number of pending hits to that profile buffer slot on
217 * a cpu in an entry. When the hashtable overflows, all pending hits
218 * are accounted to their corresponding profile buffer slots with
219 * atomic_add() and the hashtable emptied. As numerous pending hits
220 * may be accounted to a profile buffer slot in a hashtable entry,
221 * this amortizes a number of atomic profile buffer increments likely
222 * to be far larger than the number of entries in the hashtable,
223 * particularly given that the number of distinct profile buffer
224 * positions to which hits are accounted during short intervals (e.g.
225 * several seconds) is usually very small. Exclusion from buffer
226 * flipping is provided by interrupt disablement (note that for
Ingo Molnarece8a682006-12-06 20:37:24 -0800227 * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from
228 * process context).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 * The hash function is meant to be lightweight as opposed to strong,
230 * and was vaguely inspired by ppc64 firmware-supported inverted
231 * pagetable hash functions, but uses a full hashtable full of finite
232 * collision chains, not just pairs of them.
233 *
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +0100234 * -- nyc
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 */
236static void __profile_flip_buffers(void *unused)
237{
238 int cpu = smp_processor_id();
239
240 per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu);
241}
242
243static void profile_flip_buffers(void)
244{
245 int i, j, cpu;
246
Arjan van de Ven97d1f152006-03-23 03:00:24 -0800247 mutex_lock(&profile_flip_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 j = per_cpu(cpu_profile_flip, get_cpu());
249 put_cpu();
Jens Axboe15c8b6c2008-05-09 09:39:44 +0200250 on_each_cpu(__profile_flip_buffers, NULL, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 for_each_online_cpu(cpu) {
252 struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j];
253 for (i = 0; i < NR_PROFILE_HIT; ++i) {
254 if (!hits[i].hits) {
255 if (hits[i].pc)
256 hits[i].pc = 0;
257 continue;
258 }
259 atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]);
260 hits[i].hits = hits[i].pc = 0;
261 }
262 }
Arjan van de Ven97d1f152006-03-23 03:00:24 -0800263 mutex_unlock(&profile_flip_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264}
265
266static void profile_discard_flip_buffers(void)
267{
268 int i, cpu;
269
Arjan van de Ven97d1f152006-03-23 03:00:24 -0800270 mutex_lock(&profile_flip_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 i = per_cpu(cpu_profile_flip, get_cpu());
272 put_cpu();
Jens Axboe15c8b6c2008-05-09 09:39:44 +0200273 on_each_cpu(__profile_flip_buffers, NULL, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 for_each_online_cpu(cpu) {
275 struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i];
276 memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit));
277 }
Arjan van de Ven97d1f152006-03-23 03:00:24 -0800278 mutex_unlock(&profile_flip_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279}
280
Rakib Mullick6f7bd762011-05-26 16:26:00 -0700281static void do_profile_hits(int type, void *__pc, unsigned int nr_hits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282{
283 unsigned long primary, secondary, flags, pc = (unsigned long)__pc;
284 int i, j, cpu;
285 struct profile_hit *hits;
286
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1);
288 i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT;
289 secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT;
290 cpu = get_cpu();
291 hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)];
292 if (!hits) {
293 put_cpu();
294 return;
295 }
Ingo Molnarece8a682006-12-06 20:37:24 -0800296 /*
297 * We buffer the global profiler buffer into a per-CPU
298 * queue and thus reduce the number of global (and possibly
299 * NUMA-alien) accesses. The write-queue is self-coalescing:
300 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 local_irq_save(flags);
302 do {
303 for (j = 0; j < PROFILE_GRPSZ; ++j) {
304 if (hits[i + j].pc == pc) {
Ingo Molnarece8a682006-12-06 20:37:24 -0800305 hits[i + j].hits += nr_hits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 goto out;
307 } else if (!hits[i + j].hits) {
308 hits[i + j].pc = pc;
Ingo Molnarece8a682006-12-06 20:37:24 -0800309 hits[i + j].hits = nr_hits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 goto out;
311 }
312 }
313 i = (i + secondary) & (NR_PROFILE_HIT - 1);
314 } while (i != primary);
Ingo Molnarece8a682006-12-06 20:37:24 -0800315
316 /*
317 * Add the current hit(s) and flush the write-queue out
318 * to the global buffer:
319 */
320 atomic_add(nr_hits, &prof_buffer[pc]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 for (i = 0; i < NR_PROFILE_HIT; ++i) {
322 atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]);
323 hits[i].pc = hits[i].hits = 0;
324 }
325out:
326 local_irq_restore(flags);
327 put_cpu();
328}
329
Paul Gortmaker0db06282013-06-19 14:53:51 -0400330static int profile_cpu_callback(struct notifier_block *info,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 unsigned long action, void *__cpu)
332{
333 int node, cpu = (unsigned long)__cpu;
334 struct page *page;
335
336 switch (action) {
337 case CPU_UP_PREPARE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700338 case CPU_UP_PREPARE_FROZEN:
Lee Schermerhorn3dd6b5f2010-05-26 14:45:04 -0700339 node = cpu_to_mem(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 per_cpu(cpu_profile_flip, cpu) = 0;
341 if (!per_cpu(cpu_profile_hits, cpu)[1]) {
Vlastimil Babka96db8002015-09-08 15:03:50 -0700342 page = __alloc_pages_node(node,
Christoph Lameter4199cfa2007-10-16 01:25:34 -0700343 GFP_KERNEL | __GFP_ZERO,
Christoph Lameterfbd98162006-09-25 23:31:45 -0700344 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 if (!page)
Akinobu Mita80b51842010-05-26 14:43:32 -0700346 return notifier_from_errno(-ENOMEM);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 per_cpu(cpu_profile_hits, cpu)[1] = page_address(page);
348 }
349 if (!per_cpu(cpu_profile_hits, cpu)[0]) {
Vlastimil Babka96db8002015-09-08 15:03:50 -0700350 page = __alloc_pages_node(node,
Christoph Lameter4199cfa2007-10-16 01:25:34 -0700351 GFP_KERNEL | __GFP_ZERO,
Christoph Lameterfbd98162006-09-25 23:31:45 -0700352 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 if (!page)
354 goto out_free;
355 per_cpu(cpu_profile_hits, cpu)[0] = page_address(page);
356 }
357 break;
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100358out_free:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
360 per_cpu(cpu_profile_hits, cpu)[1] = NULL;
361 __free_page(page);
Akinobu Mita80b51842010-05-26 14:43:32 -0700362 return notifier_from_errno(-ENOMEM);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 case CPU_ONLINE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700364 case CPU_ONLINE_FROZEN:
Rusty Russellc309b912009-01-01 10:12:27 +1030365 if (prof_cpu_mask != NULL)
366 cpumask_set_cpu(cpu, prof_cpu_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 break;
368 case CPU_UP_CANCELED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700369 case CPU_UP_CANCELED_FROZEN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -0700371 case CPU_DEAD_FROZEN:
Rusty Russellc309b912009-01-01 10:12:27 +1030372 if (prof_cpu_mask != NULL)
373 cpumask_clear_cpu(cpu, prof_cpu_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 if (per_cpu(cpu_profile_hits, cpu)[0]) {
375 page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
376 per_cpu(cpu_profile_hits, cpu)[0] = NULL;
377 __free_page(page);
378 }
379 if (per_cpu(cpu_profile_hits, cpu)[1]) {
380 page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
381 per_cpu(cpu_profile_hits, cpu)[1] = NULL;
382 __free_page(page);
383 }
384 break;
385 }
386 return NOTIFY_OK;
387}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388#else /* !CONFIG_SMP */
389#define profile_flip_buffers() do { } while (0)
390#define profile_discard_flip_buffers() do { } while (0)
Ingo Molnar023160672006-12-06 20:38:17 -0800391#define profile_cpu_callback NULL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
Rakib Mullick6f7bd762011-05-26 16:26:00 -0700393static void do_profile_hits(int type, void *__pc, unsigned int nr_hits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394{
395 unsigned long pc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift;
Ingo Molnarece8a682006-12-06 20:37:24 -0800397 atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398}
399#endif /* !CONFIG_SMP */
Rakib Mullick6f7bd762011-05-26 16:26:00 -0700400
401void profile_hits(int type, void *__pc, unsigned int nr_hits)
402{
403 if (prof_on != type || !prof_buffer)
404 return;
405 do_profile_hits(type, __pc, nr_hits);
406}
Andrew Mortonbbe1a59b2007-01-22 20:40:33 -0800407EXPORT_SYMBOL_GPL(profile_hits);
408
David Howells7d12e782006-10-05 14:55:46 +0100409void profile_tick(int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410{
David Howells7d12e782006-10-05 14:55:46 +0100411 struct pt_regs *regs = get_irq_regs();
412
Rusty Russellc309b912009-01-01 10:12:27 +1030413 if (!user_mode(regs) && prof_cpu_mask != NULL &&
414 cpumask_test_cpu(smp_processor_id(), prof_cpu_mask))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 profile_hit(type, (void *)profile_pc(regs));
416}
417
418#ifdef CONFIG_PROC_FS
419#include <linux/proc_fs.h>
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700420#include <linux/seq_file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421#include <asm/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700423static int prof_cpu_mask_proc_show(struct seq_file *m, void *v)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424{
Tejun Heoccbd59c2015-02-13 14:38:13 -0800425 seq_printf(m, "%*pb\n", cpumask_pr_args(prof_cpu_mask));
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700426 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427}
428
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700429static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430{
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700431 return single_open(file, prof_cpu_mask_proc_show, NULL);
432}
433
434static ssize_t prof_cpu_mask_proc_write(struct file *file,
435 const char __user *buffer, size_t count, loff_t *pos)
436{
Rusty Russellc309b912009-01-01 10:12:27 +1030437 cpumask_var_t new_value;
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700438 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
Rusty Russellc309b912009-01-01 10:12:27 +1030440 if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
441 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
Rusty Russellc309b912009-01-01 10:12:27 +1030443 err = cpumask_parse_user(buffer, count, new_value);
444 if (!err) {
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700445 cpumask_copy(prof_cpu_mask, new_value);
446 err = count;
Rusty Russellc309b912009-01-01 10:12:27 +1030447 }
448 free_cpumask_var(new_value);
449 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450}
451
Alexey Dobriyan583a22e2009-09-18 12:57:09 -0700452static const struct file_operations prof_cpu_mask_proc_fops = {
453 .open = prof_cpu_mask_proc_open,
454 .read = seq_read,
455 .llseek = seq_lseek,
456 .release = single_release,
457 .write = prof_cpu_mask_proc_write,
458};
459
Al Virofbd387a2013-04-01 20:48:34 -0400460void create_prof_cpu_mask(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 /* create /proc/irq/prof_cpu_mask */
Al Virofbd387a2013-04-01 20:48:34 -0400463 proc_create("irq/prof_cpu_mask", 0600, NULL, &prof_cpu_mask_proc_fops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464}
465
466/*
467 * This function accesses profiling information. The returned data is
468 * binary: the sampling step and the actual contents of the profile
469 * buffer. Use of the program readprofile is recommended in order to
470 * get meaningful info out of these data.
471 */
472static ssize_t
473read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos)
474{
475 unsigned long p = *ppos;
476 ssize_t read;
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100477 char *pnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 unsigned int sample_step = 1 << prof_shift;
479
480 profile_flip_buffers();
481 if (p >= (prof_len+1)*sizeof(unsigned int))
482 return 0;
483 if (count > (prof_len+1)*sizeof(unsigned int) - p)
484 count = (prof_len+1)*sizeof(unsigned int) - p;
485 read = 0;
486
487 while (p < sizeof(unsigned int) && count > 0) {
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100488 if (put_user(*((char *)(&sample_step)+p), buf))
Heiko Carstens064b0222006-12-06 20:36:37 -0800489 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 buf++; p++; count--; read++;
491 }
492 pnt = (char *)prof_buffer + p - sizeof(atomic_t);
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100493 if (copy_to_user(buf, (void *)pnt, count))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 return -EFAULT;
495 read += count;
496 *ppos += read;
497 return read;
498}
499
500/*
501 * Writing to /proc/profile resets the counters
502 *
503 * Writing a 'profiling multiplier' value into it also re-sets the profiling
504 * interrupt frequency, on architectures that support this.
505 */
506static ssize_t write_profile(struct file *file, const char __user *buf,
507 size_t count, loff_t *ppos)
508{
509#ifdef CONFIG_SMP
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100510 extern int setup_profiling_timer(unsigned int multiplier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511
512 if (count == sizeof(int)) {
513 unsigned int multiplier;
514
515 if (copy_from_user(&multiplier, buf, sizeof(int)))
516 return -EFAULT;
517
518 if (setup_profiling_timer(multiplier))
519 return -EINVAL;
520 }
521#endif
522 profile_discard_flip_buffers();
523 memset(prof_buffer, 0, prof_len * sizeof(atomic_t));
524 return count;
525}
526
Helge Deller15ad7cd2006-12-06 20:40:36 -0800527static const struct file_operations proc_profile_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 .read = read_profile,
529 .write = write_profile,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200530 .llseek = default_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531};
532
533#ifdef CONFIG_SMP
Andrew Morton60a51512008-11-18 22:20:10 -0800534static void profile_nop(void *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535{
536}
537
Dave Hansen22b8ce92008-10-15 22:01:46 -0700538static int create_hash_tables(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539{
540 int cpu;
541
542 for_each_online_cpu(cpu) {
Lee Schermerhorn3dd6b5f2010-05-26 14:45:04 -0700543 int node = cpu_to_mem(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 struct page *page;
545
Vlastimil Babka96db8002015-09-08 15:03:50 -0700546 page = __alloc_pages_node(node,
Johannes Weinere97ca8e2014-03-10 15:49:43 -0700547 GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
Christoph Lameterfbd98162006-09-25 23:31:45 -0700548 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 if (!page)
550 goto out_cleanup;
551 per_cpu(cpu_profile_hits, cpu)[1]
552 = (struct profile_hit *)page_address(page);
Vlastimil Babka96db8002015-09-08 15:03:50 -0700553 page = __alloc_pages_node(node,
Johannes Weinere97ca8e2014-03-10 15:49:43 -0700554 GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
Christoph Lameterfbd98162006-09-25 23:31:45 -0700555 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 if (!page)
557 goto out_cleanup;
558 per_cpu(cpu_profile_hits, cpu)[0]
559 = (struct profile_hit *)page_address(page);
560 }
561 return 0;
562out_cleanup:
563 prof_on = 0;
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700564 smp_mb();
Jens Axboe15c8b6c2008-05-09 09:39:44 +0200565 on_each_cpu(profile_nop, NULL, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 for_each_online_cpu(cpu) {
567 struct page *page;
568
569 if (per_cpu(cpu_profile_hits, cpu)[0]) {
570 page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
571 per_cpu(cpu_profile_hits, cpu)[0] = NULL;
572 __free_page(page);
573 }
574 if (per_cpu(cpu_profile_hits, cpu)[1]) {
575 page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
576 per_cpu(cpu_profile_hits, cpu)[1] = NULL;
577 __free_page(page);
578 }
579 }
580 return -1;
581}
582#else
583#define create_hash_tables() ({ 0; })
584#endif
585
Al Viro84196412008-11-22 17:36:44 +0000586int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587{
588 struct proc_dir_entry *entry;
Srivatsa S. Bhatc270a812014-03-11 02:12:08 +0530589 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
591 if (!prof_on)
592 return 0;
Srivatsa S. Bhatc270a812014-03-11 02:12:08 +0530593
594 cpu_notifier_register_begin();
595
596 if (create_hash_tables()) {
597 err = -ENOMEM;
598 goto out;
599 }
600
Denis V. Lunevc33fff02008-04-29 01:02:31 -0700601 entry = proc_create("profile", S_IWUSR | S_IRUGO,
602 NULL, &proc_profile_operations);
Paolo Ciarrocchi1ad82fd2008-01-25 21:08:33 +0100603 if (!entry)
Srivatsa S. Bhatc270a812014-03-11 02:12:08 +0530604 goto out;
David Howells271a15e2013-04-12 00:38:51 +0100605 proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t));
Srivatsa S. Bhatc270a812014-03-11 02:12:08 +0530606 __hotcpu_notifier(profile_cpu_callback, 0);
607
608out:
609 cpu_notifier_register_done();
610 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611}
Paul Gortmakerc96d6662014-04-03 14:48:35 -0700612subsys_initcall(create_proc_profile);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613#endif /* CONFIG_PROC_FS */