kernel/trace/kmemtrace.c

   1 /*
   2  * Memory allocator tracing
   3  *
   4  * Copyright (C) 2008 Eduard - Gabriel Munteanu
   5  * Copyright (C) 2008 Pekka Enberg <penberg@cs.helsinki.fi>
   6  * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
   7  */
   8
   9 #include <linux/dcache.h>
  10 #include <linux/debugfs.h>
  11 #include <linux/fs.h>
  12 #include <linux/seq_file.h>
  13 #include <trace/kmemtrace.h>
  14
  15 #include "trace.h"
  16 #include "trace_output.h"
  17
  18 /* Select an alternative, minimalistic output than the original one */
  19 #define TRACE_KMEM_OPT_MINIMAL  0x1
  20
  21 static struct tracer_opt kmem_opts[] = {
  22         /* Default disable the minimalistic output */
  23         { TRACER_OPT(kmem_minimalistic, TRACE_KMEM_OPT_MINIMAL) },
  24         { }
  25 };
  26
  27 static struct tracer_flags kmem_tracer_flags = {
  28         .val = 0,
  29         .opts = kmem_opts
  30 };
  31
  32
  33 static bool kmem_tracing_enabled __read_mostly;
  34 static struct trace_array *kmemtrace_array;
  35
  36 static int kmem_trace_init(struct trace_array *tr)
  37 {
  38         int cpu;
  39         kmemtrace_array = tr;
  40
  41         for_each_cpu_mask(cpu, cpu_possible_map)
  42                 tracing_reset(tr, cpu);
  43
  44         kmem_tracing_enabled = true;
  45
  46         return 0;
  47 }
  48
  49 static void kmem_trace_reset(struct trace_array *tr)
  50 {
  51         kmem_tracing_enabled = false;
  52 }
  53
  54 static void kmemtrace_headers(struct seq_file *s)
  55 {
  56         /* Don't need headers for the original kmemtrace output */
  57         if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
  58                 return;
  59
  60         seq_printf(s, "#\n");
  61         seq_printf(s, "# ALLOC  TYPE  REQ   GIVEN  FLAGS     "
  62                         "      POINTER         NODE    CALLER\n");
  63         seq_printf(s, "# FREE   |      |     |       |       "
  64                         "       |   |            |        |\n");
  65         seq_printf(s, "# |\n\n");
  66 }
  67
  68 /*
  69  * The two following functions give the original output from kmemtrace,
  70  * or something close to....perhaps they need some missing things
  71  */
  72 static enum print_line_t
  73 kmemtrace_print_alloc_original(struct trace_iterator *iter,
  74                                 struct kmemtrace_alloc_entry *entry)
  75 {
  76         struct trace_seq *s = &iter->seq;
  77         int ret;
  78
  79         /* Taken from the old linux/kmemtrace.h */
  80         ret = trace_seq_printf(s, "type_id %d call_site %lu ptr %lu "
  81           "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
  82            entry->type_id, entry->call_site, (unsigned long) entry->ptr,
  83            (unsigned long) entry->bytes_req, (unsigned long) entry->bytes_alloc,
  84            (unsigned long) entry->gfp_flags, entry->node);
  85
  86         if (!ret)
  87                 return TRACE_TYPE_PARTIAL_LINE;
  88
  89         return TRACE_TYPE_HANDLED;
  90 }
  91
  92 static enum print_line_t
  93 kmemtrace_print_free_original(struct trace_iterator *iter,
  94                                 struct kmemtrace_free_entry *entry)
  95 {
  96         struct trace_seq *s = &iter->seq;
  97         int ret;
  98
  99         /* Taken from the old linux/kmemtrace.h */
 100         ret = trace_seq_printf(s, "type_id %d call_site %lu ptr %lu\n",
 101            entry->type_id, entry->call_site, (unsigned long) entry->ptr);
 102
 103         if (!ret)
 104                 return TRACE_TYPE_PARTIAL_LINE;
 105
 106         return TRACE_TYPE_HANDLED;
 107 }
 108
 109
 110 /* The two other following provide a more minimalistic output */
 111 static enum print_line_t
 112 kmemtrace_print_alloc_compress(struct trace_iterator *iter,
 113                                         struct kmemtrace_alloc_entry *entry)
 114 {
 115         struct trace_seq *s = &iter->seq;
 116         int ret;
 117
 118         /* Alloc entry */
 119         ret = trace_seq_printf(s, "  +      ");
 120         if (!ret)
 121                 return TRACE_TYPE_PARTIAL_LINE;
 122
 123         /* Type */
 124         switch (entry->type_id) {
 125         case KMEMTRACE_TYPE_KMALLOC:
 126                 ret = trace_seq_printf(s, "K   ");
 127                 break;
 128         case KMEMTRACE_TYPE_CACHE:
 129                 ret = trace_seq_printf(s, "C   ");
 130                 break;
 131         case KMEMTRACE_TYPE_PAGES:
 132                 ret = trace_seq_printf(s, "P   ");
 133                 break;
 134         default:
 135                 ret = trace_seq_printf(s, "?   ");
 136         }
 137
 138         if (!ret)
 139                 return TRACE_TYPE_PARTIAL_LINE;
 140
 141         /* Requested */
 142         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_req);
 143         if (!ret)
 144                 return TRACE_TYPE_PARTIAL_LINE;
 145
 146         /* Allocated */
 147         ret = trace_seq_printf(s, "%4zu   ", entry->bytes_alloc);
 148         if (!ret)
 149                 return TRACE_TYPE_PARTIAL_LINE;
 150
 151         /* Flags
 152          * TODO: would be better to see the name of the GFP flag names
 153          */
 154         ret = trace_seq_printf(s, "%08x   ", entry->gfp_flags);
 155         if (!ret)
 156                 return TRACE_TYPE_PARTIAL_LINE;
 157
 158         /* Pointer to allocated */
 159         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 160         if (!ret)
 161                 return TRACE_TYPE_PARTIAL_LINE;
 162
 163         /* Node */
 164         ret = trace_seq_printf(s, "%4d   ", entry->node);
 165         if (!ret)
 166                 return TRACE_TYPE_PARTIAL_LINE;
 167
 168         /* Call site */
 169         ret = seq_print_ip_sym(s, entry->call_site, 0);
 170         if (!ret)
 171                 return TRACE_TYPE_PARTIAL_LINE;
 172
 173         if (!trace_seq_printf(s, "\n"))
 174                 return TRACE_TYPE_PARTIAL_LINE;
 175
 176         return TRACE_TYPE_HANDLED;
 177 }
 178
 179 static enum print_line_t
 180 kmemtrace_print_free_compress(struct trace_iterator *iter,
 181                                 struct kmemtrace_free_entry *entry)
 182 {
 183         struct trace_seq *s = &iter->seq;
 184         int ret;
 185
 186         /* Free entry */
 187         ret = trace_seq_printf(s, "  -      ");
 188         if (!ret)
 189                 return TRACE_TYPE_PARTIAL_LINE;
 190
 191         /* Type */
 192         switch (entry->type_id) {
 193         case KMEMTRACE_TYPE_KMALLOC:
 194                 ret = trace_seq_printf(s, "K     ");
 195                 break;
 196         case KMEMTRACE_TYPE_CACHE:
 197                 ret = trace_seq_printf(s, "C     ");
 198                 break;
 199         case KMEMTRACE_TYPE_PAGES:
 200                 ret = trace_seq_printf(s, "P     ");
 201                 break;
 202         default:
 203                 ret = trace_seq_printf(s, "?     ");
 204         }
 205
 206         if (!ret)
 207                 return TRACE_TYPE_PARTIAL_LINE;
 208
 209         /* Skip requested/allocated/flags */
 210         ret = trace_seq_printf(s, "                       ");
 211         if (!ret)
 212                 return TRACE_TYPE_PARTIAL_LINE;
 213
 214         /* Pointer to allocated */
 215         ret = trace_seq_printf(s, "0x%tx   ", (ptrdiff_t)entry->ptr);
 216         if (!ret)
 217                 return TRACE_TYPE_PARTIAL_LINE;
 218
 219         /* Skip node */
 220         ret = trace_seq_printf(s, "       ");
 221         if (!ret)
 222                 return TRACE_TYPE_PARTIAL_LINE;
 223
 224         /* Call site */
 225         ret = seq_print_ip_sym(s, entry->call_site, 0);
 226         if (!ret)
 227                 return TRACE_TYPE_PARTIAL_LINE;
 228
 229         if (!trace_seq_printf(s, "\n"))
 230                 return TRACE_TYPE_PARTIAL_LINE;
 231
 232         return TRACE_TYPE_HANDLED;
 233 }
 234
 235 static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
 236 {
 237         struct trace_entry *entry = iter->ent;
 238
 239         switch (entry->type) {
 240         case TRACE_KMEM_ALLOC: {
 241                 struct kmemtrace_alloc_entry *field;
 242                 trace_assign_type(field, entry);
 243                 if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
 244                         return kmemtrace_print_alloc_compress(iter, field);
 245                 else
 246                         return kmemtrace_print_alloc_original(iter, field);
 247         }
 248
 249         case TRACE_KMEM_FREE: {
 250                 struct kmemtrace_free_entry *field;
 251                 trace_assign_type(field, entry);
 252                 if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
 253                         return kmemtrace_print_free_compress(iter, field);
 254                 else
 255                         return kmemtrace_print_free_original(iter, field);
 256         }
 257
 258         default:
 259                 return TRACE_TYPE_UNHANDLED;
 260         }
 261 }
 262
 263 /* Trace allocations */
 264 void kmemtrace_mark_alloc_node(enum kmemtrace_type_id type_id,
 265                              unsigned long call_site,
 266                              const void *ptr,
 267                              size_t bytes_req,
 268                              size_t bytes_alloc,
 269                              gfp_t gfp_flags,
 270                              int node)
 271 {
 272         struct ring_buffer_event *event;
 273         struct kmemtrace_alloc_entry *entry;
 274         struct trace_array *tr = kmemtrace_array;
 275
 276         if (!kmem_tracing_enabled)
 277                 return;
 278
 279         event = trace_buffer_lock_reserve(tr, TRACE_KMEM_ALLOC,
 280                                           sizeof(*entry), 0, 0);
 281         if (!event)
 282                 return;
 283         entry   = ring_buffer_event_data(event);
 284
 285         entry->call_site = call_site;
 286         entry->ptr = ptr;
 287         entry->bytes_req = bytes_req;
 288         entry->bytes_alloc = bytes_alloc;
 289         entry->gfp_flags = gfp_flags;
 290         entry->node     =       node;
 291
 292         trace_buffer_unlock_commit(tr, event, 0, 0);
 293 }
 294 EXPORT_SYMBOL(kmemtrace_mark_alloc_node);
 295
 296 void kmemtrace_mark_free(enum kmemtrace_type_id type_id,
 297                        unsigned long call_site,
 298                        const void *ptr)
 299 {
 300         struct ring_buffer_event *event;
 301         struct kmemtrace_free_entry *entry;
 302         struct trace_array *tr = kmemtrace_array;
 303
 304         if (!kmem_tracing_enabled)
 305                 return;
 306
 307         event = trace_buffer_lock_reserve(tr, TRACE_KMEM_FREE,
 308                                           sizeof(*entry), 0, 0);
 309         if (!event)
 310                 return;
 311         entry   = ring_buffer_event_data(event);
 312         entry->type_id  = type_id;
 313         entry->call_site = call_site;
 314         entry->ptr = ptr;
 315
 316         trace_buffer_unlock_commit(tr, event, 0, 0);
 317 }
 318 EXPORT_SYMBOL(kmemtrace_mark_free);
 319
 320 static struct tracer kmem_tracer __read_mostly = {
 321         .name           = "kmemtrace",
 322         .init           = kmem_trace_init,
 323         .reset          = kmem_trace_reset,
 324         .print_line     = kmemtrace_print_line,
 325         .print_header = kmemtrace_headers,
 326         .flags          = &kmem_tracer_flags
 327 };
 328
 329 void kmemtrace_init(void)
 330 {
 331         /* earliest opportunity to start kmem tracing */
 332 }
 333
 334 static int __init init_kmem_tracer(void)
 335 {
 336         return register_tracer(&kmem_tracer);
 337 }
 338
 339 device_initcall(init_kmem_tracer);