linux/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
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   1#!/usr/bin/perl
   2# This is a POC (proof of concept or piece of crap, take your pick) for reading the
   3# text representation of trace output related to page allocation. It makes an attempt
   4# to extract some high-level information on what is going on. The accuracy of the parser
   5# may vary considerably
   6#
   7# Example usage: trace-pagealloc-postprocess.pl < /sys/kernel/debug/tracing/trace_pipe
   8# other options
   9#   --prepend-parent    Report on the parent proc and PID
  10#   --read-procstat     If the trace lacks process info, get it from /proc
  11#   --ignore-pid        Aggregate processes of the same name together
  12#
  13# Copyright (c) IBM Corporation 2009
  14# Author: Mel Gorman <mel@csn.ul.ie>
  15use strict;
  16use Getopt::Long;
  17
  18# Tracepoint events
  19use constant MM_PAGE_ALLOC              => 1;
  20use constant MM_PAGE_FREE_DIRECT        => 2;
  21use constant MM_PAGEVEC_FREE            => 3;
  22use constant MM_PAGE_PCPU_DRAIN         => 4;
  23use constant MM_PAGE_ALLOC_ZONE_LOCKED  => 5;
  24use constant MM_PAGE_ALLOC_EXTFRAG      => 6;
  25use constant EVENT_UNKNOWN              => 7;
  26
  27# Constants used to track state
  28use constant STATE_PCPU_PAGES_DRAINED   => 8;
  29use constant STATE_PCPU_PAGES_REFILLED  => 9;
  30
  31# High-level events extrapolated from tracepoints
  32use constant HIGH_PCPU_DRAINS           => 10;
  33use constant HIGH_PCPU_REFILLS          => 11;
  34use constant HIGH_EXT_FRAGMENT          => 12;
  35use constant HIGH_EXT_FRAGMENT_SEVERE   => 13;
  36use constant HIGH_EXT_FRAGMENT_MODERATE => 14;
  37use constant HIGH_EXT_FRAGMENT_CHANGED  => 15;
  38
  39my %perprocesspid;
  40my %perprocess;
  41my $opt_ignorepid;
  42my $opt_read_procstat;
  43my $opt_prepend_parent;
  44
  45# Catch sigint and exit on request
  46my $sigint_report = 0;
  47my $sigint_exit = 0;
  48my $sigint_pending = 0;
  49my $sigint_received = 0;
  50sub sigint_handler {
  51        my $current_time = time;
  52        if ($current_time - 2 > $sigint_received) {
  53                print "SIGINT received, report pending. Hit ctrl-c again to exit\n";
  54                $sigint_report = 1;
  55        } else {
  56                if (!$sigint_exit) {
  57                        print "Second SIGINT received quickly, exiting\n";
  58                }
  59                $sigint_exit++;
  60        }
  61
  62        if ($sigint_exit > 3) {
  63                print "Many SIGINTs received, exiting now without report\n";
  64                exit;
  65        }
  66
  67        $sigint_received = $current_time;
  68        $sigint_pending = 1;
  69}
  70$SIG{INT} = "sigint_handler";
  71
  72# Parse command line options
  73GetOptions(
  74        'ignore-pid'     =>     \$opt_ignorepid,
  75        'read-procstat'  =>     \$opt_read_procstat,
  76        'prepend-parent' =>     \$opt_prepend_parent,
  77);
  78
  79# Defaults for dynamically discovered regex's
  80my $regex_fragdetails_default = 'page=([0-9a-f]*) pfn=([0-9]*) alloc_order=([-0-9]*) fallback_order=([-0-9]*) pageblock_order=([-0-9]*) alloc_migratetype=([-0-9]*) fallback_migratetype=([-0-9]*) fragmenting=([-0-9]) change_ownership=([-0-9])';
  81
  82# Dyanically discovered regex
  83my $regex_fragdetails;
  84
  85# Static regex used. Specified like this for readability and for use with /o
  86#                      (process_pid)     (cpus      )   ( time  )   (tpoint    ) (details)
  87my $regex_traceevent = '\s*([a-zA-Z0-9-]*)\s*(\[[0-9]*\])\s*([0-9.]*):\s*([a-zA-Z_]*):\s*(.*)';
  88my $regex_statname = '[-0-9]*\s\((.*)\).*';
  89my $regex_statppid = '[-0-9]*\s\(.*\)\s[A-Za-z]\s([0-9]*).*';
  90
  91sub generate_traceevent_regex {
  92        my $event = shift;
  93        my $default = shift;
  94        my $regex;
  95
  96        # Read the event format or use the default
  97        if (!open (FORMAT, "/sys/kernel/debug/tracing/events/$event/format")) {
  98                $regex = $default;
  99        } else {
 100                my $line;
 101                while (!eof(FORMAT)) {
 102                        $line = <FORMAT>;
 103                        if ($line =~ /^print fmt:\s"(.*)",.*/) {
 104                                $regex = $1;
 105                                $regex =~ s/%p/\([0-9a-f]*\)/g;
 106                                $regex =~ s/%d/\([-0-9]*\)/g;
 107                                $regex =~ s/%lu/\([0-9]*\)/g;
 108                        }
 109                }
 110        }
 111
 112        # Verify fields are in the right order
 113        my $tuple;
 114        foreach $tuple (split /\s/, $regex) {
 115                my ($key, $value) = split(/=/, $tuple);
 116                my $expected = shift;
 117                if ($key ne $expected) {
 118                        print("WARNING: Format not as expected '$key' != '$expected'");
 119                        $regex =~ s/$key=\((.*)\)/$key=$1/;
 120                }
 121        }
 122
 123        if (defined shift) {
 124                die("Fewer fields than expected in format");
 125        }
 126
 127        return $regex;
 128}
 129$regex_fragdetails = generate_traceevent_regex("kmem/mm_page_alloc_extfrag",
 130                        $regex_fragdetails_default,
 131                        "page", "pfn",
 132                        "alloc_order", "fallback_order", "pageblock_order",
 133                        "alloc_migratetype", "fallback_migratetype",
 134                        "fragmenting", "change_ownership");
 135
 136sub read_statline($) {
 137        my $pid = $_[0];
 138        my $statline;
 139
 140        if (open(STAT, "/proc/$pid/stat")) {
 141                $statline = <STAT>;
 142                close(STAT);
 143        }
 144
 145        if ($statline eq '') {
 146                $statline = "-1 (UNKNOWN_PROCESS_NAME) R 0";
 147        }
 148
 149        return $statline;
 150}
 151
 152sub guess_process_pid($$) {
 153        my $pid = $_[0];
 154        my $statline = $_[1];
 155
 156        if ($pid == 0) {
 157                return "swapper-0";
 158        }
 159
 160        if ($statline !~ /$regex_statname/o) {
 161                die("Failed to math stat line for process name :: $statline");
 162        }
 163        return "$1-$pid";
 164}
 165
 166sub parent_info($$) {
 167        my $pid = $_[0];
 168        my $statline = $_[1];
 169        my $ppid;
 170
 171        if ($pid == 0) {
 172                return "NOPARENT-0";
 173        }
 174
 175        if ($statline !~ /$regex_statppid/o) {
 176                die("Failed to match stat line process ppid:: $statline");
 177        }
 178
 179        # Read the ppid stat line
 180        $ppid = $1;
 181        return guess_process_pid($ppid, read_statline($ppid));
 182}
 183
 184sub process_events {
 185        my $traceevent;
 186        my $process_pid;
 187        my $cpus;
 188        my $timestamp;
 189        my $tracepoint;
 190        my $details;
 191        my $statline;
 192
 193        # Read each line of the event log
 194EVENT_PROCESS:
 195        while ($traceevent = <STDIN>) {
 196                if ($traceevent =~ /$regex_traceevent/o) {
 197                        $process_pid = $1;
 198                        $tracepoint = $4;
 199
 200                        if ($opt_read_procstat || $opt_prepend_parent) {
 201                                $process_pid =~ /(.*)-([0-9]*)$/;
 202                                my $process = $1;
 203                                my $pid = $2;
 204
 205                                $statline = read_statline($pid);
 206
 207                                if ($opt_read_procstat && $process eq '') {
 208                                        $process_pid = guess_process_pid($pid, $statline);
 209                                }
 210
 211                                if ($opt_prepend_parent) {
 212                                        $process_pid = parent_info($pid, $statline) . " :: $process_pid";
 213                                }
 214                        }
 215
 216                        # Unnecessary in this script. Uncomment if required
 217                        # $cpus = $2;
 218                        # $timestamp = $3;
 219                } else {
 220                        next;
 221                }
 222
 223                # Perl Switch() sucks majorly
 224                if ($tracepoint eq "mm_page_alloc") {
 225                        $perprocesspid{$process_pid}->{MM_PAGE_ALLOC}++;
 226                } elsif ($tracepoint eq "mm_page_free_direct") {
 227                        $perprocesspid{$process_pid}->{MM_PAGE_FREE_DIRECT}++;
 228                } elsif ($tracepoint eq "mm_pagevec_free") {
 229                        $perprocesspid{$process_pid}->{MM_PAGEVEC_FREE}++;
 230                } elsif ($tracepoint eq "mm_page_pcpu_drain") {
 231                        $perprocesspid{$process_pid}->{MM_PAGE_PCPU_DRAIN}++;
 232                        $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED}++;
 233                } elsif ($tracepoint eq "mm_page_alloc_zone_locked") {
 234                        $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED}++;
 235                        $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED}++;
 236                } elsif ($tracepoint eq "mm_page_alloc_extfrag") {
 237
 238                        # Extract the details of the event now
 239                        $details = $5;
 240
 241                        my ($page, $pfn);
 242                        my ($alloc_order, $fallback_order, $pageblock_order);
 243                        my ($alloc_migratetype, $fallback_migratetype);
 244                        my ($fragmenting, $change_ownership);
 245
 246                        if ($details !~ /$regex_fragdetails/o) {
 247                                print "WARNING: Failed to parse mm_page_alloc_extfrag as expected\n";
 248                                next;
 249                        }
 250
 251                        $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG}++;
 252                        $page = $1;
 253                        $pfn = $2;
 254                        $alloc_order = $3;
 255                        $fallback_order = $4;
 256                        $pageblock_order = $5;
 257                        $alloc_migratetype = $6;
 258                        $fallback_migratetype = $7;
 259                        $fragmenting = $8;
 260                        $change_ownership = $9;
 261
 262                        if ($fragmenting) {
 263                                $perprocesspid{$process_pid}->{HIGH_EXT_FRAG}++;
 264                                if ($fallback_order <= 3) {
 265                                        $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE}++;
 266                                } else {
 267                                        $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE}++;
 268                                }
 269                        }
 270                        if ($change_ownership) {
 271                                $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED}++;
 272                        }
 273                } else {
 274                        $perprocesspid{$process_pid}->{EVENT_UNKNOWN}++;
 275                }
 276
 277                # Catch a full pcpu drain event
 278                if ($perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED} &&
 279                                $tracepoint ne "mm_page_pcpu_drain") {
 280
 281                        $perprocesspid{$process_pid}->{HIGH_PCPU_DRAINS}++;
 282                        $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED} = 0;
 283                }
 284
 285                # Catch a full pcpu refill event
 286                if ($perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED} &&
 287                                $tracepoint ne "mm_page_alloc_zone_locked") {
 288                        $perprocesspid{$process_pid}->{HIGH_PCPU_REFILLS}++;
 289                        $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED} = 0;
 290                }
 291
 292                if ($sigint_pending) {
 293                        last EVENT_PROCESS;
 294                }
 295        }
 296}
 297
 298sub dump_stats {
 299        my $hashref = shift;
 300        my %stats = %$hashref;
 301
 302        # Dump per-process stats
 303        my $process_pid;
 304        my $max_strlen = 0;
 305
 306        # Get the maximum process name
 307        foreach $process_pid (keys %perprocesspid) {
 308                my $len = length($process_pid);
 309                if ($len > $max_strlen) {
 310                        $max_strlen = $len;
 311                }
 312        }
 313        $max_strlen += 2;
 314
 315        printf("\n");
 316        printf("%-" . $max_strlen . "s %8s %10s   %8s %8s   %8s %8s %8s   %8s %8s %8s %8s %8s %8s\n",
 317                "Process", "Pages",  "Pages",      "Pages", "Pages", "PCPU",  "PCPU",   "PCPU",    "Fragment",  "Fragment", "MigType", "Fragment", "Fragment", "Unknown");
 318        printf("%-" . $max_strlen . "s %8s %10s   %8s %8s   %8s %8s %8s   %8s %8s %8s %8s %8s %8s\n",
 319                "details", "allocd", "allocd",     "freed", "freed", "pages", "drains", "refills", "Fallback", "Causing",   "Changed", "Severe", "Moderate", "");
 320
 321        printf("%-" . $max_strlen . "s %8s %10s   %8s %8s   %8s %8s %8s   %8s %8s %8s %8s %8s %8s\n",
 322                "",        "",       "under lock", "direct", "pagevec", "drain", "", "", "", "", "", "", "", "");
 323
 324        foreach $process_pid (keys %stats) {
 325                # Dump final aggregates
 326                if ($stats{$process_pid}->{STATE_PCPU_PAGES_DRAINED}) {
 327                        $stats{$process_pid}->{HIGH_PCPU_DRAINS}++;
 328                        $stats{$process_pid}->{STATE_PCPU_PAGES_DRAINED} = 0;
 329                }
 330                if ($stats{$process_pid}->{STATE_PCPU_PAGES_REFILLED}) {
 331                        $stats{$process_pid}->{HIGH_PCPU_REFILLS}++;
 332                        $stats{$process_pid}->{STATE_PCPU_PAGES_REFILLED} = 0;
 333                }
 334
 335                printf("%-" . $max_strlen . "s %8d %10d   %8d %8d   %8d %8d %8d   %8d %8d %8d %8d %8d %8d\n",
 336                        $process_pid,
 337                        $stats{$process_pid}->{MM_PAGE_ALLOC},
 338                        $stats{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED},
 339                        $stats{$process_pid}->{MM_PAGE_FREE_DIRECT},
 340                        $stats{$process_pid}->{MM_PAGEVEC_FREE},
 341                        $stats{$process_pid}->{MM_PAGE_PCPU_DRAIN},
 342                        $stats{$process_pid}->{HIGH_PCPU_DRAINS},
 343                        $stats{$process_pid}->{HIGH_PCPU_REFILLS},
 344                        $stats{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG},
 345                        $stats{$process_pid}->{HIGH_EXT_FRAG},
 346                        $stats{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED},
 347                        $stats{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE},
 348                        $stats{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE},
 349                        $stats{$process_pid}->{EVENT_UNKNOWN});
 350        }
 351}
 352
 353sub aggregate_perprocesspid() {
 354        my $process_pid;
 355        my $process;
 356        undef %perprocess;
 357
 358        foreach $process_pid (keys %perprocesspid) {
 359                $process = $process_pid;
 360                $process =~ s/-([0-9])*$//;
 361                if ($process eq '') {
 362                        $process = "NO_PROCESS_NAME";
 363                }
 364
 365                $perprocess{$process}->{MM_PAGE_ALLOC} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC};
 366                $perprocess{$process}->{MM_PAGE_ALLOC_ZONE_LOCKED} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED};
 367                $perprocess{$process}->{MM_PAGE_FREE_DIRECT} += $perprocesspid{$process_pid}->{MM_PAGE_FREE_DIRECT};
 368                $perprocess{$process}->{MM_PAGEVEC_FREE} += $perprocesspid{$process_pid}->{MM_PAGEVEC_FREE};
 369                $perprocess{$process}->{MM_PAGE_PCPU_DRAIN} += $perprocesspid{$process_pid}->{MM_PAGE_PCPU_DRAIN};
 370                $perprocess{$process}->{HIGH_PCPU_DRAINS} += $perprocesspid{$process_pid}->{HIGH_PCPU_DRAINS};
 371                $perprocess{$process}->{HIGH_PCPU_REFILLS} += $perprocesspid{$process_pid}->{HIGH_PCPU_REFILLS};
 372                $perprocess{$process}->{MM_PAGE_ALLOC_EXTFRAG} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG};
 373                $perprocess{$process}->{HIGH_EXT_FRAG} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAG};
 374                $perprocess{$process}->{HIGH_EXT_FRAGMENT_CHANGED} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED};
 375                $perprocess{$process}->{HIGH_EXT_FRAGMENT_SEVERE} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE};
 376                $perprocess{$process}->{HIGH_EXT_FRAGMENT_MODERATE} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE};
 377                $perprocess{$process}->{EVENT_UNKNOWN} += $perprocesspid{$process_pid}->{EVENT_UNKNOWN};
 378        }
 379}
 380
 381sub report() {
 382        if (!$opt_ignorepid) {
 383                dump_stats(\%perprocesspid);
 384        } else {
 385                aggregate_perprocesspid();
 386                dump_stats(\%perprocess);
 387        }
 388}
 389
 390# Process events or signals until neither is available
 391sub signal_loop() {
 392        my $sigint_processed;
 393        do {
 394                $sigint_processed = 0;
 395                process_events();
 396
 397                # Handle pending signals if any
 398                if ($sigint_pending) {
 399                        my $current_time = time;
 400
 401                        if ($sigint_exit) {
 402                                print "Received exit signal\n";
 403                                $sigint_pending = 0;
 404                        }
 405                        if ($sigint_report) {
 406                                if ($current_time >= $sigint_received + 2) {
 407                                        report();
 408                                        $sigint_report = 0;
 409                                        $sigint_pending = 0;
 410                                        $sigint_processed = 1;
 411                                }
 412                        }
 413                }
 414        } while ($sigint_pending || $sigint_processed);
 415}
 416
 417signal_loop();
 418report();
 419
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