--- /dev/null
+#!/usr/bin/perl
+# This is a POC for reading the text representation of trace output related to
+# page reclaim. It makes an attempt to extract some high-level information on
+# what is going on. The accuracy of the parser may vary
+#
+# Example usage: trace-vmscan-postprocess.pl < /sys/kernel/debug/tracing/trace_pipe
+# other options
+#   --read-procstat    If the trace lacks process info, get it from /proc
+#   --ignore-pid       Aggregate processes of the same name together
+#
+# Copyright (c) IBM Corporation 2009
+# Author: Mel Gorman <mel@csn.ul.ie>
+use strict;
+use Getopt::Long;
+
+# Tracepoint events
+use constant MM_VMSCAN_DIRECT_RECLAIM_BEGIN    => 1;
+use constant MM_VMSCAN_DIRECT_RECLAIM_END      => 2;
+use constant MM_VMSCAN_KSWAPD_WAKE             => 3;
+use constant MM_VMSCAN_KSWAPD_SLEEP            => 4;
+use constant MM_VMSCAN_LRU_SHRINK_ACTIVE       => 5;
+use constant MM_VMSCAN_LRU_SHRINK_INACTIVE     => 6;
+use constant MM_VMSCAN_LRU_ISOLATE             => 7;
+use constant MM_VMSCAN_WRITEPAGE_FILE_SYNC     => 8;
+use constant MM_VMSCAN_WRITEPAGE_ANON_SYNC     => 9;
+use constant MM_VMSCAN_WRITEPAGE_FILE_ASYNC    => 10;
+use constant MM_VMSCAN_WRITEPAGE_ANON_ASYNC    => 11;
+use constant MM_VMSCAN_WRITEPAGE_ASYNC         => 12;
+use constant EVENT_UNKNOWN                     => 13;
+
+# Per-order events
+use constant MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER => 11;
+use constant MM_VMSCAN_WAKEUP_KSWAPD_PERORDER  => 12;
+use constant MM_VMSCAN_KSWAPD_WAKE_PERORDER    => 13;
+use constant HIGH_KSWAPD_REWAKEUP_PERORDER     => 14;
+
+# Constants used to track state
+use constant STATE_DIRECT_BEGIN                => 15;
+use constant STATE_DIRECT_ORDER                => 16;
+use constant STATE_KSWAPD_BEGIN                        => 17;
+use constant STATE_KSWAPD_ORDER                        => 18;
+
+# High-level events extrapolated from tracepoints
+use constant HIGH_DIRECT_RECLAIM_LATENCY       => 19;
+use constant HIGH_KSWAPD_LATENCY               => 20;
+use constant HIGH_KSWAPD_REWAKEUP              => 21;
+use constant HIGH_NR_SCANNED                   => 22;
+use constant HIGH_NR_TAKEN                     => 23;
+use constant HIGH_NR_RECLAIM                   => 24;
+use constant HIGH_NR_CONTIG_DIRTY              => 25;
+
+my %perprocesspid;
+my %perprocess;
+my %last_procmap;
+my $opt_ignorepid;
+my $opt_read_procstat;
+
+my $total_wakeup_kswapd;
+my ($total_direct_reclaim, $total_direct_nr_scanned);
+my ($total_direct_latency, $total_kswapd_latency);
+my ($total_direct_writepage_file_sync, $total_direct_writepage_file_async);
+my ($total_direct_writepage_anon_sync, $total_direct_writepage_anon_async);
+my ($total_kswapd_nr_scanned, $total_kswapd_wake);
+my ($total_kswapd_writepage_file_sync, $total_kswapd_writepage_file_async);
+my ($total_kswapd_writepage_anon_sync, $total_kswapd_writepage_anon_async);
+
+# Catch sigint and exit on request
+my $sigint_report = 0;
+my $sigint_exit = 0;
+my $sigint_pending = 0;
+my $sigint_received = 0;
+sub sigint_handler {
+       my $current_time = time;
+       if ($current_time - 2 > $sigint_received) {
+               print "SIGINT received, report pending. Hit ctrl-c again to exit\n";
+               $sigint_report = 1;
+       } else {
+               if (!$sigint_exit) {
+                       print "Second SIGINT received quickly, exiting\n";
+               }
+               $sigint_exit++;
+       }
+
+       if ($sigint_exit > 3) {
+               print "Many SIGINTs received, exiting now without report\n";
+               exit;
+       }
+
+       $sigint_received = $current_time;
+       $sigint_pending = 1;
+}
+$SIG{INT} = "sigint_handler";
+
+# Parse command line options
+GetOptions(
+       'ignore-pid'     =>     \$opt_ignorepid,
+       'read-procstat'  =>     \$opt_read_procstat,
+);
+
+# Defaults for dynamically discovered regex's
+my $regex_direct_begin_default = 'order=([0-9]*) may_writepage=([0-9]*) gfp_flags=([A-Z_|]*)';
+my $regex_direct_end_default = 'nr_reclaimed=([0-9]*)';
+my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)';
+my $regex_kswapd_sleep_default = 'nid=([0-9]*)';
+my $regex_wakeup_kswapd_default = 'nid=([0-9]*) zid=([0-9]*) order=([0-9]*)';
+my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_taken=([0-9]*) contig_taken=([0-9]*) contig_dirty=([0-9]*) contig_failed=([0-9]*)';
+my $regex_lru_shrink_inactive_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) priority=([0-9]*)';
+my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_rotated=([0-9]*) priority=([0-9]*)';
+my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)';
+
+# Dyanically discovered regex
+my $regex_direct_begin;
+my $regex_direct_end;
+my $regex_kswapd_wake;
+my $regex_kswapd_sleep;
+my $regex_wakeup_kswapd;
+my $regex_lru_isolate;
+my $regex_lru_shrink_inactive;
+my $regex_lru_shrink_active;
+my $regex_writepage;
+
+# Static regex used. Specified like this for readability and for use with /o
+#                      (process_pid)     (cpus      )   ( time  )   (tpoint    ) (details)
+my $regex_traceevent = '\s*([a-zA-Z0-9-]*)\s*(\[[0-9]*\])\s*([0-9.]*):\s*([a-zA-Z_]*):\s*(.*)';
+my $regex_statname = '[-0-9]*\s\((.*)\).*';
+my $regex_statppid = '[-0-9]*\s\(.*\)\s[A-Za-z]\s([0-9]*).*';
+
+sub generate_traceevent_regex {
+       my $event = shift;
+       my $default = shift;
+       my $regex;
+
+       # Read the event format or use the default
+       if (!open (FORMAT, "/sys/kernel/debug/tracing/events/$event/format")) {
+               print("WARNING: Event $event format string not found\n");
+               return $default;
+       } else {
+               my $line;
+               while (!eof(FORMAT)) {
+                       $line = <FORMAT>;
+                       $line =~ s/, REC->.*//;
+                       if ($line =~ /^print fmt:\s"(.*)".*/) {
+                               $regex = $1;
+                               $regex =~ s/%s/\([0-9a-zA-Z|_]*\)/g;
+                               $regex =~ s/%p/\([0-9a-f]*\)/g;
+                               $regex =~ s/%d/\([-0-9]*\)/g;
+                               $regex =~ s/%ld/\([-0-9]*\)/g;
+                               $regex =~ s/%lu/\([0-9]*\)/g;
+                       }
+               }
+       }
+
+       # Can't handle the print_flags stuff but in the context of this
+       # script, it really doesn't matter
+       $regex =~ s/\(REC.*\) \? __print_flags.*//;
+
+       # Verify fields are in the right order
+       my $tuple;
+       foreach $tuple (split /\s/, $regex) {
+               my ($key, $value) = split(/=/, $tuple);
+               my $expected = shift;
+               if ($key ne $expected) {
+                       print("WARNING: Format not as expected for event $event '$key' != '$expected'\n");
+                       $regex =~ s/$key=\((.*)\)/$key=$1/;
+               }
+       }
+
+       if (defined shift) {
+               die("Fewer fields than expected in format");
+       }
+
+       return $regex;
+}
+
+$regex_direct_begin = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_direct_reclaim_begin",
+                       $regex_direct_begin_default,
+                       "order", "may_writepage",
+                       "gfp_flags");
+$regex_direct_end = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_direct_reclaim_end",
+                       $regex_direct_end_default,
+                       "nr_reclaimed");
+$regex_kswapd_wake = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_kswapd_wake",
+                       $regex_kswapd_wake_default,
+                       "nid", "order");
+$regex_kswapd_sleep = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_kswapd_sleep",
+                       $regex_kswapd_sleep_default,
+                       "nid");
+$regex_wakeup_kswapd = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_wakeup_kswapd",
+                       $regex_wakeup_kswapd_default,
+                       "nid", "zid", "order");
+$regex_lru_isolate = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_lru_isolate",
+                       $regex_lru_isolate_default,
+                       "isolate_mode", "order",
+                       "nr_requested", "nr_scanned", "nr_taken",
+                       "contig_taken", "contig_dirty", "contig_failed");
+$regex_lru_shrink_inactive = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_lru_shrink_inactive",
+                       $regex_lru_shrink_inactive_default,
+                       "nid", "zid",
+                       "lru",
+                       "nr_scanned", "nr_reclaimed", "priority");
+$regex_lru_shrink_active = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_lru_shrink_active",
+                       $regex_lru_shrink_active_default,
+                       "nid", "zid",
+                       "lru",
+                       "nr_scanned", "nr_rotated", "priority");
+$regex_writepage = generate_traceevent_regex(
+                       "vmscan/mm_vmscan_writepage",
+                       $regex_writepage_default,
+                       "page", "pfn", "flags");
+
+sub read_statline($) {
+       my $pid = $_[0];
+       my $statline;
+
+       if (open(STAT, "/proc/$pid/stat")) {
+               $statline = <STAT>;
+               close(STAT);
+       }
+
+       if ($statline eq '') {
+               $statline = "-1 (UNKNOWN_PROCESS_NAME) R 0";
+       }
+
+       return $statline;
+}
+
+sub guess_process_pid($$) {
+       my $pid = $_[0];
+       my $statline = $_[1];
+
+       if ($pid == 0) {
+               return "swapper-0";
+       }
+
+       if ($statline !~ /$regex_statname/o) {
+               die("Failed to math stat line for process name :: $statline");
+       }
+       return "$1-$pid";
+}
+
+# Convert sec.usec timestamp format
+sub timestamp_to_ms($) {
+       my $timestamp = $_[0];
+
+       my ($sec, $usec) = split (/\./, $timestamp);
+       return ($sec * 1000) + ($usec / 1000);
+}
+
+sub process_events {
+       my $traceevent;
+       my $process_pid;
+       my $cpus;
+       my $timestamp;
+       my $tracepoint;
+       my $details;
+       my $statline;
+
+       # Read each line of the event log
+EVENT_PROCESS:
+       while ($traceevent = <STDIN>) {
+               if ($traceevent =~ /$regex_traceevent/o) {
+                       $process_pid = $1;
+                       $timestamp = $3;
+                       $tracepoint = $4;
+
+                       $process_pid =~ /(.*)-([0-9]*)$/;
+                       my $process = $1;
+                       my $pid = $2;
+
+                       if ($process eq "") {
+                               $process = $last_procmap{$pid};
+                               $process_pid = "$process-$pid";
+                       }
+                       $last_procmap{$pid} = $process;
+
+                       if ($opt_read_procstat) {
+                               $statline = read_statline($pid);
+                               if ($opt_read_procstat && $process eq '') {
+                                       $process_pid = guess_process_pid($pid, $statline);
+                               }
+                       }
+               } else {
+                       next;
+               }
+
+               # Perl Switch() sucks majorly
+               if ($tracepoint eq "mm_vmscan_direct_reclaim_begin") {
+                       $timestamp = timestamp_to_ms($timestamp);
+                       $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}++;
+                       $perprocesspid{$process_pid}->{STATE_DIRECT_BEGIN} = $timestamp;
+
+                       $details = $5;
+                       if ($details !~ /$regex_direct_begin/o) {
+                               print "WARNING: Failed to parse mm_vmscan_direct_reclaim_begin as expected\n";
+                               print "         $details\n";
+                               print "         $regex_direct_begin\n";
+                               next;
+                       }
+                       my $order = $1;
+                       $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order]++;
+                       $perprocesspid{$process_pid}->{STATE_DIRECT_ORDER} = $order;
+               } elsif ($tracepoint eq "mm_vmscan_direct_reclaim_end") {
+                       # Count the event itself
+                       my $index = $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_END};
+                       $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_END}++;
+
+                       # Record how long direct reclaim took this time
+                       if (defined $perprocesspid{$process_pid}->{STATE_DIRECT_BEGIN}) {
+                               $timestamp = timestamp_to_ms($timestamp);
+                               my $order = $perprocesspid{$process_pid}->{STATE_DIRECT_ORDER};
+                               my $latency = ($timestamp - $perprocesspid{$process_pid}->{STATE_DIRECT_BEGIN});
+                               $perprocesspid{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index] = "$order-$latency";
+                       }
+               } elsif ($tracepoint eq "mm_vmscan_kswapd_wake") {
+                       $details = $5;
+                       if ($details !~ /$regex_kswapd_wake/o) {
+                               print "WARNING: Failed to parse mm_vmscan_kswapd_wake as expected\n";
+                               print "         $details\n";
+                               print "         $regex_kswapd_wake\n";
+                               next;
+                       }
+
+                       my $order = $2;
+                       $perprocesspid{$process_pid}->{STATE_KSWAPD_ORDER} = $order;
+                       if (!$perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN}) {
+                               $timestamp = timestamp_to_ms($timestamp);
+                               $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}++;
+                               $perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN} = $timestamp;
+                               $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order]++;
+                       } else {
+                               $perprocesspid{$process_pid}->{HIGH_KSWAPD_REWAKEUP}++;
+                               $perprocesspid{$process_pid}->{HIGH_KSWAPD_REWAKEUP_PERORDER}[$order]++;
+                       }
+               } elsif ($tracepoint eq "mm_vmscan_kswapd_sleep") {
+
+                       # Count the event itself
+                       my $index = $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_SLEEP};
+                       $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_SLEEP}++;
+
+                       # Record how long kswapd was awake
+                       $timestamp = timestamp_to_ms($timestamp);
+                       my $order = $perprocesspid{$process_pid}->{STATE_KSWAPD_ORDER};
+                       my $latency = ($timestamp - $perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN});
+                       $perprocesspid{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index] = "$order-$latency";
+                       $perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN} = 0;
+               } elsif ($tracepoint eq "mm_vmscan_wakeup_kswapd") {
+                       $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD}++;
+
+                       $details = $5;
+                       if ($details !~ /$regex_wakeup_kswapd/o) {
+                               print "WARNING: Failed to parse mm_vmscan_wakeup_kswapd as expected\n";
+                               print "         $details\n";
+                               print "         $regex_wakeup_kswapd\n";
+                               next;
+                       }
+                       my $order = $3;
+                       $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order]++;
+               } elsif ($tracepoint eq "mm_vmscan_lru_isolate") {
+                       $details = $5;
+                       if ($details !~ /$regex_lru_isolate/o) {
+                               print "WARNING: Failed to parse mm_vmscan_lru_isolate as expected\n";
+                               print "         $details\n";
+                               print "         $regex_lru_isolate/o\n";
+                               next;
+                       }
+                       my $nr_scanned = $4;
+                       my $nr_contig_dirty = $7;
+                       $perprocesspid{$process_pid}->{HIGH_NR_SCANNED} += $nr_scanned;
+                       $perprocesspid{$process_pid}->{HIGH_NR_CONTIG_DIRTY} += $nr_contig_dirty;
+               } elsif ($tracepoint eq "mm_vmscan_writepage") {
+                       $details = $5;
+                       if ($details !~ /$regex_writepage/o) {
+                               print "WARNING: Failed to parse mm_vmscan_writepage as expected\n";
+                               print "         $details\n";
+                               print "         $regex_writepage\n";
+                               next;
+                       }
+
+                       my $flags = $3;
+                       my $file = 0;
+                       my $sync_io = 0;
+                       if ($flags =~ /RECLAIM_WB_FILE/) {
+                               $file = 1;
+                       }
+                       if ($flags =~ /RECLAIM_WB_SYNC/) {
+                               $sync_io = 1;
+                       }
+                       if ($sync_io) {
+                               if ($file) {
+                                       $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC}++;
+                               } else {
+                                       $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC}++;
+                               }
+                       } else {
+                               if ($file) {
+                                       $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC}++;
+                               } else {
+                                       $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC}++;
+                               }
+                       }
+               } else {
+                       $perprocesspid{$process_pid}->{EVENT_UNKNOWN}++;
+               }
+
+               if ($sigint_pending) {
+                       last EVENT_PROCESS;
+               }
+       }
+}
+
+sub dump_stats {
+       my $hashref = shift;
+       my %stats = %$hashref;
+
+       # Dump per-process stats
+       my $process_pid;
+       my $max_strlen = 0;
+
+       # Get the maximum process name
+       foreach $process_pid (keys %perprocesspid) {
+               my $len = length($process_pid);
+               if ($len > $max_strlen) {
+                       $max_strlen = $len;
+               }
+       }
+       $max_strlen += 2;
+
+       # Work out latencies
+       printf("\n") if !$opt_ignorepid;
+       printf("Reclaim latencies expressed as order-latency_in_ms\n") if !$opt_ignorepid;
+       foreach $process_pid (keys %stats) {
+
+               if (!$stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[0] &&
+                               !$stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[0]) {
+                       next;
+               }
+
+               printf "%-" . $max_strlen . "s ", $process_pid if !$opt_ignorepid;
+               my $index = 0;
+               while (defined $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index] ||
+                       defined $stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index]) {
+
+                       if ($stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]) {
+                               printf("%s ", $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]) if !$opt_ignorepid;
+                               my ($dummy, $latency) = split(/-/, $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]);
+                               $total_direct_latency += $latency;
+                       } else {
+                               printf("%s ", $stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index]) if !$opt_ignorepid;
+                               my ($dummy, $latency) = split(/-/, $stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index]);
+                               $total_kswapd_latency += $latency;
+                       }
+                       $index++;
+               }
+               print "\n" if !$opt_ignorepid;
+       }
+
+       # Print out process activity
+       printf("\n");
+       printf("%-" . $max_strlen . "s %8s %10s   %8s   %8s %8s %8s %8s\n", "Process", "Direct",  "Wokeup", "Pages",   "Pages",   "Pages",     "Time");
+       printf("%-" . $max_strlen . "s %8s %10s   %8s   %8s %8s %8s %8s\n", "details", "Rclms",   "Kswapd", "Scanned", "Sync-IO", "ASync-IO",  "Stalled");
+       foreach $process_pid (keys %stats) {
+
+               if (!$stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}) {
+                       next;
+               }
+
+               $total_direct_reclaim += $stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN};
+               $total_wakeup_kswapd += $stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD};
+               $total_direct_nr_scanned += $stats{$process_pid}->{HIGH_NR_SCANNED};
+               $total_direct_writepage_file_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC};
+               $total_direct_writepage_anon_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC};
+               $total_direct_writepage_file_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC};
+
+               $total_direct_writepage_anon_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC};
+
+               my $index = 0;
+               my $this_reclaim_delay = 0;
+               while (defined $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]) {
+                        my ($dummy, $latency) = split(/-/, $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]);
+                       $this_reclaim_delay += $latency;
+                       $index++;
+               }
+
+               printf("%-" . $max_strlen . "s %8d %10d   %8u   %8u %8u %8.3f",
+                       $process_pid,
+                       $stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN},
+                       $stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD},
+                       $stats{$process_pid}->{HIGH_NR_SCANNED},
+                       $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC},
+                       $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC},
+                       $this_reclaim_delay / 1000);
+
+               if ($stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}) {
+                       print "      ";
+                       for (my $order = 0; $order < 20; $order++) {
+                               my $count = $stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order];
+                               if ($count != 0) {
+                                       print "direct-$order=$count ";
+                               }
+                       }
+               }
+               if ($stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD}) {
+                       print "      ";
+                       for (my $order = 0; $order < 20; $order++) {
+                               my $count = $stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order];
+                               if ($count != 0) {
+                                       print "wakeup-$order=$count ";
+                               }
+                       }
+               }
+               if ($stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY}) {
+                       print "      ";
+                       my $count = $stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY};
+                       if ($count != 0) {
+                               print "contig-dirty=$count ";
+                       }
+               }
+
+               print "\n";
+       }
+
+       # Print out kswapd activity
+       printf("\n");
+       printf("%-" . $max_strlen . "s %8s %10s   %8s   %8s %8s %8s\n", "Kswapd",   "Kswapd",  "Order",     "Pages",   "Pages",  "Pages");
+       printf("%-" . $max_strlen . "s %8s %10s   %8s   %8s %8s %8s\n", "Instance", "Wakeups", "Re-wakeup", "Scanned", "Sync-IO", "ASync-IO");
+       foreach $process_pid (keys %stats) {
+
+               if (!$stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}) {
+                       next;
+               }
+
+               $total_kswapd_wake += $stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE};
+               $total_kswapd_nr_scanned += $stats{$process_pid}->{HIGH_NR_SCANNED};
+               $total_kswapd_writepage_file_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC};
+               $total_kswapd_writepage_anon_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC};
+               $total_kswapd_writepage_file_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC};
+               $total_kswapd_writepage_anon_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC};
+
+               printf("%-" . $max_strlen . "s %8d %10d   %8u   %8i %8u",
+                       $process_pid,
+                       $stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE},
+                       $stats{$process_pid}->{HIGH_KSWAPD_REWAKEUP},
+                       $stats{$process_pid}->{HIGH_NR_SCANNED},
+                       $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC},
+                       $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC});
+
+               if ($stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}) {
+                       print "      ";
+                       for (my $order = 0; $order < 20; $order++) {
+                               my $count = $stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order];
+                               if ($count != 0) {
+                                       print "wake-$order=$count ";
+                               }
+                       }
+               }
+               if ($stats{$process_pid}->{HIGH_KSWAPD_REWAKEUP}) {
+                       print "      ";
+                       for (my $order = 0; $order < 20; $order++) {
+                               my $count = $stats{$process_pid}->{HIGH_KSWAPD_REWAKEUP_PERORDER}[$order];
+                               if ($count != 0) {
+                                       print "rewake-$order=$count ";
+                               }
+                       }
+               }
+               printf("\n");
+       }
+
+       # Print out summaries
+       $total_direct_latency /= 1000;
+       $total_kswapd_latency /= 1000;
+       print "\nSummary\n";
+       print "Direct reclaims:                         $total_direct_reclaim\n";
+       print "Direct reclaim pages scanned:            $total_direct_nr_scanned\n";
+       print "Direct reclaim write file sync I/O:      $total_direct_writepage_file_sync\n";
+       print "Direct reclaim write anon sync I/O:      $total_direct_writepage_anon_sync\n";
+       print "Direct reclaim write file async I/O:     $total_direct_writepage_file_async\n";
+       print "Direct reclaim write anon async I/O:     $total_direct_writepage_anon_async\n";
+       print "Wake kswapd requests:                    $total_wakeup_kswapd\n";
+       printf "Time stalled direct reclaim:            %-1.2f seconds\n", $total_direct_latency;
+       print "\n";
+       print "Kswapd wakeups:                          $total_kswapd_wake\n";
+       print "Kswapd pages scanned:                    $total_kswapd_nr_scanned\n";
+       print "Kswapd reclaim write file sync I/O:      $total_kswapd_writepage_file_sync\n";
+       print "Kswapd reclaim write anon sync I/O:      $total_kswapd_writepage_anon_sync\n";
+       print "Kswapd reclaim write file async I/O:     $total_kswapd_writepage_file_async\n";
+       print "Kswapd reclaim write anon async I/O:     $total_kswapd_writepage_anon_async\n";
+       printf "Time kswapd awake:                      %-1.2f seconds\n", $total_kswapd_latency;
+}
+
+sub aggregate_perprocesspid() {
+       my $process_pid;
+       my $process;
+       undef %perprocess;
+
+       foreach $process_pid (keys %perprocesspid) {
+               $process = $process_pid;
+               $process =~ s/-([0-9])*$//;
+               if ($process eq '') {
+                       $process = "NO_PROCESS_NAME";
+               }
+
+               $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN} += $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN};
+               $perprocess{$process}->{MM_VMSCAN_KSWAPD_WAKE} += $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE};
+               $perprocess{$process}->{MM_VMSCAN_WAKEUP_KSWAPD} += $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD};
+               $perprocess{$process}->{HIGH_KSWAPD_REWAKEUP} += $perprocesspid{$process_pid}->{HIGH_KSWAPD_REWAKEUP};
+               $perprocess{$process}->{HIGH_NR_SCANNED} += $perprocesspid{$process_pid}->{HIGH_NR_SCANNED};
+               $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC};
+               $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC};
+               $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC};
+               $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC};
+
+               for (my $order = 0; $order < 20; $order++) {
+                       $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order] += $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order];
+                       $perprocess{$process}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order] += $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order];
+                       $perprocess{$process}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order] += $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order];
+
+               }
+
+               # Aggregate direct reclaim latencies
+               my $wr_index = $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_END};
+               my $rd_index = 0;
+               while (defined $perprocesspid{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$rd_index]) {
+                       $perprocess{$process}->{HIGH_DIRECT_RECLAIM_LATENCY}[$wr_index] = $perprocesspid{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$rd_index];
+                       $rd_index++;
+                       $wr_index++;
+               }
+               $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_END} = $wr_index;
+
+               # Aggregate kswapd latencies
+               my $wr_index = $perprocess{$process}->{MM_VMSCAN_KSWAPD_SLEEP};
+               my $rd_index = 0;
+               while (defined $perprocesspid{$process_pid}->{HIGH_KSWAPD_LATENCY}[$rd_index]) {
+                       $perprocess{$process}->{HIGH_KSWAPD_LATENCY}[$wr_index] = $perprocesspid{$process_pid}->{HIGH_KSWAPD_LATENCY}[$rd_index];
+                       $rd_index++;
+                       $wr_index++;
+               }
+               $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_END} = $wr_index;
+       }
+}
+
+sub report() {
+       if (!$opt_ignorepid) {
+               dump_stats(\%perprocesspid);
+       } else {
+               aggregate_perprocesspid();
+               dump_stats(\%perprocess);
+       }
+}
+
+# Process events or signals until neither is available
+sub signal_loop() {
+       my $sigint_processed;
+       do {
+               $sigint_processed = 0;
+               process_events();
+
+               # Handle pending signals if any
+               if ($sigint_pending) {
+                       my $current_time = time;
+
+                       if ($sigint_exit) {
+                               print "Received exit signal\n";
+                               $sigint_pending = 0;
+                       }
+                       if ($sigint_report) {
+                               if ($current_time >= $sigint_received + 2) {
+                                       report();
+                                       $sigint_report = 0;
+                                       $sigint_pending = 0;
+                                       $sigint_processed = 1;
+                               }
+                       }
+               }
+       } while ($sigint_pending || $sigint_processed);
+}
+
+signal_loop();
+report();