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authorMel Gorman <mel@csn.ul.ie>2009-09-22 04:02:47 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-22 18:17:34 +0400
commitc9d05cfc001fef3d6d37651e19ab9227a32b71f5 (patch)
treeac5f54c9fcf8336c7787fca63875b18621ee3fd1 /Documentation/trace
parent0d3d062a6e289e065bd0aa537a6806a1806bf8aa (diff)
downloadlinux-c9d05cfc001fef3d6d37651e19ab9227a32b71f5.tar.xz
tracing, page-allocator: add a postprocessing script for page-allocator-related ftrace events
This patch adds a simple post-processing script for the page-allocator-related trace events. It can be used to give an indication of who the most allocator-intensive processes are and how often the zone lock was taken during the tracing period. Example output looks like Process Pages Pages Pages Pages PCPU PCPU PCPU Fragment Fragment MigType Fragment Fragment Unknown details allocd allocd freed freed pages drains refills Fallback Causing Changed Severe Moderate under lock direct pagevec drain swapper-0 0 0 2 0 0 0 0 0 0 0 0 0 0 Xorg-3770 10603 5952 3685 6978 5996 194 192 0 0 0 0 0 0 modprobe-21397 51 0 0 86 31 1 0 0 0 0 0 0 0 xchat-5370 228 93 0 0 0 0 3 0 0 0 0 0 0 awesome-4317 32 32 0 0 0 0 32 0 0 0 0 0 0 thinkfan-3863 2 0 1 1 0 0 0 0 0 0 0 0 0 hald-addon-stor-3935 2 0 0 0 0 0 0 0 0 0 0 0 0 akregator-4506 1 1 0 0 0 0 1 0 0 0 0 0 0 xmms-14888 0 0 1 0 0 0 0 0 0 0 0 0 0 khelper-12 1 0 0 0 0 0 0 0 0 0 0 0 0 Optionally, the output can include information on the parent or aggregate based on process name instead of aggregating based on each pid. Example output including parent information and stripped out the PID looks something like; Process Pages Pages Pages Pages PCPU PCPU PCPU Fragment Fragment MigType Fragment Fragment Unknown details allocd allocd freed freed pages drains refills Fallback Causing Changed Severe Moderate under lock direct pagevec drain gdm-3756 :: Xorg-3770 3796 2976 99 3813 3224 104 98 0 0 0 0 0 0 init-1 :: hald-3892 1 0 0 0 0 0 0 0 0 0 0 0 0 git-21447 :: editor-21448 4 0 4 0 0 0 0 0 0 0 0 0 0 This says that Xorg allocated 3796 pages and it's parent process is gdm with a PID of 3756; The postprocessor parses the text output of tracing. While there is a binary format, the expectation is that the binary output can be readily translated into text and post-processed offline. Obviously if the text format changes, the parser will break but the regular expression parser is fairly rudimentary so should be readily adjustable. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Ming Chun <macli@brc.ubc.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/trace')
-rw-r--r--Documentation/trace/postprocess/trace-pagealloc-postprocess.pl418
1 files changed, 418 insertions, 0 deletions
diff --git a/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl b/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
new file mode 100644
index 000000000000..7df50e8cf4d9
--- /dev/null
+++ b/Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
@@ -0,0 +1,418 @@
+#!/usr/bin/perl
+# This is a POC (proof of concept or piece of crap, take your pick) for reading the
+# text representation of trace output related to page allocation. It makes an attempt
+# to extract some high-level information on what is going on. The accuracy of the parser
+# may vary considerably
+#
+# Example usage: trace-pagealloc-postprocess.pl < /sys/kernel/debug/tracing/trace_pipe
+# other options
+# --prepend-parent Report on the parent proc and PID
+# --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_PAGE_ALLOC => 1;
+use constant MM_PAGE_FREE_DIRECT => 2;
+use constant MM_PAGEVEC_FREE => 3;
+use constant MM_PAGE_PCPU_DRAIN => 4;
+use constant MM_PAGE_ALLOC_ZONE_LOCKED => 5;
+use constant MM_PAGE_ALLOC_EXTFRAG => 6;
+use constant EVENT_UNKNOWN => 7;
+
+# Constants used to track state
+use constant STATE_PCPU_PAGES_DRAINED => 8;
+use constant STATE_PCPU_PAGES_REFILLED => 9;
+
+# High-level events extrapolated from tracepoints
+use constant HIGH_PCPU_DRAINS => 10;
+use constant HIGH_PCPU_REFILLS => 11;
+use constant HIGH_EXT_FRAGMENT => 12;
+use constant HIGH_EXT_FRAGMENT_SEVERE => 13;
+use constant HIGH_EXT_FRAGMENT_MODERATE => 14;
+use constant HIGH_EXT_FRAGMENT_CHANGED => 15;
+
+my %perprocesspid;
+my %perprocess;
+my $opt_ignorepid;
+my $opt_read_procstat;
+my $opt_prepend_parent;
+
+# 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,
+ 'prepend-parent' => \$opt_prepend_parent,
+);
+
+# Defaults for dynamically discovered regex's
+my $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])';
+
+# Dyanically discovered regex
+my $regex_fragdetails;
+
+# 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")) {
+ $regex = $default;
+ } else {
+ my $line;
+ while (!eof(FORMAT)) {
+ $line = <FORMAT>;
+ if ($line =~ /^print fmt:\s"(.*)",.*/) {
+ $regex = $1;
+ $regex =~ s/%p/\([0-9a-f]*\)/g;
+ $regex =~ s/%d/\([-0-9]*\)/g;
+ $regex =~ s/%lu/\([0-9]*\)/g;
+ }
+ }
+ }
+
+ # 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 $expected) {
+ print("WARNING: Format not as expected '$key' != '$expected'");
+ $regex =~ s/$key=\((.*)\)/$key=$1/;
+ }
+ }
+
+ if (defined shift) {
+ die("Fewer fields than expected in format");
+ }
+
+ return $regex;
+}
+$regex_fragdetails = generate_traceevent_regex("kmem/mm_page_alloc_extfrag",
+ $regex_fragdetails_default,
+ "page", "pfn",
+ "alloc_order", "fallback_order", "pageblock_order",
+ "alloc_migratetype", "fallback_migratetype",
+ "fragmenting", "change_ownership");
+
+sub read_statline($) {
+ 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($$) {
+ my $pid = $_[0];
+ my $statline = $_[1];
+
+ if ($pid == 0) {
+ return "swapper-0";
+ }
+
+ if ($statline !~ /$regex_statname/o) {
+ die("Failed to math stat line for process name :: $statline");
+ }
+ return "$1-$pid";
+}
+
+sub parent_info($$) {
+ my $pid = $_[0];
+ my $statline = $_[1];
+ my $ppid;
+
+ if ($pid == 0) {
+ return "NOPARENT-0";
+ }
+
+ if ($statline !~ /$regex_statppid/o) {
+ die("Failed to match stat line process ppid:: $statline");
+ }
+
+ # Read the ppid stat line
+ $ppid = $1;
+ return guess_process_pid($ppid, read_statline($ppid));
+}
+
+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;
+ $tracepoint = $4;
+
+ if ($opt_read_procstat || $opt_prepend_parent) {
+ $process_pid =~ /(.*)-([0-9]*)$/;
+ my $process = $1;
+ my $pid = $2;
+
+ $statline = read_statline($pid);
+
+ if ($opt_read_procstat && $process eq '') {
+ $process_pid = guess_process_pid($pid, $statline);
+ }
+
+ if ($opt_prepend_parent) {
+ $process_pid = parent_info($pid, $statline) . " :: $process_pid";
+ }
+ }
+
+ # Unnecessary in this script. Uncomment if required
+ # $cpus = $2;
+ # $timestamp = $3;
+ } else {
+ next;
+ }
+
+ # Perl Switch() sucks majorly
+ if ($tracepoint eq "mm_page_alloc") {
+ $perprocesspid{$process_pid}->{MM_PAGE_ALLOC}++;
+ } elsif ($tracepoint eq "mm_page_free_direct") {
+ $perprocesspid{$process_pid}->{MM_PAGE_FREE_DIRECT}++;
+ } elsif ($tracepoint eq "mm_pagevec_free") {
+ $perprocesspid{$process_pid}->{MM_PAGEVEC_FREE}++;
+ } elsif ($tracepoint eq "mm_page_pcpu_drain") {
+ $perprocesspid{$process_pid}->{MM_PAGE_PCPU_DRAIN}++;
+ $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED}++;
+ } elsif ($tracepoint eq "mm_page_alloc_zone_locked") {
+ $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED}++;
+ $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED}++;
+ } elsif ($tracepoint eq "mm_page_alloc_extfrag") {
+
+ # Extract the details of the event now
+ $details = $5;
+
+ my ($page, $pfn);
+ my ($alloc_order, $fallback_order, $pageblock_order);
+ my ($alloc_migratetype, $fallback_migratetype);
+ my ($fragmenting, $change_ownership);
+
+ if ($details !~ /$regex_fragdetails/o) {
+ print "WARNING: Failed to parse mm_page_alloc_extfrag as expected\n";
+ next;
+ }
+
+ $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG}++;
+ $page = $1;
+ $pfn = $2;
+ $alloc_order = $3;
+ $fallback_order = $4;
+ $pageblock_order = $5;
+ $alloc_migratetype = $6;
+ $fallback_migratetype = $7;
+ $fragmenting = $8;
+ $change_ownership = $9;
+
+ if ($fragmenting) {
+ $perprocesspid{$process_pid}->{HIGH_EXT_FRAG}++;
+ if ($fallback_order <= 3) {
+ $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE}++;
+ } else {
+ $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE}++;
+ }
+ }
+ if ($change_ownership) {
+ $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED}++;
+ }
+ } else {
+ $perprocesspid{$process_pid}->{EVENT_UNKNOWN}++;
+ }
+
+ # Catch a full pcpu drain event
+ if ($perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED} &&
+ $tracepoint ne "mm_page_pcpu_drain") {
+
+ $perprocesspid{$process_pid}->{HIGH_PCPU_DRAINS}++;
+ $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_DRAINED} = 0;
+ }
+
+ # Catch a full pcpu refill event
+ if ($perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED} &&
+ $tracepoint ne "mm_page_alloc_zone_locked") {
+ $perprocesspid{$process_pid}->{HIGH_PCPU_REFILLS}++;
+ $perprocesspid{$process_pid}->{STATE_PCPU_PAGES_REFILLED} = 0;
+ }
+
+ 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;
+
+ printf("\n");
+ printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s\n",
+ "Process", "Pages", "Pages", "Pages", "Pages", "PCPU", "PCPU", "PCPU", "Fragment", "Fragment", "MigType", "Fragment", "Fragment", "Unknown");
+ printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s\n",
+ "details", "allocd", "allocd", "freed", "freed", "pages", "drains", "refills", "Fallback", "Causing", "Changed", "Severe", "Moderate", "");
+
+ printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s\n",
+ "", "", "under lock", "direct", "pagevec", "drain", "", "", "", "", "", "", "", "");
+
+ foreach $process_pid (keys %stats) {
+ # Dump final aggregates
+ if ($stats{$process_pid}->{STATE_PCPU_PAGES_DRAINED}) {
+ $stats{$process_pid}->{HIGH_PCPU_DRAINS}++;
+ $stats{$process_pid}->{STATE_PCPU_PAGES_DRAINED} = 0;
+ }
+ if ($stats{$process_pid}->{STATE_PCPU_PAGES_REFILLED}) {
+ $stats{$process_pid}->{HIGH_PCPU_REFILLS}++;
+ $stats{$process_pid}->{STATE_PCPU_PAGES_REFILLED} = 0;
+ }
+
+ printf("%-" . $max_strlen . "s %8d %10d %8d %8d %8d %8d %8d %8d %8d %8d %8d %8d %8d\n",
+ $process_pid,
+ $stats{$process_pid}->{MM_PAGE_ALLOC},
+ $stats{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED},
+ $stats{$process_pid}->{MM_PAGE_FREE_DIRECT},
+ $stats{$process_pid}->{MM_PAGEVEC_FREE},
+ $stats{$process_pid}->{MM_PAGE_PCPU_DRAIN},
+ $stats{$process_pid}->{HIGH_PCPU_DRAINS},
+ $stats{$process_pid}->{HIGH_PCPU_REFILLS},
+ $stats{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG},
+ $stats{$process_pid}->{HIGH_EXT_FRAG},
+ $stats{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED},
+ $stats{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE},
+ $stats{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE},
+ $stats{$process_pid}->{EVENT_UNKNOWN});
+ }
+}
+
+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_PAGE_ALLOC} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC};
+ $perprocess{$process}->{MM_PAGE_ALLOC_ZONE_LOCKED} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_ZONE_LOCKED};
+ $perprocess{$process}->{MM_PAGE_FREE_DIRECT} += $perprocesspid{$process_pid}->{MM_PAGE_FREE_DIRECT};
+ $perprocess{$process}->{MM_PAGEVEC_FREE} += $perprocesspid{$process_pid}->{MM_PAGEVEC_FREE};
+ $perprocess{$process}->{MM_PAGE_PCPU_DRAIN} += $perprocesspid{$process_pid}->{MM_PAGE_PCPU_DRAIN};
+ $perprocess{$process}->{HIGH_PCPU_DRAINS} += $perprocesspid{$process_pid}->{HIGH_PCPU_DRAINS};
+ $perprocess{$process}->{HIGH_PCPU_REFILLS} += $perprocesspid{$process_pid}->{HIGH_PCPU_REFILLS};
+ $perprocess{$process}->{MM_PAGE_ALLOC_EXTFRAG} += $perprocesspid{$process_pid}->{MM_PAGE_ALLOC_EXTFRAG};
+ $perprocess{$process}->{HIGH_EXT_FRAG} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAG};
+ $perprocess{$process}->{HIGH_EXT_FRAGMENT_CHANGED} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_CHANGED};
+ $perprocess{$process}->{HIGH_EXT_FRAGMENT_SEVERE} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_SEVERE};
+ $perprocess{$process}->{HIGH_EXT_FRAGMENT_MODERATE} += $perprocesspid{$process_pid}->{HIGH_EXT_FRAGMENT_MODERATE};
+ $perprocess{$process}->{EVENT_UNKNOWN} += $perprocesspid{$process_pid}->{EVENT_UNKNOWN};
+ }
+}
+
+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();