FM / memory

/usr/share/systemtap/examples/memory

Name	Size	Mode	Actions
cachestat.meta	545	0644	edit dl rm
cachestat.stp	1318	0755	edit dl rm
glibc-malloc.meta	381	0644	edit dl rm
glibc-malloc.stp	2486	0755	edit dl rm
hugepage_clear_delays.meta	946	0644	edit dl rm
hugepage_clear_delays.stp	483	0755	edit dl rm
hugepage_collapse.meta	718	0644	edit dl rm
hugepage_collapse.stp	159	0755	edit dl rm
hugepage_cow_delays.meta	1106	0644	edit dl rm
hugepage_cow_delays.stp	475	0755	edit dl rm
hugepage_split.meta	756	0644	edit dl rm
hugepage_split.stp	153	0755	edit dl rm
hw_watch_addr.meta	787	0644	edit dl rm
hw_watch_addr.stp	167	0755	edit dl rm
hw_watch_addr.tcl	97	0644	edit dl rm
hw_watch_sym.meta	715	0644	edit dl rm
hw_watch_sym.stp	167	0755	edit dl rm
hw_watch_sym.tcl	97	0644	edit dl rm
kmalloc-top	3888	0755	edit dl rm
kmalloc-top.meta	695	0644	edit dl rm
last_100_frees.meta	420	0644	edit dl rm
last_100_frees.stp	803	0755	edit dl rm
last_100_frees.tcl	79	0644	edit dl rm
last_100_frees.txt	774	0644	edit dl rm
mmanonpage.meta	1225	0644	edit dl rm
mmanonpage.stp	1816	0755	edit dl rm
mmfilepage.meta	1033	0644	edit dl rm
mmfilepage.stp	3537	0755	edit dl rm
mmreclaim.meta	606	0644	edit dl rm
mmreclaim.stp	5232	0755	edit dl rm
mmwriteback.meta	1114	0644	edit dl rm
mmwriteback.stp	1900	0755	edit dl rm
numa_faults.meta	702	0644	edit dl rm
numa_faults.stp	973	0755	edit dl rm
numa_faults.txt	1710	0644	edit dl rm
overcommit.meta	584	0644	edit dl rm
overcommit.stp	217	0755	edit dl rm
pfaults.meta	744	0644	edit dl rm
pfaults.stp	875	0755	edit dl rm
pfaults.txt	558	0644	edit dl rm
vm.tracepoints.meta	608	0644	edit dl rm
vm.tracepoints.stp	414	0755	edit dl rm
vm.tracepoints.txt	557	0644	edit dl rm

Edit: /usr/share/systemtap/examples/memory/kmalloc-top (3888B)

#!/usr/bin/perl
#
# This script accumulates the execution paths of all calls to kmalloc
# in the kernel.  On Ctrl-C (or exit of the command provided by -c option),
# it sorts, filters and displays them on
# stdout.
#
# The -e (exclude) option can be used to specify a comma-separated list
# - any stack with contents matching any of the items in the list will
# be excluded from the output.
#
# The -m (min) option can be used to specify the minimum number of
# occurrences a stack needs to be included in the output.
#
# The -t (top) option can be used to specify printing only the 
# top N stack traces.
#
# The -c (command) option runs starts the command and script
# only runs for the duration of the command.
#
# The -o (options) option passes the options to systemap.
#
# Usage: ./kmalloc-top [-m min] [-e exclude list] [-t top_n] [-c command]
#           [-o options]
# Ctrl-c

use Getopt::Std;

my $kmalloc_stacks;
my $total_kmallocs;
my $filtered_kmallocs;
my $sorted_stacks;
my $first_n = 1000000000;
my $min_count = 1;
my $exclude;
my $options;

$SIG{INT} = \&sigint_handler;

getopts('c:e:m:t:o:');

if ($opt_e) {
    $exclude = join('|', split(/,/, $opt_e));
    print "Will exclude stacks containing: $exclude\n";
}

if ($opt_t) {
    $first_n = $opt_t;
    print "Will print only the top $first_n stacks.\n";
}

if ($opt_m) {
    $min_count = $opt_m;
}

if ($opt_c) {
    $command="-c \"$opt_c\""
}

if ($opt_o) {
    $options=$opt_o
}

print "Will print stacks with counts >= $min_count.\n";
print STDERR "Press Ctrl-C to stop.\n";

#The systemtap script that instruments the kmalloc
$script="
global kmalloc_stack

probe kernel.function(\"__kmalloc\") { kmalloc_stack[backtrace()]++ }

probe timer.ms(100), end
{
  foreach (stack in kmalloc_stack) {
    printf(\"<hashkey>\\n\")
    print_syms(stack) 
    printf(\"</hashkey>\\n\")
    printf(\"<hashval>%d</hashval>\\n\", kmalloc_stack[stack])
  }
  delete kmalloc_stack
}
";

open STREAM, "stap $options -e '$script' $command|" or die "Couldn't get output stream $!";

while (<STREAM>) {
    if (/<hashval>(.*?)<\/hashval>/) {
	update_hash($key, $1);
	$key = "";
    } elsif ($_ !~ (/<hashkey>|<\/hashkey>/))  {
	$key .= $_;
    }
}

$num_keys_before_filtering = scalar keys %kmalloc_stacks;
$total_kmallocs = count_kmallocs();
filter_stacks();
sort_stacks();
top_stacks();
sort_stacks();
$num_keys_after_filtering = scalar keys %kmalloc_stacks;
$filtered_kmallocs = count_kmallocs();
summarize();
exit();

sub update_hash
{
    my($key, $val) = @_;
    $kmalloc_stacks{$key} += $val;
}

sub filter_stacks
{
    while (($stack, $count) = each %kmalloc_stacks) {
	if ($count < $min_count) {
	    delete $kmalloc_stacks{$stack};
	} elsif ($exclude && $stack =~ /$exclude/) {
	    delete $kmalloc_stacks{$stack};
	}
    }
}

sub top_stacks
{
    $count=0;
    foreach $stack(@sorted_stacks) {
	$count+=1;
	if ($count > $first_n) {
	    delete $kmalloc_stacks{$stack};
	}
    }
}

sub sort_stacks
{
    @sorted_stacks = sort { $kmalloc_stacks{$b} <=> $kmalloc_stacks{$a} } keys %kmalloc_stacks;
}

sub count_kmallocs {
    $count = 0;
    foreach $stack(%kmalloc_stacks) {
	$count += $kmalloc_stacks{$stack};
    }
    return $count;
}

sub summarize {
    print "\n";
    foreach $stack(@sorted_stacks) {
	print "This path seen $kmalloc_stacks{$stack} times:\n$stack\n";
    }

if ($total_kmallocs > 0) {
	$percent = ($filtered_kmallocs)*100/$total_kmallocs;
    } else {
	$percent = 0;
    }
    print "Num stacks before filtering: $num_keys_before_filtering\n";
    print "Num stacks after filtering: $num_keys_after_filtering\n";
    print "Total kmallocs (before filtering): $total_kmallocs\n";
    print "Total kmallocs (after filtering): $filtered_kmallocs\n";
    print "The filter stacks have $percent of the total kmallocs\n";

close(STREAM);
}

sub sigint_handler
{
    system("pkill kmalloc-stacks");
}

cmd: