#!/usr/bin/perl

my %lastdata=();
my $count=0;
my $cmd="dmsetup status --target cache " . join(" ", @ARGV);
while(1) {
	printf("device           mpct  cpct  r_hit r_miss  rpct  w_hit w_miss  wpct prm dem dirt\n") if scalar(@ARGV) != 1 || !$count++;

	my @alldata=`$cmd`;
	foreach my $data(@alldata) {
		my $dev;
		if(scalar(@ARGV) == 1) {
			$dev=$ARGV[0];
			$dev =~ s/^.+\/[^\/]+$//;
		} else {
			$data =~ s/^(\S+)://;
			$dev=$1;
		}
		if(length($dev) > 15) {
			$dev=substr($dev,0,15);
		}

		$data =~ s/^[0-9 ]+ cache //;
		#print $data;
		chomp $data;
		my @data=split / /,$data;

		my @curdata=();


		# From what I can tell:
		# Read hits come from SSD only
		# Read misses come from HDD
		# Promotions cause SSD writes
		# Demotions do nothing
		# Dirty blocks need writeback

		# Data line:
		#metabsize metaused/total databsize dataused/total rhit rmiss whit wmiss demotions promotions dirty nfeature feature ncore ncorekeyval corekey0 coreval0 ... policyname npolicyarg policykey0 policyarg0 ... 
		#8 1631/51200 256 162410/819200 6361491 22705424 50094334 10653259 0 162410 0 1 writeback 2 migration_threshold 2048 mq 10 random_threshold 4 sequential_threshold 512 discard_promote_adjustment 1 read_promote_adjustment 4 write_promote_adjustment 8
		if(!scalar(@{$lastdata{$dev}})) {
			push @curdata, eval "($data[1]) * 100";
			push @curdata, eval "($data[3]) * 100";
			push @curdata, $data[4];
			push @curdata, $data[5];
			push @curdata, $data[6];
			push @curdata, $data[7];
			push @curdata, $data[8];
			push @curdata, $data[9];
			push @curdata, $data[10];
		} else {
			push @curdata, eval "($data[1]) * 100";
			push @curdata, eval "($data[3]) * 100";
			push @curdata, $data[4]-$lastdata{$dev}[4];
			push @curdata, $data[5]-$lastdata{$dev}[5];
			push @curdata, $data[6]-$lastdata{$dev}[6];
			push @curdata, $data[7]-$lastdata{$dev}[7];
			push @curdata, $data[8]-$lastdata{$dev}[8];
			push @curdata, $data[9]-$lastdata{$dev}[9];
			push @curdata, $data[10];
		}
		@{$lastdata{$dev}}=@data;

		printf("%-15s %5.1f %5.1f % 6d % 6d %5.1f % 6d % 6d %5.1f %3d %3d %4d\n", $dev, $curdata[0], $curdata[1], $curdata[2], $curdata[3], (($curdata[3]||$curdata[2])?100*$curdata[2]/($curdata[3]+$curdata[2]):0), $curdata[4], $curdata[5], (($curdata[5]||$curdata[4])?100*$curdata[4]/($curdata[5]+$curdata[4]):0), $curdata[6], $curdata[7], $curdata[8]);
	}
	print "\n" if scalar(@ARGV) != 1;

	$count=0 if $count>24;
	sleep 1;
}