Thank you Choroba . I tried your code and execution time has improved a lot upon parsing multiple files of the same input format.

I was more interested in the Total CPU/Memory/Storage allocation than the Overcommit ratio, So added one more section to the code .

.... some lines  ....
.......

} elsif(/^Resource Type/) {
                    $section = 'resources';
......
.....

elsif ('resources' eq $section) {
            if (my ($resource, $usage)
                = /^(CPU:|MEMORY:|ALLOCATED STORAGE:)\s+\S+\s+\S+\s+\S
++\s+\S+\s+\S+\s+\S+\s+(\S+)$/
            ) {
                $usage =~ s/%//g;
                $zone{$current_zone}{cluster}{$current_cluster}{$resou
+rce} = { usage => $usage};
            } elsif (/^$/) {
                $section = 0;
                }
......
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