61 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Perl
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Perl
		
	
	
		
			Executable File
		
	
	
	
	
| #!/usr/bin/env perl
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| # SPDX-License-Identifier: GPL-2.0
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| 
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| # Read two files produced by the stackusage script, and show the
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| # delta between them.
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| #
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| # Currently, only shows changes for functions listed in both files. We
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| # could add an option to show also functions which have vanished or
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| # appeared (which would often be due to gcc making other inlining
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| # decisions).
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| #
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| # Another possible option would be a minimum absolute value for the
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| # delta.
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| #
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| # A third possibility is for sorting by delta, but that can be
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| # achieved by piping to sort -k5,5g.
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| 
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| sub read_stack_usage_file {
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|     my %su;
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|     my $f = shift;
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|     open(my $fh, '<', $f)
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| 	or die "cannot open $f: $!";
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|     while (<$fh>) {
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| 	chomp;
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| 	my ($file, $func, $size, $type) = split;
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| 	# Old versions of gcc (at least 4.7) have an annoying quirk in
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| 	# that a (static) function whose name has been changed into
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| 	# for example ext4_find_unwritten_pgoff.isra.11 will show up
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| 	# in the .su file with a name of just "11". Since such a
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| 	# numeric suffix is likely to change across different
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| 	# commits/compilers/.configs or whatever else we're trying to
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| 	# tweak, we can't really track those functions, so we just
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| 	# silently skip them.
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| 	#
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| 	# Newer gcc (at least 5.0) report the full name, so again,
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| 	# since the suffix is likely to change, we strip it.
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| 	next if $func =~ m/^[0-9]+$/;
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| 	$func =~ s/\..*$//;
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| 	# Line numbers are likely to change; strip those.
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| 	$file =~ s/:[0-9]+$//;
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| 	$su{"${file}\t${func}"} = {size => $size, type => $type};
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|     }
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|     close($fh);
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|     return \%su;
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| }
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| 
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| @ARGV == 2
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|     or die "usage: $0 <old> <new>";
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| 
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| my $old = read_stack_usage_file($ARGV[0]);
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| my $new = read_stack_usage_file($ARGV[1]);
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| my @common = sort grep {exists $new->{$_}} keys %$old;
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| for (@common) {
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|     my $x = $old->{$_}{size};
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|     my $y = $new->{$_}{size};
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|     my $delta = $y - $x;
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|     if ($delta) {
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| 	printf "%s\t%d\t%d\t%+d\n", $_, $x, $y, $delta;
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|     }
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| }
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