From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932770AbbFUBLj (ORCPT ); Sat, 20 Jun 2015 21:11:39 -0400 Received: from mail-lb0-f180.google.com ([209.85.217.180]:36383 "EHLO mail-lb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755641AbbFUBLK (ORCPT ); Sat, 20 Jun 2015 21:11:10 -0400 From: Rasmus Villemoes To: Michal Marek Cc: linux-kbuild@vger.kernel.org, Rasmus Villemoes , linux-kernel@vger.kernel.org Subject: [RFC 4/4] scripts: add stackdelta script Date: Sun, 21 Jun 2015 03:10:46 +0200 Message-Id: <1434849046-19920-5-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1434849046-19920-1-git-send-email-linux@rasmusvillemoes.dk> References: <1434849046-19920-1-git-send-email-linux@rasmusvillemoes.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds a simple perl script for reading two files as produced by the stackusage script and computing the changes in stack usage. For example: $ scripts/stackusage -o /tmp/old.su -- CC=gcc-4.7 -j8 fs/ext4/ $ scripts/stackusage -o /tmp/new.su -- CC=gcc-5.0 -j8 fs/ext4/ $ scripts/stackdelta /tmp/{old,new}.su | sort -k5,5g shows that gcc 5.0 generally produces less stack-hungry code than gcc 4.7. Obviously, the script can also be used for measuring the effect of commits, .config tweaks or whatnot. Signed-off-by: Rasmus Villemoes --- scripts/stackdelta | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100755 scripts/stackdelta diff --git a/scripts/stackdelta b/scripts/stackdelta new file mode 100755 index 000000000000..18417098a378 --- /dev/null +++ b/scripts/stackdelta @@ -0,0 +1,55 @@ +#!/usr/bin/perl + +# Read two files producesd by the stackusage script, and show the +# delta between them. +# +# Currently, only shows changes for functions listed in both files. We +# could add an option to show also functions which have vanished or +# appeared (which would often be due to gcc making other inlining +# decisions). +# +# Another possible option would be a minimum absolute value for the +# delta. + +sub read_stack_usage_file { + my %su; + my $f = shift; + open(my $fh, '<', $f) + or die "cannot open $f: $!"; + while (<$fh>) { + chomp; + my ($file, $func, $size, $type) = split; + # Old versions of gcc (at least 4.7) have an annoying quirk in + # that a (static) function whose name has been changed into + # for example ext4_find_unwritten_pgoff.isra.11 will show up + # in the .su file with a name of just "11". Since such a + # numeric suffix is likely to change across different + # commits/compilers/.configs or whatever else we're trying to + # tweak, we can't really track those functions, so we just + # silently skip them. + # + # Newer gcc (at least 5.0) report the full name, so again, + # since the suffix is likely to change, we strip it. + next if $func =~ m/^[0-9]+$/; + $func =~ s/\..*$//; + $su{"${file}\t${func}"} = {size => $size, type => $type}; + } + close($fh); + return \%su; +} + +@ARGV == 2 + or die "usage: $0 "; + +my $old = read_stack_usage_file($ARGV[0]); +my $new = read_stack_usage_file($ARGV[1]); +my @common = grep {exists $new->{$_}} keys %$old; +print join(",", keys %old) . "\n"; +for (@common) { + my $x = $old->{$_}{size}; + my $y = $new->{$_}{size}; + my $delta = $y - $x; + if ($delta) { + printf "%s\t%d\t%d\t%+d\n", $_, $x, $y, $delta; + } +} -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/