path: root/scripts/stackdelta
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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-08 14:23:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-08 14:23:13 -0700
commitd9241b22b58e012f26dd2244508d9f4837402af0 (patch)
treee8359d16b76e0c109d4bbaccf093765c373d9f24 /scripts/stackdelta
parentMerge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild (diff)
parentdeb-pkg: add source package (diff)
Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull misc kbuild updates from Michal Marek: - deb-pkg: + module signing fix + dtb files are added to the package + do not require `hostname -f` to work during build + make deb-pkg generates a source package, bindeb-pkg has been added to only generate the binary package - rpm-pkg packages /lib/modules as well - new coccinelle patch and updates to existing ones - new stackusage & stackdelta script to collect and compare stack usage info (using gcc's -fstack-usage) - make tags understands trace_*_rcuidle() macros - .gitignore updates, misc cleanups * 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (27 commits) deb-pkg: add source package package/Makefile: move source tar creation to a function scripts: add stackdelta script kbuild: remove *.su files generated by -fstack-usage .gitignore: add *.su pattern scripts: add stackusage script kbuild: avoid listing /lib/modules in kernel spec file fallback to hostname in scripts/package/builddeb coccinelle: api: extend spatch for dropping unnecessary owner deb-pkg: simplify directory creation scripts/tags.sh: Include trace_*_rcuidle() in tags scripts/package/Makefile: rpmbuild is needed for rpm targets Kbuild: Add ID files to .gitignore gitignore: Add MIPS vmlinux.32 to the list coccinelle: simple_return: Add a blank line coccinelle: irqf_oneshot.cocci: Improve the generated commit log coccinelle: api: add vma_pages.cocci scripts/coccinelle/misc/irqf_oneshot.cocci: Fix grammar scripts/coccinelle/misc/semicolon.cocci: Use imperative mood coccinelle: simple_open: Use imperative mood ...
Diffstat (limited to 'scripts/stackdelta')
1 files changed, 59 insertions, 0 deletions
diff --git a/scripts/stackdelta b/scripts/stackdelta
new file mode 100755
index 000000000000..48eabf2f48f8
--- /dev/null
+++ b/scripts/stackdelta
@@ -0,0 +1,59 @@
+# Read two files produced 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.
+# A third possibility is for sorting by delta, but that can be
+# achieved by piping to sort -k5,5g.
+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 $func =~ m/^[0-9]+$/;
+ $func =~ s/\..*$//;
+ # Line numbers are likely to change; strip those.
+ $file =~ s/:[0-9]+$//;
+ $su{"${file}\t${func}"} = {size => $size, type => $type};
+ }
+ close($fh);
+ return \%su;
+@ARGV == 2
+ or die "usage: $0 <old> <new>";
+my $old = read_stack_usage_file($ARGV[0]);
+my $new = read_stack_usage_file($ARGV[1]);
+my @common = sort grep {exists $new->{$_}} keys %$old;
+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;
+ }