Script to grab asm output and look for heavy stack (ab)users.

Could be improved a bit by having it take a list of files as args and
running objdump and then preceding each line with the filename, so we can
run it on modules more easily than having a shell script call a perl script...

diff --git a/lustre/tests/checkstack.pl b/lustre/tests/checkstack.pl
new file mode 100644 (file)
index 0000000..9c0d097
--- /dev/null
+++ b/lustre/tests/checkstack.pl
@@ -0,0 +1,92 @@
+#!/usr/bin/perl
+
+#      Check the stack usage of functions
+#
+#      Copyright Joern Engel <joern@wh.fh-wedel.de>
+#      Inspired by Linus Torvalds
+#      Original idea maybe from Keith Owens
+#
+#      Usage:
+#      objdump -d vmlinux | checkstack.pl <arch>
+#
+#      find <moduledir> -name "*.o" | while read M; do
+#              objdump -d $M | perl ~/checkstack.pl <arch> | \
+#                      sed "s/^/`basename $M`: /" ; done | \
+#      awk '/esp/ { print $5, $2, $4 }' | sort -nr
+#
+#      TODO :  Port to all architectures (one regex per arch)
+#              Speed this puppy up
+
+# check for arch
+# 
+# $re is used for three matches:
+# $& (whole re) matches the complete objdump line with the stack growth
+# $1 (first bracket) matches the code that will be displayed in the output
+# $2 (second bracket) matches the size of the stack growth
+#
+# use anything else and feel the pain ;)
+{
+       my $arch = shift;
+       $x      = "[0-9a-f]";   # hex character
+       $xs     = "[0-9a-f ]";  # hex character or space
+       if ($arch =~ /^i[3456]86$/) {
+               #c0105234:       81 ec ac 05 00 00       sub    $0x5ac,%esp
+               $re = qr/^.*(sub/s\$(0x$x{3,5}),\%esp)$/o;
+       } elsif ($arch =~ /^ia64$/) {
+               #                                        adds r12=-384,r12
+               $re = qr/.*(adds/sr12=-($x{3,5}),r12)/o;
+       } elsif ($arch =~ /^ppc$/) {
+               #c00029f4:       94 21 ff 30     stwu    r1,-208(r1)
+               $re = qr/.*(stwu/sr1,-($x{3,5})\(r1\))/o;
+       } elsif ($arch =~ /^s390x?$/) {
+               #   11160:       a7 fb ff 60             aghi   %r15,-160
+               $re = qr/.*(ag?hi.*\%r15,-(([0-9]{2}|[3-9])[0-9]{2}))/o;
+       } else {
+               print("wrong or unknown architecture\n");
+               exit
+       }
+}
+
+sub bysize($) {
+       ($asize = $a) =~ s/$re/\2/;
+       ($bsize = $b) =~ s/$re/\2/;
+       $bsize <=> $asize
+}
+
+#
+# main()
+#
+$funcre = qr/^$x* \<(.*)\>:$/;
+while ($line = <STDIN>) {
+       if ($line =~ m/$funcre/) {
+               ($func = $line) =~ s/$funcre/\1/;
+               chomp($func);
+       }
+
+       if ($line =~ m/$re/) {
+               (my $addr = $line) =~ s/^($xs{8}).*/0x\1/o;
+               chomp($addr);
+
+               my $intro = "$addr $func:";
+               my $padlen = 56 - length($intro);
+               while ($padlen > 0) {
+                       $intro .= '     ';
+                       $padlen -= 8;
+               }
+               (my $code = $line) =~ s/$re/\1/;
+
+               $stack[@stack] = "$intro $code";
+       }
+}
+
+@sortedstack = sort bysize @stack;
+
+foreach $i (@sortedstack) {
+       print("$i");
+}
+--
+Andreas Dilger
+http://sourceforge.net/projects/ext2resize/
+http://www-mddsp.enel.ucalgary.ca/People/adilger/
+
+