linux-kernel - Re: [PATCH 1/4] scripts/checkstack.pl: don't display $dre as different entity

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Date:   Thu, 7 May 2020 17:12:34 +0900
From:   Masahiro Yamada <masahiroy@...nel.org>
To:     Maninder Singh <maninder1.s@...sung.com>
Cc:     "George G. Davis" <george_davis@...tor.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        a.sahrawat@...sung.com, Vaneet Narang <v.narang@...sung.com>
Subject: Re: [PATCH 1/4] scripts/checkstack.pl: don't display $dre as
 different entity

On Thu, Apr 30, 2020 at 9:50 PM Maninder Singh <maninder1.s@...sung.com> wrote:
>
> currnetly script prints stack usage for functions
> in two ways:($re and $dre)
>
> dre breaks sorting mechanism.
> 0xffffa00011f26f88 sunxi_mux_clk_setup.isra.0 [vmlinux]:Dynamic (0x140)
> ..
> 0xffffa00011f27210 sunxi_divs_clk_setup [vmlinux]:      Dynamic (0x1d0)
>
> so we can print it in decimal only.
>
> Also address before function name is changed to function
> start address rather than stack consumption address.
> Because in next patch, arm has two ways to use stack
> which can be clubbed and printed in one function only.
>
> All symbols whose stack by adding(re and dre) is greater than
> 100, will be printed.
>
> 0xffffa00011f2720c0 sunxi_divs_clk_setup [vmlinux]:     464
> ...
> 0xffffa00011f26f840 sunxi_mux_clk_setup.isra.0 [vmlinux]:320
>
> Signed-off-by: Vaneet Narang <v.narang@...sung.com>
> Signed-off-by: Maninder Singh <maninder1.s@...sung.com>
> ---
>  scripts/checkstack.pl | 52 +++++++++++++++++++++++++--------------------------
>  1 file changed, 25 insertions(+), 27 deletions(-)
>
> diff --git a/scripts/checkstack.pl b/scripts/checkstack.pl
> index 371bd17..412c459 100755
> --- a/scripts/checkstack.pl
> +++ b/scripts/checkstack.pl
> @@ -109,11 +109,28 @@ my (@stack, $re, $dre, $x, $xs, $funcre);
>  #
>  # main()
>  #
> -my ($func, $file, $lastslash);
> +my ($func, $file, $lastslash, $total_size, $addr, $intro);


$total_size is undefined for the first function.
I think 0 is implied, but is it clearer to initialize it here?

$total_size = 0;



>  while (my $line = <STDIN>) {
>         if ($line =~ m/$funcre/) {
> +               if ($total_size > 100) {
> +                       push @stack, "$intro$total_size\n";
> +               }
> +
>                 $func = $1;
> +               next if $line !~ m/^($xs*)/;

Hmm, I think this 'next' is unlikely to happen.
But, it happened, the same line would be pushed twice.

Maybe, is it better to move 'next it' above
the 'if ($total_size > 100)' check?




> +               $addr = $1;
> +               $addr =~ s/ /0/g;
> +               $addr = "0x$addr";
> +
> +               $intro = "$addr $func [$file]:";
> +               my $padlen = 56 - length($intro);
> +               while ($padlen > 0) {
> +                       $intro .= '     ';
> +                       $padlen -= 8;
> +               }
> +
> +               $total_size = 0;
>         }
>         elsif ($line =~ m/(.*):\s*file format/) {
>                 $file = $1;
> @@ -134,37 +151,18 @@ while (my $line = <STDIN>) {
>                 }
>                 next if ($size > 0x10000000);
>
> -               next if $line !~ m/^($xs*)/;
> -               my $addr = $1;
> -               $addr =~ s/ /0/g;
> -               $addr = "0x$addr";
> -
> -               my $intro = "$addr $func [$file]:";
> -               my $padlen = 56 - length($intro);
> -               while ($padlen > 0) {
> -                       $intro .= '     ';
> -                       $padlen -= 8;
> -               }
> -               next if ($size < 100);
> -               push @stack, "$intro$size\n";
> +               $total_size = $total_size + $size


For consistency, I personally prefer adding ';'
to every statement even for the last one in the block...


Is this simpler ?

                  $total_size += $size;






>         }
>         elsif (defined $dre && $line =~ m/$dre/) {
> -               my $size = "Dynamic ($1)";
> -
> -               next if $line !~ m/^($xs*)/;
> -               my $addr = $1;
> -               $addr =~ s/ /0/g;
> -               $addr = "0x$addr";
> +               my $size = $1;
>
> -               my $intro = "$addr $func [$file]:";
> -               my $padlen = 56 - length($intro);
> -               while ($padlen > 0) {
> -                       $intro .= '     ';
> -                       $padlen -= 8;
> -               }
> -               push @stack, "$intro$size\n";
> +               $size = hex($size) if ($size =~ /^0x/);
> +               $total_size = $total_size + $size



Ditto. How about this?

                  $total_size += $size;


>         }
>  }
> +if ($total_size > 100) {
> +       push @stack, "$intro$total_size\n";
> +}
>
>  # Sort output by size (last field)
>  print sort { ($b =~ /:\t*(\d+)$/)[0] <=> ($a =~ /:\t*(\d+)$/)[0] } @stack;
> --
> 1.9.1
>


--
Best Regards
Masahiro Yamada