Re: [PATCH bpf-next v3 3/4] x86: implement per-function metadata storage for x86

[Steven Rostedt]

On Mon,  3 Mar 2025 14:53:44 +0800
Menglong Dong <menglong8.dong@xxxxxxxxx> wrote:

> In the third case, we make the kernel function 32 bytes aligned, and there
> will be 32 bytes padding before the functions. According to my testing,
> the text size didn't increase on this case, which is weird.
> 
> With 16-bytes padding:
> 
> -rwxr-xr-x 1 401190688  x86-dev/vmlinux*
> -rw-r--r-- 1    251068  x86-dev/vmlinux.a
> -rw-r--r-- 1 851892992  x86-dev/vmlinux.o
> -rw-r--r-- 1  12395008  x86-dev/arch/x86/boot/bzImage
> 
> With 32-bytes padding:
> 
> -rwxr-xr-x 1 401318128 x86-dev/vmlinux*
> -rw-r--r-- 1    251154 x86-dev/vmlinux.a
> -rw-r--r-- 1 853636704 x86-dev/vmlinux.o
> -rw-r--r-- 1  12509696 x86-dev/arch/x86/boot/bzImage

Use the "size" command to see the differences in sizes and not the file size.

$ size vmlinux
   text    data     bss     dec     hex filename
36892658        9798658 16982016        63673332        3cb93f4 vmlinux

-- Steve