Re: [PATCH v1 06/11] perf annotate-data: Collect global variables without name

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Jan 26, 2026 at 09:04:59PM -0500, Zecheng Li wrote:
> Previously, global_var__collect() required get_global_var_info() to
> succeed (i.e., the variable must have a symbol name) before caching a
> global variable. This prevented variables that exist in DWARF but lack
> symbol table coverage from being cached.

Do you have any example?  It's not clear to me why global variables
don't have name.

Thanks,
Namhyung

> 
> Remove the symbol table requirement since DW_OP_addr already provides
> the variable's address directly from DWARF. The symbol table lookup is
> now optional to obtain the variable name when available.
> 
> Also remove the var_offset != 0 check, which was intended to skip
> variables where the access address doesn't match the symbol start.
> The symbol table lookup is now optional and I found removing this check
> has no effect on the annotation results for both kernel and userspace
> programs.
> 
> Test results show improved annotation coverage especially for userspace
> programs with RIP-relative addressing instructions.
> 
> Signed-off-by: Zecheng Li <zli94@ncsu.edu>
> ---
>  tools/perf/util/annotate-data.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
> index 8ea3e8b024e8..970238bc81b7 100644
> --- a/tools/perf/util/annotate-data.c
> +++ b/tools/perf/util/annotate-data.c
> @@ -774,12 +774,7 @@ static void global_var__collect(struct data_loc_info *dloc)
>  			if (!dwarf_offdie(dwarf, pos->die_off, &type_die))
>  				continue;
>  
> -			if (!get_global_var_info(dloc, pos->addr, &var_name,
> -						 &var_offset))
> -				continue;
> -
> -			if (var_offset != 0)
> -				continue;
> +			get_global_var_info(dloc, pos->addr, &var_name, &var_offset);
>  
>  			global_var__add(dloc, pos->addr, var_name, &type_die);
>  		}
> -- 
> 2.52.0
>