Re: [PATCH 4/6] perf annotate-data: Bound the member nesting recursion

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Fri, Sep 25, 2026 at 05:43:43PM +0200, Arnaldo Carvalho de Melo wrote:
> On Fri, Sep 25, 2026 at 08:39:21AM -0700, Namhyung Kim wrote:
> > On Fri, Sep 25, 2026 at 05:06:55PM +0200, Arnaldo Carvalho de Melo wrote:
> > > +++ b/tools/perf/util/annotate-data.h
> > > @@ -61,6 +61,9 @@ struct annotated_member {
> > >  	int size;
> > >  	bool is_union;
> > >  	bool is_flex_array;
> > > +	unsigned int depth;
> > > +	/* Children not expanded because the nesting limit was reached */
> > > +	bool truncated;

> > Nit: it'd be better to switch the order of the last two fields to reduce
> > the padding.
 
> I should have used pahole... 8-)

MAX_MEMBER_DEPTH is 32, so we can make it an u8, did it:

⬢ [acme@toolbx perf-tools-next]$ pahole -C annotated_member ~/bin/perf
struct annotated_member {
	struct list_head           node;                 /*     0    16 */
	struct list_head           children;             /*    16    16 */
	char *                     type_name;            /*    32     8 */
	char *                     var_name;             /*    40     8 */
	int                        offset;               /*    48     4 */
	int                        size;                 /*    52     4 */
	_Bool                      is_union;             /*    56     1 */
	_Bool                      is_flex_array;        /*    57     1 */
	_Bool                      truncated;            /*    58     1 */
	u8                         depth;                /*    59     1 */

	/* size: 64, cachelines: 1, members: 10 */
	/* padding: 4 */
};

⬢ [acme@toolbx perf-tools-next]$

- Arnaldo