Re: [PATCH v6 08/10] perf metricgroup: Support printing metric groups for system PMUs

[John Garry]

On 07/12/2020 17:23, Arnaldo Carvalho de Melo wrote:
> > +struct metricgroup_print_sys_idata {
> > +	struct strlist *metriclist;
> > +	bool metricgroups;
> > +	char *filter;
> > +	bool raw;
> > +	bool details;
> > +	struct rblist *groups;
> > +};
> I'm doing some reorg to avoid these holes:
>
> [acme@five perf]$ pahole -C metricgroup_print_sys_idata ~/bin/perf
> struct metricgroup_print_sys_idata {
> 	struct strlist *           metriclist;           /*     0     8 */
> 	_Bool                      metricgroups;         /*     8     1 */
>
> 	/* XXX 7 bytes hole, try to pack */
>
> 	char *                     filter;               /*    16     8 */
> 	_Bool                      raw;                  /*    24     1 */
> 	_Bool                      details;              /*    25     1 */
>
> 	/* XXX 6 bytes hole, try to pack */
>
> 	struct rblist *            groups;               /*    32     8 */
>
> 	/* size: 40, cachelines: 1, members: 6 */
> 	/* sum members: 27, holes: 2, sum holes: 13 */
> 	/* last cacheline: 40 bytes */
> };
> [acme@five perf]$
>
> It ended up as:
>
> [acme@five perf]$ pahole -C metricgroup_print_sys_idata ~/bin/perf
> struct metricgroup_print_sys_idata {
> 	struct strlist *           metriclist;           /*     0     8 */
> 	char *                     filter;               /*     8     8 */
> 	struct rblist *            groups;               /*    16     8 */
> 	_Bool                      metricgroups;         /*    24     1 */
> 	_Bool                      raw;                  /*    25     1 */
> 	_Bool                      details;              /*    26     1 */
>
> 	/* size: 32, cachelines: 1, members: 6 */
> 	/* padding: 5 */
> 	/* last cacheline: 32 bytes */
> };
> [acme@five perf]$o

Hi Arnaldo,

OK, I'll be less wasteful in my struct organization.

Thanks,
John