[PATCH] reorder: improve buffer structure layout

[Tyler Retzlaff]

On Fri, Apr 14, 2023 at 10:26:26AM +0100, Bruce Richardson wrote:
> On Fri, Apr 14, 2023 at 10:43:43AM +0200, Volodymyr Fialko wrote:
> > Rearrange the reorder buffer structure to prevent padding to extra one
> > cache line.
> > 
> > Current layout:
> > struct rte_reorder_buffer {
> >         char name[RTE_REORDER_NAMESIZE];
> >         uint32_t min_seqn;
> >         unsigned int memsize;
> > // -> padding to cache align (cir_buffer is also cache aligned)
> >         struct cir_buffer ready_buf;
> >         struct cir_buffer order_buf;
> >         int is_initialized;
> > // -> padding to cache align, eat whole line
> > };
> > 
> > New layout:
> > struct rte_reorder_buffer {
> >         char name[RTE_REORDER_NAMESIZE];
> >         uint32_t min_seqn;
> >         unsigned int memsize;
> >         int is_initialized;
> > // -> padding to cache align (cir_buffer is also cache aligned)
> >         struct cir_buffer ready_buf;
> >         struct cir_buffer order_buf;
> > // -> no padding
> > };
> > 
> > Signed-off-by: Volodymyr Fialko <vfialko at marvell.com>
> > ---
> 
> Acked-by: Bruce Richardson <bruce.richardson at intel.com>
> 
> >  lib/reorder/rte_reorder.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/lib/reorder/rte_reorder.c b/lib/reorder/rte_reorder.c
> > index f55f383700..7418202b04 100644
> > --- a/lib/reorder/rte_reorder.c
> > +++ b/lib/reorder/rte_reorder.c
> > @@ -46,9 +46,10 @@ struct rte_reorder_buffer {
> >  	char name[RTE_REORDER_NAMESIZE];
> >  	uint32_t min_seqn;  /**< Lowest seq. number that can be in the buffer */
> >  	unsigned int memsize; /**< memory area size of reorder buffer */
> > +	int is_initialized; /**< flag indicates that buffer was initialized */
> > +
> 
> Since we are moving it, it might be an opportunity to change it from "int"
> to "bool".

+1

> 
> >  	struct cir_buffer ready_buf; /**< temp buffer for dequeued entries */
> >  	struct cir_buffer order_buf; /**< buffer used to reorder entries */
> > -	int is_initialized;
> >  } __rte_cache_aligned;
> >  
> >  static void
> > -- 
> > 2.34.1
> >