Re: [dpdk-dev] [PATCH] acl: Fix RTE_ACL_RULE_SZ macro definition

[Levend Sayar <levendsayar@gmail.com>]

Sure.
I am really sorry for not being verbose enough.

From lib/librte_acl/rte_acl.h

#define RTE_ACL_RULE_DEF(name, fld_num) struct name {\
    struct rte_acl_rule_data data;               \
    struct rte_acl_field field[fld_num];         \
}

RTE_ACL_RULE_DEF(rte_acl_rule,);

When you put the definition in-place, above line means :

struct rte_acl_rule {
   struct rte_acl_rule_data data;
   struct rte_acl_field field[];
}

There is another define to get the size of an acl rule such as

#define RTE_ACL_RULE_SZ(fld_num)    \
    (sizeof(struct rte_acl_rule) + sizeof(struct rte_acl_field) * (fld_num))

So the above definition gets the size of a "struct rte_acl_rule" which has
fld_num fields.
which must be
*sizeof (struct rte_acl_rule_data) *+ (sizeof(struct rte_acl_field) *
fld_num)

Because it adds up the sizes of struct components;

But according to the current RTE_ACL_RULE_SZ, it is

*sizeof (struct rte_acl_rule)* + (sizeof(struct rte_acl_field) * fld_num)

So my patch only changes the part that I underlined.

sizeof (struct rte_acl_rule) = 16;
sizeof (struct rte_acl_rule_data) = 12;

Best,
Levend


On Tue, Jul 7, 2020 at 3:42 PM Ananyev, Konstantin <
konstantin.ananyev@intel.com> wrote:

>
> > From: Levend Sayar <levendsayar@gmail.com>
>
> Could you provide some explanation:
> What do you think is wrong with current version and why,
> and what your fix does.
>
> >
> > Signed-off-by: Levend Sayar <levendsayar@gmail.com>
> > ---
> >  lib/librte_acl/rte_acl.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/lib/librte_acl/rte_acl.h b/lib/librte_acl/rte_acl.h
> > index aa22e70c6..d34fdbc0e 100644
> > --- a/lib/librte_acl/rte_acl.h
> > +++ b/lib/librte_acl/rte_acl.h
> > @@ -116,7 +116,7 @@ struct rte_acl_rule_data {
> >  RTE_ACL_RULE_DEF(rte_acl_rule,);
> >
> >  #define      RTE_ACL_RULE_SZ(fld_num)        \
> > -     (sizeof(struct rte_acl_rule) + sizeof(struct rte_acl_field) *
> (fld_num))
> > +     (sizeof(struct rte_acl_rule_data) + sizeof(struct rte_acl_field) *
> (fld_num))
> >
> >
> >  /** Max number of characters in name.*/
> > --
> > 2.27.0
>
>