acl: Fix RTE_ACL_RULE_SZ macro definition
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Commit Message
From: Levend Sayar <levendsayar@gmail.com>
Signed-off-by: Levend Sayar <levendsayar@gmail.com>
---
lib/librte_acl/rte_acl.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Comments
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
>
>
From: Levend Sayar <levendsayar@gmail.com>
Sent: Tuesday, July 7, 2020 4:25 PM
To: Ananyev, Konstantin <konstantin.ananyev@intel.com>
Cc: dev@dpdk.org
Subject: Re: [PATCH] acl: Fix RTE_ACL_RULE_SZ macro definition
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[];
}
[KA] Yes.
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;
[KA] I don’t think so.
You forgot about possible gaps between members of rte_acl_rule.
Let say for 64 bit target it would be a 4B gap between ‘data’ and ‘field’.
So, for:
RTE_ACL_RULE_DEF(xz, 1);
sizeof(struct xz) == RTE_ACL_RULE_SZ(1) == 32
After changes you suggest
RTE_ACL_RULE_SZ(1) == 28 != sizeof(struct xz)
Which is wrong.
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<mailto:konstantin.ananyev@intel.com>> wrote:
> From: Levend Sayar <levendsayar@gmail.com<mailto: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<mailto: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
Yes you are totally right.
I overlooked the alignment of struct components.
Sorry for that.
But imho, not to have such confusions,
Another define can be added such as
#define RTE_ACL_RULE_SIZE(xz) sizeof(struct xz)
Thanks for your time.
Best,
Levend
On Tue, Jul 7, 2020 at 7:45 PM Ananyev, Konstantin <
konstantin.ananyev@intel.com> wrote:
>
>
>
>
> *From:* Levend Sayar <levendsayar@gmail.com>
> *Sent:* Tuesday, July 7, 2020 4:25 PM
> *To:* Ananyev, Konstantin <konstantin.ananyev@intel.com>
> *Cc:* dev@dpdk.org
> *Subject:* Re: [PATCH] acl: Fix RTE_ACL_RULE_SZ macro definition
>
>
>
> 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[];
>
> }
>
>
>
> [KA] Yes.
>
>
>
> 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;
>
>
>
> [KA] I don’t think so.
>
> You forgot about possible gaps between members of rte_acl_rule.
>
> Let say for 64 bit target it would be a 4B gap between ‘data’ and ‘field’.
>
> So, for:
>
> RTE_ACL_RULE_DEF(xz, 1);
>
>
>
> sizeof(struct xz) == RTE_ACL_RULE_SZ(1) == 32
>
>
>
> After changes you suggest
>
> RTE_ACL_RULE_SZ(1) == 28 != sizeof(struct xz)
>
> Which is wrong.
>
>
>
> 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
>
>
@@ -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.*/