From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: Levend Sayar <levendsayar@gmail.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] acl: Fix RTE_ACL_RULE_SZ macro definition
Date: Tue, 7 Jul 2020 16:44:58 +0000 [thread overview]
Message-ID: <BYAPR11MB3301A55C1DA7913102031C6C9A660@BYAPR11MB3301.namprd11.prod.outlook.com> (raw)
In-Reply-To: <CAGDw98n+8HPor+ZXtidbZS1KZgcaDgfgraGFbVbiFXJThmWN3A@mail.gmail.com>
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
next prev parent reply other threads:[~2020-07-07 16:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 12:26 levendsayar
2020-07-07 12:42 ` Ananyev, Konstantin
2020-07-07 15:25 ` Levend Sayar
2020-07-07 16:44 ` Ananyev, Konstantin [this message]
2020-07-07 16:59 ` Levend Sayar
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