[v4,1/2] mbuf: add function returning default buffer address
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Commit Message
This patch introduces two new functions - rte_mbuf_buf_addr() and
rte_mbuf_data_addr_default().
rte_mbuf_buf_addr() reutrns the default buffer address of given mbuf which
comes after mbuf structure and private data.
rte_mbuf_data_addr_default() returns the default address of mbuf data
taking the headroom into account.
Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
---
Please ignore v3, there were errors with some compilers.
v4:
* fix compilation error due to the experimental tag
* add warning of experimental tag to the comments
v3:
* rename functions
v2:
* initial implementation
lib/librte_mbuf/rte_mbuf.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
Comments
On Thu, Jan 10, 2019 at 02:40:29PM -0800, Yongseok Koh wrote:
> This patch introduces two new functions - rte_mbuf_buf_addr() and
> rte_mbuf_data_addr_default().
>
> rte_mbuf_buf_addr() reutrns the default buffer address of given mbuf which
> comes after mbuf structure and private data.
>
> rte_mbuf_data_addr_default() returns the default address of mbuf data
> taking the headroom into account.
>
> Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
On Thu, Jan 10, 2019 at 11:40 PM Yongseok Koh <yskoh@mellanox.com> wrote:
> This patch introduces two new functions - rte_mbuf_buf_addr() and
> rte_mbuf_data_addr_default().
>
> rte_mbuf_buf_addr() reutrns the default buffer address of given mbuf which
>
returns
> comes after mbuf structure and private data.
>
> rte_mbuf_data_addr_default() returns the default address of mbuf data
> taking the headroom into account.
>
> Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
> ---
>
> Please ignore v3, there were errors with some compilers.
>
> v4:
> * fix compilation error due to the experimental tag
> * add warning of experimental tag to the comments
>
> v3:
> * rename functions
>
> v2:
> * initial implementation
>
> lib/librte_mbuf/rte_mbuf.h | 46
> ++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 46 insertions(+)
>
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index bc562dc8a9..5787616999 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -788,8 +788,54 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi)
> }
>
> /**
> + * Return the default buffer address of the mbuf.
>
Nit: missed it... s/default //
+ *
> + * @warning
> + * @b EXPERIMENTAL: This API may change without prior notice.
> + * This will be used by rte_mbuf_to_baddr() which has redundant code once
> + * experimental tag is removed.
>
Good point.
I wonder if we have a "todolist" for release n+2 so that we don't forget
about such things to do.
Thomas ?
+ *
> + * @param mb
> + * The pointer to the mbuf.
> + * @param mp
> + * The pointer to the mempool of the mbuf.
> + * @return
> + * The pointer of the mbuf buffer.
> + */
> +static inline char * __rte_experimental
> +rte_mbuf_buf_addr(struct rte_mbuf *mb, struct rte_mempool *mp)
> +{
> + char *buffer_addr;
> +
> + buffer_addr = (char *)mb + sizeof(*mb) + rte_pktmbuf_priv_size(mp);
> + return buffer_addr;
> +}
>
Nit:
+ return (char *)mb + sizeof(*mb) + rte_pktmbuf_priv_size(mp);
+
> +/**
> + * Return the default address of the beginning of the mbuf data.
> + *
> + * @warning
> + * @b EXPERIMENTAL: This API may change without prior notice.
> + *
> + * @param mb
> + * The pointer to the mbuf.
> + * @return
> + * The pointer of the beginning of the mbuf data.
> + */
> +static inline char * __rte_experimental
> +rte_mbuf_data_addr_default(struct rte_mbuf *mb)
> +{
> + return rte_mbuf_buf_addr(mb, mb->pool) + RTE_PKTMBUF_HEADROOM;
> +}
> +
> +/**
> * Return the buffer address embedded in the given mbuf.
> *
> + * @note: Accessing mempool pointer of a mbuf is expensive because the
> + * pointer is stored in the 2nd cache line of mbuf. If mempool is known,
> it
> + * is better not to reference the mempool pointer in mbuf but calling
> + * rte_mbuf_buf_addr() would be more efficient.
> + *
> * @param md
> * The pointer to the mbuf.
> * @return
> --
> 2.11.0
>
>
Thanks Yongseok.
Reviewed-by: David Marchand <david.marchand@redhat.com>
On Fri, Jan 11, 2019 at 9:11 AM David Marchand <david.marchand@redhat.com>
wrote:
> On Thu, Jan 10, 2019 at 11:40 PM Yongseok Koh <yskoh@mellanox.com> wrote:
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
>
>> index bc562dc8a9..5787616999 100644
>> --- a/lib/librte_mbuf/rte_mbuf.h
>> +++ b/lib/librte_mbuf/rte_mbuf.h
>> @@ -788,8 +788,54 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi)
>> }
>>
>> /**
>> + * Return the default buffer address of the mbuf.
>>
>
> Nit: missed it... s/default //
>
> + *
>> + * @warning
>> + * @b EXPERIMENTAL: This API may change without prior notice.
>> + * This will be used by rte_mbuf_to_baddr() which has redundant code once
>> + * experimental tag is removed.
>>
>
> Good point.
> I wonder if we have a "todolist" for release n+2 so that we don't forget
> about such things to do.
> Thomas ?
>
Maybe we could have something explicit in rte_mbuf_to_baddr that would
avoid it "inherits" the experimental tag.
@@ -844,9 +844,13 @@ struct rte_mbuf_ext_shared_info {
static inline char *
rte_mbuf_to_baddr(struct rte_mbuf *md)
{
+#ifdef ALLOW_EXPERIMENTAL_API
+ return rte_mbuf_buf_addr(md, md->pool);
+#else
char *buffer_addr;
buffer_addr = (char *)md + sizeof(*md) +
rte_pktmbuf_priv_size(md->pool);
return buffer_addr;
+#endif
}
/**
11/01/2019 09:11, David Marchand:
> On Thu, Jan 10, 2019 at 11:40 PM Yongseok Koh <yskoh@mellanox.com> wrote:
> > + * @warning
> > + * @b EXPERIMENTAL: This API may change without prior notice.
> > + * This will be used by rte_mbuf_to_baddr() which has redundant code once
> > + * experimental tag is removed.
>
> Good point.
> I wonder if we have a "todolist" for release n+2 so that we don't forget
> about such things to do.
> Thomas ?
If code comment is not enough, we can use Bugzilla.
On Fri, Jan 11, 2019 at 09:32:52AM +0100, David Marchand wrote:
> On Fri, Jan 11, 2019 at 9:11 AM David Marchand <david.marchand@redhat.com>
> wrote:
>
> > On Thu, Jan 10, 2019 at 11:40 PM Yongseok Koh <yskoh@mellanox.com> wrote:
> > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> >
> >> index bc562dc8a9..5787616999 100644
> >> --- a/lib/librte_mbuf/rte_mbuf.h
> >> +++ b/lib/librte_mbuf/rte_mbuf.h
> >> @@ -788,8 +788,54 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi)
> >> }
> >>
> >> /**
> >> + * Return the default buffer address of the mbuf.
> >>
> >
> > Nit: missed it... s/default //
Okay
> >
> > + *
> >> + * @warning
> >> + * @b EXPERIMENTAL: This API may change without prior notice.
> >> + * This will be used by rte_mbuf_to_baddr() which has redundant code once
> >> + * experimental tag is removed.
> >>
> >
> > Good point.
> > I wonder if we have a "todolist" for release n+2 so that we don't forget
> > about such things to do.
> > Thomas ?
> >
>
> Maybe we could have something explicit in rte_mbuf_to_baddr that would
> avoid it "inherits" the experimental tag.
>
> @@ -844,9 +844,13 @@ struct rte_mbuf_ext_shared_info {
> static inline char *
> rte_mbuf_to_baddr(struct rte_mbuf *md)
> {
> +#ifdef ALLOW_EXPERIMENTAL_API
> + return rte_mbuf_buf_addr(md, md->pool);
> +#else
> char *buffer_addr;
> buffer_addr = (char *)md + sizeof(*md) +
> rte_pktmbuf_priv_size(md->pool);
> return buffer_addr;
> +#endif
I like it, so that we can't forget to change it.
Yongseok
@@ -788,8 +788,54 @@ rte_mbuf_from_indirect(struct rte_mbuf *mi)
}
/**
+ * Return the default buffer address of the mbuf.
+ *
+ * @warning
+ * @b EXPERIMENTAL: This API may change without prior notice.
+ * This will be used by rte_mbuf_to_baddr() which has redundant code once
+ * experimental tag is removed.
+ *
+ * @param mb
+ * The pointer to the mbuf.
+ * @param mp
+ * The pointer to the mempool of the mbuf.
+ * @return
+ * The pointer of the mbuf buffer.
+ */
+static inline char * __rte_experimental
+rte_mbuf_buf_addr(struct rte_mbuf *mb, struct rte_mempool *mp)
+{
+ char *buffer_addr;
+
+ buffer_addr = (char *)mb + sizeof(*mb) + rte_pktmbuf_priv_size(mp);
+ return buffer_addr;
+}
+
+/**
+ * Return the default address of the beginning of the mbuf data.
+ *
+ * @warning
+ * @b EXPERIMENTAL: This API may change without prior notice.
+ *
+ * @param mb
+ * The pointer to the mbuf.
+ * @return
+ * The pointer of the beginning of the mbuf data.
+ */
+static inline char * __rte_experimental
+rte_mbuf_data_addr_default(struct rte_mbuf *mb)
+{
+ return rte_mbuf_buf_addr(mb, mb->pool) + RTE_PKTMBUF_HEADROOM;
+}
+
+/**
* Return the buffer address embedded in the given mbuf.
*
+ * @note: Accessing mempool pointer of a mbuf is expensive because the
+ * pointer is stored in the 2nd cache line of mbuf. If mempool is known, it
+ * is better not to reference the mempool pointer in mbuf but calling
+ * rte_mbuf_buf_addr() would be more efficient.
+ *
* @param md
* The pointer to the mbuf.
* @return