diff mbox series

[v5,3/5] doc/hash: update documentation for the thash library

Message ID 1634842469-27119-4-git-send-email-vladimir.medvedkin@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers show
Series optimized Toeplitz hash implementation | expand

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Vladimir Medvedkin Oct. 21, 2021, 6:54 p.m. UTC
This patch adds documentation for the new optimized Toeplitz hash
implementation using GFNI.

Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
---
 doc/guides/prog_guide/toeplitz_hash_lib.rst | 37 +++++++++++++++++++++++++----
 doc/guides/rel_notes/release_21_11.rst      |  4 ++++
 2 files changed, 37 insertions(+), 4 deletions(-)

Comments

Thomas Monjalon Oct. 25, 2021, 5:04 p.m. UTC | #1
Vladimir, your patches are late and not perfect.
You need reviews. Please ask other maintainers to help with reviews.


21/10/2021 20:54, Vladimir Medvedkin:
> This patch adds documentation for the new optimized Toeplitz hash
> implementation using GFNI.
> 
> Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
> ---
>  doc/guides/prog_guide/toeplitz_hash_lib.rst | 37 +++++++++++++++++++++++++----
>  doc/guides/rel_notes/release_21_11.rst      |  4 ++++
>  2 files changed, 37 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/guides/prog_guide/toeplitz_hash_lib.rst b/doc/guides/prog_guide/toeplitz_hash_lib.rst
> index f916857..88b152e 100644
> --- a/doc/guides/prog_guide/toeplitz_hash_lib.rst
> +++ b/doc/guides/prog_guide/toeplitz_hash_lib.rst
> @@ -19,24 +19,53 @@ to calculate the RSS hash sum to spread the traffic among the queues.
>  Toeplitz hash function API
>  --------------------------
>  
> -There are two functions that provide calculation of the Toeplitz hash sum:
> +There are four functions that provide calculation of the Toeplitz hash sum:
>  
>  * ``rte_softrss()``
>  * ``rte_softrss_be()``
> +* ``rte_thash_gfni()``
> +* ``rte_thash_gfni_x2()``

The last function doesn't exist. I think it should be the _bulk one.

Also please squash the doc and test with the relevant code addition.
Maybe 2 patches for each implementation?
Vladimir Medvedkin Oct. 26, 2021, 8:30 p.m. UTC | #2
On 25/10/2021 19:04, Thomas Monjalon wrote:
> Vladimir, your patches are late and not perfect.
> You need reviews. Please ask other maintainers to help with reviews.
> 
> 
> 21/10/2021 20:54, Vladimir Medvedkin:
>> This patch adds documentation for the new optimized Toeplitz hash
>> implementation using GFNI.
>>
>> Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
>> ---
>>   doc/guides/prog_guide/toeplitz_hash_lib.rst | 37 +++++++++++++++++++++++++----
>>   doc/guides/rel_notes/release_21_11.rst      |  4 ++++
>>   2 files changed, 37 insertions(+), 4 deletions(-)
>>
>> diff --git a/doc/guides/prog_guide/toeplitz_hash_lib.rst b/doc/guides/prog_guide/toeplitz_hash_lib.rst
>> index f916857..88b152e 100644
>> --- a/doc/guides/prog_guide/toeplitz_hash_lib.rst
>> +++ b/doc/guides/prog_guide/toeplitz_hash_lib.rst
>> @@ -19,24 +19,53 @@ to calculate the RSS hash sum to spread the traffic among the queues.
>>   Toeplitz hash function API
>>   --------------------------
>>   
>> -There are two functions that provide calculation of the Toeplitz hash sum:
>> +There are four functions that provide calculation of the Toeplitz hash sum:
>>   
>>   * ``rte_softrss()``
>>   * ``rte_softrss_be()``
>> +* ``rte_thash_gfni()``
>> +* ``rte_thash_gfni_x2()``
> 
> The last function doesn't exist. I think it should be the _bulk one.
> 
> Also please squash the doc and test with the relevant code addition.
> Maybe 2 patches for each implementation?
> 

Good, I'll send v6

>
diff mbox series

Patch

diff --git a/doc/guides/prog_guide/toeplitz_hash_lib.rst b/doc/guides/prog_guide/toeplitz_hash_lib.rst
index f916857..88b152e 100644
--- a/doc/guides/prog_guide/toeplitz_hash_lib.rst
+++ b/doc/guides/prog_guide/toeplitz_hash_lib.rst
@@ -19,24 +19,53 @@  to calculate the RSS hash sum to spread the traffic among the queues.
 Toeplitz hash function API
 --------------------------
 
-There are two functions that provide calculation of the Toeplitz hash sum:
+There are four functions that provide calculation of the Toeplitz hash sum:
 
 * ``rte_softrss()``
 * ``rte_softrss_be()``
+* ``rte_thash_gfni()``
+* ``rte_thash_gfni_x2()``
 
-Both of these functions take the parameters:
+First two functions are scalar implementation and take the parameters:
 
 * A pointer to the tuple, containing fields extracted from the packet.
 * A length of this tuple counted in double words.
 * A pointer to the RSS hash key corresponding to the one installed on the NIC.
 
-Both functions expect the tuple to be in "host" byte order
-and a multiple of 4 bytes in length.
+Both of above mentioned _softrss_ functions expect the tuple to be in
+"host" byte order and a multiple of 4 bytes in length.
 The ``rte_softrss()`` function expects the ``rss_key``
 to be exactly the same as the one installed on the NIC.
 The ``rte_softrss_be`` function is a faster implementation,
 but it expects ``rss_key`` to be converted to the host byte order.
 
+The last two functions are vectorized implementations using
+Galois Fields New Instructions. Could be used if ``rte_thash_gfni_supported`` is true.
+They expect the tuple to be in network byte order.
+
+``rte_thash_gfni()`` calculates the hash value for a single tuple, and
+``rte_thash_gfni_x2()`` calculates for a two independent tuples in one go.
+
+``rte_thash_gfni()`` takes the parameters:
+
+* A pointer to the matrices derived from the RSS hash key using ``rte_thash_complete_matrix()``.
+* A pointer to the tuple.
+* A length of the tuple in bytes.
+
+``rte_thash_gfni_x2()`` takes the parameters:
+
+* A pointer to the matrices derived from the RSS hash key using ``rte_thash_complete_matrix()``.
+* Two tuple pointers.
+* A length of the longest tuple in bytes.
+* Two pointers on the ``uint32_t`` to write results to.
+
+``rte_thash_complete_matrix()`` is a function that calculates matrices required by
+GFNI implementations from the RSS hash key. It takes the parameters:
+
+* A pointer to the memory where the matrices will be written.
+* A pointer to the RSS hash key.
+* Length of the RSS hash key in bytes.
+
 
 Predictable RSS
 ---------------
diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
index a0ad309..d6f39fb 100644
--- a/doc/guides/rel_notes/release_21_11.rst
+++ b/doc/guides/rel_notes/release_21_11.rst
@@ -240,6 +240,10 @@  New Features
   * Added tests to verify tunnel header verification in IPsec inbound.
   * Added tests to verify inner checksum.
 
+* **Added optimized Toeplitz hash implementation.**
+
+  Added optimized Toeplitz hash implementation using Galois Fields New Instructions.
+
 
 Removed Items
 -------------