Hi Pablo,
On 28-06-2018 17:11, De Lara Guarch, Pablo wrote:
External Email
Hi Anoob,
-----Original Message-----
From: Joseph, Anoob [mailto:anoob.jos...@caviumnetworks.com]
Sent: Thursday, June 28, 2018 3:56 AM
To: Doherty, Declan <declan.dohe...@intel.com>; De Lara Guarch, Pablo
<pablo.de.lara.gua...@intel.com>
Cc: Akhil Goyal <akhil.go...@nxp.com>; Ankur Dwivedi
<ankur.dwiv...@caviumnetworks.com>; Jerin Jacob
<jerin.ja...@caviumnetworks.com>; Narayana Prasad
<narayanaprasad.athr...@caviumnetworks.com>; dev@dpdk.org
Subject: Re: [PATCH 1/2] cryptodev: add min headroom and tailroom
requirement
Hi Declan,
Please see inline.
Thanks,
Anoob
On 26-06-2018 15:42, Doherty, Declan wrote:
External Email
On 19/06/2018 7:26 AM, Anoob Joseph wrote:
Enabling crypto devs to specify the minimum headroom and tailroom it
expects in the mbuf. For net PMDs, standard headroom has to be
honoured by applications, which is not strictly followed for crypto
devs. This
How is this done for NET PMDs, I don't see anything explicit in the
ehtdev API for specification of headroom requirements.
In rte_mbuf.h, the minimum size required for packets involved in rx/tx is
specified and that considers headroom also. Applications usually use these
default macros while creating mbufs which are involved in rx/tx.
https://git.dpdk.org/dpdk/tree/lib/librte_mbuf/rte_mbuf.h#n411
prevents crypto devs from using free space in mbuf (available as
head/tailroom) for internal requirements in crypto operations.
Addition of head/tailroom requirement will help PMDs to communicate
such requirements to the application.
The availability and use of head/tailroom is an optimization if the
hardware supports use of head/tailroom for crypto-op info. For
devices that do not support using the head/tailroom, they can
continue to operate without any performance-drop.
Is there any variations in requirements for terms headroom/tailroom on
a per algorithmic basis or is it purely for the device?
It is purely per device basis. The device can specify upper bounds for the
head/tailroom. A device that even specified the room, may not even use the
entire room in all cases. So it doesn't have to be algo specific.
Signed-off-by: Anoob Joseph <anoob.jos...@caviumnetworks.com>
---
doc/guides/rel_notes/deprecation.rst | 4 ++++
lib/librte_cryptodev/rte_cryptodev.h | 6 ++++++
2 files changed, 10 insertions(+)
diff --git a/doc/guides/rel_notes/deprecation.rst
b/doc/guides/rel_notes/deprecation.rst
index 1ce692e..a547289 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -122,3 +122,7 @@ Deprecation Notices
- Function ``rte_cryptodev_get_private_session_size()`` will be
deprecated
in 18.05, and it gets replaced with
``rte_cryptodev_sym_get_private_session_size()``.
It will be removed in 18.08.
+ - New field, ``min_headroom_req``, added in ``rte_cryptodev_info``
structure. It will be
+ added in 18.11.
+ - New field, ``min_tailroom_req``, added in ``rte_cryptodev_info``
structure. It will be
+ added in 18.11.
diff --git a/lib/librte_cryptodev/rte_cryptodev.h
b/lib/librte_cryptodev/rte_cryptodev.h
index 92ce6d4..fa944b8 100644
--- a/lib/librte_cryptodev/rte_cryptodev.h
+++ b/lib/librte_cryptodev/rte_cryptodev.h
@@ -382,6 +382,12 @@ struct rte_cryptodev_info {
unsigned max_nb_queue_pairs;
/**< Maximum number of queues pairs supported by device. */
+ uint32_t min_headroom_req;
+ /**< Minimum mbuf headroom required by device */
+
+ uint32_t min_tailroom_req;
+ /**< Minimum mbuf tailroom required by device */
I would add the word "mbuf" here, in the variable names (e.g.
min_mbuf_headroom_req),
to be more explicit.
Will revise the patch with this change.
Also, just let you know that we are currently modifying the info structure in
this release.
Therefore, I think we could make these changes in now and then you don't need
to add deprecation notices on this,
but better to add the API Change in release notes.
Will do so.
Thanks,
Anoob
