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622f1b2f |
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18-Jan-2023 |
Daniel Machon <daniel.machon@microchip.com> |
net: dcb: add new rewrite table
Add new rewrite table and all the required functions, offload hooks and
bookkeeping for maintaining it. The rewrite table reuses the app struct,
and the entire set of app selectors. As such, some bookeeping code can
be shared between the rewrite- and the APP table.
New functions for getting, setting and deleting entries has been added.
Apart from operating on the rewrite list, these functions do not emit a
DCB_APP_EVENT when the list os modified. The new dcb_getrewr does a
lookup based on selector and priority and returns the protocol, so that
mappings from priority to protocol, for a given selector and ifindex is
obtained.
Also, a new nested attribute has been added, that encapsulates one or
more app structs. This attribute is used to distinguish the two tables.
The dcb_lock used for the APP table is reused for the rewrite table.
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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| #
ec32c0c4 |
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01-Nov-2022 |
Daniel Machon <daniel.machon@microchip.com> |
net: dcb: add new pcp selector to app object
Add new PCP selector for the 8021Qaz APP managed object.
As the PCP selector is not part of the 8021Qaz standard, a new non-std
extension attribute DCB_ATTR_DCB_APP has been introduced. Also two
helper functions to translate between selector and app attribute type
has been added. The new selector has been given a value of 255, to
minimize the risk of future overlap of std- and non-std attributes.
The new DCB_ATTR_DCB_APP is sent alongside the ieee std attribute in the
app table. This means that the dcb_app struct can now both contain std-
and non-std app attributes. Currently there is no overlap between the
selector values of the two attributes.
The purpose of adding the PCP selector, is to be able to offload
PCP-based queue classification to the 8021Q Priority Code Point table,
see 6.9.3 of IEEE Std 802.1Q-2018.
PCP and DEI is encoded in the protocol field as 8*dei+pcp, so that a
mapping of PCP 2 and DEI 1 to priority 3 is encoded as {255, 10, 3}.
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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| #
e549f6f9 |
|
22-Feb-2018 |
Huy Nguyen <huyn@mellanox.com> |
net/dcb: Add dcbnl buffer attribute
In this patch, we add dcbnl buffer attribute to allow user
change the NIC's buffer configuration such as priority
to buffer mapping and buffer size of individual buffer.
This attribute combined with pfc attribute allows advanced user to
fine tune the qos setting for specific priority queue. For example,
user can give dedicated buffer for one or more priorities or user
can give large buffer to certain priorities.
The dcb buffer configuration will be controlled by lldptool.
lldptool -T -i eth2 -V BUFFER prio 0,2,5,7,1,2,3,6
maps priorities 0,1,2,3,4,5,6,7 to receive buffer 0,2,5,7,1,2,3,6
lldptool -T -i eth2 -V BUFFER size 87296,87296,0,87296,0,0,0,0
sets receive buffer size for buffer 0,1,2,3,4,5,6,7 respectively
After discussion on mailing list with Jakub, Jiri, Ido and John, we agreed to
choose dcbnl over devlink interface since this feature is intended to set
port attributes which are governed by the netdev instance of that port, where
devlink API is more suitable for global ASIC configurations.
We present an use case scenario where dcbnl buffer attribute configured
by advance user helps reduce the latency of messages of different sizes.
Scenarios description:
On ConnectX-5, we run latency sensitive traffic with
small/medium message sizes ranging from 64B to 256KB and bandwidth sensitive
traffic with large messages sizes 512KB and 1MB. We group small, medium,
and large message sizes to their own pfc enables priorities as follow.
Priorities 1 & 2 (64B, 256B and 1KB)
Priorities 3 & 4 (4KB, 8KB, 16KB, 64KB, 128KB and 256KB)
Priorities 5 & 6 (512KB and 1MB)
By default, ConnectX-5 maps all pfc enabled priorities to a single
lossless fixed buffer size of 50% of total available buffer space. The
other 50% is assigned to lossy buffer. Using dcbnl buffer attribute,
we create three equal size lossless buffers. Each buffer has 25% of total
available buffer space. Thus, the lossy buffer size reduces to 25%. Priority
to lossless buffer mappings are set as follow.
Priorities 1 & 2 on lossless buffer #1
Priorities 3 & 4 on lossless buffer #2
Priorities 5 & 6 on lossless buffer #3
We observe improvements in latency for small and medium message sizes
as follows. Please note that the large message sizes bandwidth performance is
reduced but the total bandwidth remains the same.
256B message size (42 % latency reduction)
4K message size (21% latency reduction)
64K message size (16% latency reduction)
CC: Ido Schimmel <idosch@idosch.org>
CC: Jakub Kicinski <jakub.kicinski@netronome.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Or Gerlitz <gerlitz.or@gmail.com>
CC: Parav Pandit <parav@mellanox.com>
CC: Aron Silverton <aron.silverton@oracle.com>
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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| #
e2be04c7 |
|
01-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
License cleanup: add SPDX license identifier to uapi header files with a license
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.
Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.
GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.
Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)
SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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