On 23/06/2025 1:39, Zhu Yanjun wrote:
> 在 2025/6/22 10:22, Mark Bloch 写道:
>> This series optimizes ICM usage for unidirectional rules and
>> empty matchers and with the last patch we make hardware steering
>> the default FDB steering provider for NICs that don't support software
>> steering.
>
> In this patchset, ICM is not explained. I googled this ICM. And I got the following
>
> "
> ICM stands for Internal Context Memory, a specialized memory region used by Mellanox/NVIDIA network devices (e.g., ConnectX series NICs) to store hardware context and rule tables for offloaded operations like flow steering, filtering, and traffic redirection.
>
> ICM is crucial when using hardware steering (HWS), where the NIC itself performs packet matching and forwarding without involving the host CPU.
> "
Broadly speaking, yes. You can also check its consumption via devlink health reporter.
https://docs.kernel.org/networking/devlink/mlx5.html
check out icm_consumption on the above page.
Mark
> If I am missing something, please correct me.
>
> Zhu Yanjun
>
>>
>> Hardware steering (HWS) uses a type of rule table container (RTC) that
>> is unidirectional, so matchers consist of two RTCs to accommodate
>> bidirectional rules.
>>
>> This small series enables resizing the two RTCs independently by
>> tracking the number of rules separately. For extreme cases where all
>> rules are unidirectional, this results in saving close to half the
>> memory footprint.
>>
>> Results for inserting 1M unidirectional rules using a simple module:
>>
>> Pages Memory
>> Before this patch: 300k 1.5GiB
>> After this patch: 160k 900MiB
>>
>> The 'Pages' column measures the number of 4KiB pages the device requests
>> for itself (the ICM).
>>
>> The 'Memory' column is the difference between peak usage and baseline
>> usage (before starting the test) as reported by `free -h`.
>>
>> In addition, second to last patch of the series handles a case where all
>> the matcher's rules were deleted: the large RTCs of the matcher are no
>> longer required, and we can save some more ICM by shrinking the matcher
>> to its initial size.
>>
>> Finally the last patch makes hardware steering the default mode
>> when in swichdev for NICs that don't have software steering support.
>>
>> Changelog
>> =========
>> Changes from v1 [0]:
>> - Fixed author on patches 5 and 6.
>>
>> References
>> ==========
>> [0] v1: https://lore.kernel.org/all/20250619115522.68469-1-mbloch@nvidia.com/
>>
>> Moshe Shemesh (1):
>> net/mlx5: Add HWS as secondary steering mode
>>
>> Vlad Dogaru (5):
>> net/mlx5: HWS, remove unused create_dest_array parameter
>> net/mlx5: HWS, Refactor and export rule skip logic
>> net/mlx5: HWS, Create STEs directly from matcher
>> net/mlx5: HWS, Decouple matcher RX and TX sizes
>> net/mlx5: HWS, Track matcher sizes individually
>>
>> Yevgeny Kliteynik (2):
>> net/mlx5: HWS, remove incorrect comment
>> net/mlx5: HWS, Shrink empty matchers
>>
>> .../net/ethernet/mellanox/mlx5/core/fs_core.c | 2 +
>> .../mellanox/mlx5/core/steering/hws/action.c | 7 +-
>> .../mellanox/mlx5/core/steering/hws/bwc.c | 284 ++++++++++++++----
>> .../mellanox/mlx5/core/steering/hws/bwc.h | 14 +-
>> .../mellanox/mlx5/core/steering/hws/debug.c | 20 +-
>> .../mellanox/mlx5/core/steering/hws/fs_hws.c | 15 +-
>> .../mellanox/mlx5/core/steering/hws/matcher.c | 166 ++++++----
>> .../mellanox/mlx5/core/steering/hws/matcher.h | 3 +-
>> .../mellanox/mlx5/core/steering/hws/mlx5hws.h | 36 ++-
>> .../mellanox/mlx5/core/steering/hws/rule.c | 35 +--
>> .../mellanox/mlx5/core/steering/hws/rule.h | 3 +
>> 11 files changed, 403 insertions(+), 182 deletions(-)
>>
>>
>> base-commit: 091d019adce033118776ef93b50a268f715ae8f6
>
>