[PATCH net-next v6 0/2] net: mana: add ethtool private flag for full-page RX buffers

Dipayaan Roy
2026-04-07T20:02:52Z

On some ARM64 platforms with 4K PAGE_SIZE, utilizing page_pool
fragments for allocation in the RX refill path (~2kB buffer per fragment)
causes 15-20% throughput regression under high connection counts
(>16 TCP streams at 180+ Gbps). Using full-page buffers on these
platforms shows no regression and restores line-rate performance.

This behavior is observed on a single platform; other platforms
perform better with page_pool fragments, indicating this is not a
page_pool issue but platform-specific.

This series adds an ethtool private flag "full-page-rx" to let the
user opt in to one RX buffer per page:

ethtool --set-priv-flags eth0 full-page-rx on

There is no behavioral change by default. The flag can be persisted
via udev rule for affected platforms.

Changes in v6:
- Added missed maintainers.
Changes in v5:
- Split prep refactor into separate patch (patch 1/2)
Changes in v4:
- Dropping the smbios string parsing and add ethtool priv flag
to reconfigure the queues with full page rx buffers.
Changes in v3:
- changed u8* to char*
Changes in v2:
- separate reading string index and the string, remove inline.

Dipayaan Roy (2):
net: mana: refactor mana_get_strings() and mana_get_sset_count() to
use switch
net: mana: force full-page RX buffers via ethtool private flag

drivers/net/ethernet/microsoft/mana/mana_en.c | 22 ++-
.../ethernet/microsoft/mana/mana_ethtool.c | 164 ++++++++++++++----
include/net/mana/mana.h | 8 +
3 files changed, 163 insertions(+), 31 deletions(-)

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2.43.0