On Fri, Feb 27, 2026 at 02:15:12AM -0800, Dipayaan Roy wrote:

On certain systems configured with 4K PAGE_SIZE, utilizing page_pool
fragments for RX buffers results in a significant throughput regression.
Profiling reveals that this regression correlates with high overhead in the
fragment allocation and reference counting paths on these specific
platforms, rendering the multi-buffer-per-page strategy counterproductive.

To mitigate this, bypass the page_pool fragment path and force a single RX
packet per page allocation when all the following conditions are met:
  1. The system is configured with a 4K PAGE_SIZE.
  2. A processor-specific quirk is detected via SMBIOS Type 4 data.

This approach restores expected line-rate performance by ensuring
predictable RX refill behavior on affected hardware.

There is no behavioral change for systems using larger page sizes
(16K/64K), or platforms where this processor-specific quirk do not
apply.

Signed-off-by: Dipayaan Roy <redacted>

Reviewed-by: Simon Horman <horms@kernel.org>