> -----Original Message-----
> From: Dipayaan Roy <[email protected]>
> Sent: Wednesday, July 23, 2025 3:07 PM
> To: [email protected]; [email protected]; KY Srinivasan <[email protected]>;
> Haiyang Zhang <[email protected]>; [email protected]; Dexuan Cui
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; Long Li <[email protected]>;
> Konstantin Taranov <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; Shiraz Saleem
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; Dipayaan Roy <[email protected]>
> Subject: [PATCH v2] net: mana: Use page pool fragments for RX buffers
> instead of full pages to improve memory efficiency.
>
> This patch enhances RX buffer handling in the mana driver by allocating
> pages from a page pool and slicing them into MTU-sized fragments, rather
> than dedicating a full page per packet. This approach is especially
> beneficial on systems with large page sizes like 64KB.
>
> Key improvements:
>
> - Proper integration of page pool for RX buffer allocations.
> - MTU-sized buffer slicing to improve memory utilization.
> - Reduce overall per Rx queue memory footprint.
> - Automatic fallback to full-page buffers when:
> * Jumbo frames are enabled (MTU > PAGE_SIZE / 2).
> * The XDP path is active, to avoid complexities with fragment reuse.
> - Removal of redundant pre-allocated RX buffers used in scenarios like MTU
> changes, ensuring consistency in RX buffer allocation.
>
> Testing on VMs with 64KB pages shows around 200% throughput improvement.
> Memory efficiency is significantly improved due to reduced wastage in page
> allocations. Example: We are now able to fit 35 rx buffers in a single
> 64kb
> page for MTU size of 1500, instead of 1 rx buffer per page previously.
>
> Tested:
>
> - iperf3, iperf2, and nttcp benchmarks.
> - Jumbo frames with MTU 9000.
> - Native XDP programs (XDP_PASS, XDP_DROP, XDP_TX, XDP_REDIRECT) for
> testing the XDP path in driver.
> - Page leak detection (kmemleak).
> - Driver load/unload, reboot, and stress scenarios.
>
> Signed-off-by: Dipayaan Roy <[email protected]>
>
> Reviewed-by: Jacob Keller <[email protected]>
> Reviewed-by: Saurabh Sengar <[email protected]>
Reviewed-by: Haiyang Zhang <[email protected]>
