> -----Original Message----- > From: Dipayaan Roy <dipayanroy@xxxxxxxxxxxxxxxxxxx> > Sent: Wednesday, July 23, 2025 3:07 PM > To: horms@xxxxxxxxxx; kuba@xxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>; > Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; wei.liu@xxxxxxxxxx; Dexuan Cui > <decui@xxxxxxxxxxxxx>; andrew+netdev@xxxxxxx; davem@xxxxxxxxxxxxx; > edumazet@xxxxxxxxxx; pabeni@xxxxxxxxxx; Long Li <longli@xxxxxxxxxxxxx>; > Konstantin Taranov <kotaranov@xxxxxxxxxxxxx>; ast@xxxxxxxxxx; > daniel@xxxxxxxxxxxxx; hawk@xxxxxxxxxx; john.fastabend@xxxxxxxxx; > sdf@xxxxxxxxxxx; lorenzo@xxxxxxxxxx; michal.kubiak@xxxxxxxxx; > ernis@xxxxxxxxxxxxxxxxxxx; shradhagupta@xxxxxxxxxxxxxxxxxxx; Shiraz Saleem > <shirazsaleem@xxxxxxxxxxxxx>; rosenp@xxxxxxxxx; netdev@xxxxxxxxxxxxxxx; > linux-hyperv@xxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; > bpf@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > ssengar@xxxxxxxxxxxxxxxxxxx; Dipayaan Roy <dipayanroy@xxxxxxxxxxxxx> > 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 <dipayanroy@xxxxxxxxxxxxxxxxxxx> > > Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx> > Reviewed-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
