When using a MPC8xx as a router, 'perf' shows a significant time spent in fs_enet_interrupt() and fs_enet_start_xmit(). 'perf annotate' shows that the time spent in fs_enet_start_xmit is indeed spent between spin_unlock_irqrestore() and the following instruction, hence in interrupt handling. This is due to the TX complete interrupt that fires after each transmitted packet. This patchset first remove all non NAPI handling as NAPI has become the only mode for RX, then adds NAPI for handling TX complete. This improves NAT TCP throughput by 21% on MPC885 with FEC.
Tested on MPC885 with FEC. [PATCH 1/2] net: fs_enet: Remove non NAPI RX [PATCH 2/2] net: fs_enet: Add NAPI TX Signed-off-by: Christophe Leroy <[email protected]> --- .../net/ethernet/freescale/fs_enet/fs_enet-main.c | 211 ++++++--------------- .../net/ethernet/freescale/fs_enet/fs_enet.h | 9 +- .../net/ethernet/freescale/fs_enet/mac-fcc.c | 29 +++ .../net/ethernet/freescale/fs_enet/mac-fec.c | 29 +++ .../net/ethernet/freescale/fs_enet/mac-scc.c | 29 +++ linux/include/linux/fs_enet_pd.h | 1 - 6 files changed, 147 insertions(+), 161 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
