Re: [PATCH 0/2] net: fs_enet: Remove non NAPI RX and add NAPI for TX
From: Christophe Leroy christophe.le...@c-s.fr Date: Tue, 7 Oct 2014 15:04:53 +0200 (CEST) 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 christophe.le...@c-s.fr Series applied, thanks. Any particular reason you didn't just put the TX reclaim calls into the existing NAPI handler? That's what other drivers do, because TX reclaim can make SKBs available for RX packet receive on the local cpu. So generally you have one NAPI context that first does any pending TX reclaim, then polls the RX ring for new packets. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 0/2] net: fs_enet: Remove non NAPI RX and add NAPI for TX
Le 08/10/2014 22:03, David Miller a écrit : From: Christophe Leroy christophe.le...@c-s.fr Date: Tue, 7 Oct 2014 15:04:53 +0200 (CEST) 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 christophe.le...@c-s.fr Series applied, thanks. Any particular reason you didn't just put the TX reclaim calls into the existing NAPI handler? Not really. I used the gianfar.c driver as a model. That's what other drivers do, because TX reclaim can make SKBs available for RX packet receive on the local cpu. So generally you have one NAPI context that first does any pending TX reclaim, then polls the RX ring for new packets. Is that a better approach ? ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH 0/2] net: fs_enet: Remove non NAPI RX and add NAPI for TX
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 christophe.le...@c-s.fr --- .../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(-) ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
