[ovs-dev] [ovs-dev, v2] netdev-dpdk: dfc_process optimization by

[Yanqin Wei (Arm Technology China)]

Thanks for the comments. It will be fixed in the following patch v3.

-----Original Message-----
From: Ilya Maximets <i.maximets at samsung.com> 
Sent: Tuesday, March 12, 2019 9:31 PM
To: Yanqin Wei (Arm Technology China) <Yanqin.Wei at arm.com>; dev at openvswitch.org
Cc: nd <nd at arm.com>; Gavin Hu (Arm Technology China) <Gavin.Hu at arm.com>
Subject: Re: [ovs-dev,v2] netdev-dpdk: dfc_process optimization by

Hi.

Thanks for working on this.
Not a full review, just a few notes about formatting.

1. Looks like your subject line was accidentally cropped.
2. This change is local to generic parts of 'dpif-netdev', so, the "area" in
   a subject line should be 'dpif-netdev'. There is nothing DPDK specific here.

On 11.03.2019 14:44, Yanqin Wei wrote:
> It is observed that the throughput of multi-flow is worse than 
> single-flow in the EMC NIC to NIC cases. It is because CPU cache-miss 
> increasing in EMC lookup. Each flow need load at least one EMC entry 
> to CPU cache(several cache lines) and compare it with packet miniflow.
> This patch improve it by prefetching EMC entry in advance. Hash value 
> can be obtained from dpdk rss hash, so this step can be advanced ahead 
> of
> miniflow_extract() and prefetch EMC entry there. The prefetching size 
> is defined as ROUND_UP(128,CACHE_LINE_SIZE), which can cover majority 
> traffic including TCP/UDP protocol and need 2 cache lines in most modern CPU.
> Performance test was run in some arm platform. 1000/10000 flows 
> NIC2NIC test achieved around 10% throughput improvement in 
> thunderX2(aarch64 platform).
> 
> Signed-off-by: Yanqin Wei <Yanqin.Wei at arm.com>
> Reviewed-by: Gavin Hu <Gavin.Hu at arm.com>
> ---
>  lib/dpif-netdev.c | 80 
> ++++++++++++++++++++++++++++++++++++-------------------
>  1 file changed, 52 insertions(+), 28 deletions(-)  mode change 100644 
> => 100755 lib/dpif-netdev.c
> 
> diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c old mode 100644 new 
> mode 100755

3. Please, don't change the file mode.

Best regards, Ilya Maximets.