[ovs-dev] [PATCH ovs-dev v3 4/4] Revert "dpif-netdev: includes microsecond delta in meter bucket calculation".

[Ilya Maximets]

On 5/23/20 12:33 PM, xiangxia.m.yue at gmail.com wrote:
> From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
> 
> This reverts commit 5c41c31ebd64fda821fb733a5784a7a440a794f8.
> 
> Use the pktgen-dpdk to test the commit 5c41c31ebd64
> ("dpif-netdev: includes microsecond delta in meter bucket calculation"), it
> does't work as expected. And it broken the meter function (e.g. set rate
> 200Mbps, the rate watched was 400Mbps). To reproduce it:
> 
> $ ovs-vsctl add-br br-int -- set bridge br-int datapath_type=netdev
> $ ovs-ofctl -O OpenFlow13 add-meter br-int \
>         "meter=100 kbps burst stats bands=type=drop rate=200000 burst_size=200000"
> $ ovs-ofctl -O OpenFlow13 add-flow br-int \
>         "in_port=dpdk0 action=meter:100,output:dpdk1"
> $ pktgen -l 1,3,5,7,9,11,13,15,17,19 -n 8 --socket-mem 4096 --file-prefix pg1 \
>         -w 0000:82:00.0 -w 0000:82:00.1 -- -T -P -m "[3/5/7/9/11/13/15].[0-1]" -f meter-test.pkt
> 
> meter-test.pkt:
> | set 0 count 0
> | set 0 size 1500
> | set 0 rate 100
> | set 0 burst 64
> | set 0 sport 1234
> | set 0 dport 5678
> | set 0 prime 1
> | set 0 type ipv4
> | set 0 proto udp
> | set 0 dst ip 1.1.1.2
> | set 0 src ip 1.1.1.1/24
> | set 0 dst mac ec:0d:9a:ab:54:0a
> | set 0 src mac ec:0d:9a:bf:df:bb
> | set 0 vlanid 0
> | start 0
> 
> Note that 42697ca7757b ("dpif-netdev: fix meter at high packet rate.") has fixed it as 5c41c31ebd64.
> 
> Cc: Ilya Maximets <i.maximets at ovn.org>
> Cc: William Tu <u9012063 at gmail.com>
> Cc: Jarno Rajahalme <jarno at ovn.org>
> Cc: Ben Pfaff <blp at ovn.org>
> Cc: Andy Zhou <azhou at ovn.org>
> Cc: Jiang Lidong <jianglidong3 at jd.com>
> Cc: Pravin Shelar <pshelar at ovn.org>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
> ---

Thanks!

Since this is a bug fix, I applied this one patch to master and branch-2.14.
Will get back to review other patches later.

Bets regards, Ilya Maximets.

>  lib/dpif-netdev.c | 5 -----
>  1 file changed, 5 deletions(-)
> 
> diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
> index 776a16dab6e8..46eb1e3d97c9 100644
> --- a/lib/dpif-netdev.c
> +++ b/lib/dpif-netdev.c
> @@ -5904,7 +5904,6 @@ dp_netdev_run_meter(struct dp_netdev *dp, struct dp_packet_batch *packets_,
>      struct dp_packet *packet;
>      long long int long_delta_t; /* msec */
>      uint32_t delta_t; /* msec */
> -    uint32_t delta_in_us; /* usec */
>      const size_t cnt = dp_packet_batch_size(packets_);
>      uint32_t bytes, volume;
>      int exceeded_band[NETDEV_MAX_BURST];
> @@ -5935,9 +5934,6 @@ dp_netdev_run_meter(struct dp_netdev *dp, struct dp_packet_batch *packets_,
>             Assuming that all racing threads received packets at the same time
>             to avoid overflow. */
>          long_delta_t = 0;
> -        delta_in_us  = 0;
> -    } else {
> -        delta_in_us  = (now - meter->used) % 1000;
>      }
>  
>      /* Make sure delta_t will not be too large, so that bucket will not
> @@ -5973,7 +5969,6 @@ dp_netdev_run_meter(struct dp_netdev *dp, struct dp_packet_batch *packets_,
>  
>          /* Update band's bucket. */
>          band->bucket += (uint64_t)delta_t * band->up.rate;
> -        band->bucket += delta_in_us * band->up.rate / 1000;
>          if (band->bucket > band->up.burst_size) {
>              band->bucket = band->up.burst_size;
>          }
>