Re: [PATCHv2 1/1] net: rds: add service level support in rds-info

[santosh.shilimkar@oracle.com]

On 8/23/19 6:04 PM, Zhu Yanjun wrote:
>  From IB specific 7.6.5 SERVICE LEVEL, Service Level (SL)
> is used to identify different flows within an IBA subnet.
> It is carried in the local route header of the packet.
> 
> Before this commit, run "rds-info -I". The outputs are as
> below:
> "
> RDS IB Connections:
>   LocalAddr  RemoteAddr Tos SL  LocalDev               RemoteDev
> 192.2.95.3  192.2.95.1  2   0  fe80::21:28:1a:39  fe80::21:28:10:b9
> 192.2.95.3  192.2.95.1  1   0  fe80::21:28:1a:39  fe80::21:28:10:b9
> 192.2.95.3  192.2.95.1  0   0  fe80::21:28:1a:39  fe80::21:28:10:b9
> "
> After this commit, the output is as below:
> "
> RDS IB Connections:
>   LocalAddr  RemoteAddr Tos SL  LocalDev               RemoteDev
> 192.2.95.3  192.2.95.1  2   2  fe80::21:28:1a:39  fe80::21:28:10:b9
> 192.2.95.3  192.2.95.1  1   1  fe80::21:28:1a:39  fe80::21:28:10:b9
> 192.2.95.3  192.2.95.1  0   0  fe80::21:28:1a:39  fe80::21:28:10:b9
> "
> 
> The commit fe3475af3bdf ("net: rds: add per rds connection cache
> statistics") adds cache_allocs in struct rds_info_rdma_connection
> as below:
> struct rds_info_rdma_connection {
> ...
>          __u32           rdma_mr_max;
>          __u32           rdma_mr_size;
>          __u8            tos;
>          __u32           cache_allocs;
>   };
> The peer struct in rds-tools of struct rds_info_rdma_connection is as
> below:
> struct rds_info_rdma_connection {
> ...
>          uint32_t        rdma_mr_max;
>          uint32_t        rdma_mr_size;
>          uint8_t         tos;
>          uint8_t         sl;
>          uint32_t        cache_allocs;
> };
> The difference between userspace and kernel is the member variable sl.
> In the kernel struct, the member variable sl is missing. This will
> introduce risks. So it is necessary to use this commit to avoid this risk.
> 
> Fixes: fe3475af3bdf ("net: rds: add per rds connection cache statistics")
> CC: Joe Jin <joe.jin@oracle.com>
> CC: JUNXIAO_BI <junxiao.bi@oracle.com>
> Suggested-by: Gerd Rausch <gerd.rausch@oracle.com>
> Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
> ---
> V1->V2: fix typos in commit logs.
> ---
I did ask you when ypu posted the patch about whether you did
backward compatibility tests for which you said, you did all the
tests and said "So do not worry about backward compatibility.  This
commit will work well with older rds-tools2.0.5 and 2.0.6."

https://www.spinics.net/lists/netdev/msg574691.html

I was worried about exactly such issue as described in commit.

Anyways thanks for the fixup patch. Should be applied to stable
as well.

Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

Regards,
Santosh