Re: [PATCH net-next v5 2/2] net/smc: handle -ENOMEM from smc_wr_alloc_link_mem gracefully

[Mahanta Jambigi <mjambigi@linux.ibm.com>]

On 29/09/25 7:20 am, Dust Li wrote:
>> diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
>> index 8d06c8bb14e9..5c18f08a4c8a 100644
>> --- a/net/smc/smc_core.h
>> +++ b/net/smc/smc_core.h
>> @@ -175,6 +175,8 @@ struct smc_link {
>> 	struct completion	llc_testlink_resp; /* wait for rx of testlink */
>> 	int			llc_testlink_time; /* testlink interval */
>> 	atomic_t		conn_cnt; /* connections on this link */
>> +	u16			max_send_wr;
>> +	u16			max_recv_wr;
> 
> Here, you've moved max_send_wr/max_recv_wr from the link group to individual links.
> This means we can now have different max_send_wr/max_recv_wr values on two
> different links within the same link group.
> Since in Alibaba we doesn't use multi-link configurations, we haven't tested

Does Alibaba always use a single RoCE device for SMC-R? In that case how
redundancy is achieved if that link goes down?

> this scenario. Have you tested the link-down handling process in a multi-link
> setup?
I did test this after you query & don't see any issues. As Halil
mentioned in worst case scenario one link might perform lesser than the
other, that too if the kcalloc() failed for that link in
smc_wr_alloc_link_mem() & succeeded in subsequent request with reduced
max_send_wr/max_recv_wr size(half).
> Otherwise, the patch looks good to me.
> 
> Best regards,
> Dust