Re: [PATCH net] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error

D. Wythe
2022-02-25T16:45:13Z

在 2022/2/25 下午4:11, D. Wythe 写道:
> From: "D. Wythe" <alibuda@linux.alibaba.com>
>
> Remove connections from link group is not synchronous with handling
> SMC_LLC_DELETE_RKEY, which means that even the number of connections is
> less that SMC_RMBS_PER_LGR_MAX, it does not mean that the connection can
> register rtoken successfully later, in other words, the rtoken entry may
> have not been released. This will cause an unexpected
> SMC_CLC_DECL_ERR_REGRMB to be reported, and then ths smc connection have
> to fallback to TCP.
>
> Therefore, we need to judge according to the number of idle rtoken
> entry.
>
> Fixes: cd6851f30386 ("smc: remote memory buffers (RMBs)")
> Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
> ---
> net/smc/smc_core.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
> index 29525d0..24ef0af 100644
> --- a/net/smc/smc_core.c
> +++ b/net/smc/smc_core.c
> @@ -1864,7 +1864,8 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
> (ini->smcd_version == SMC_V2 ||
> lgr->vlan_id == ini->vlan_id) &&
> (role == SMC_CLNT || ini->is_smcd ||
> - lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
> + lgr->conns_num < SMC_RMBS_PER_LGR_MAX -
> + bitmap_weight(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX))) {
> /* link group found */
> ini->first_contact_local = 0;
> conn->lgr = lgr;

I did a horrible math here, i'll send another fix later.

Best wishes.