From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ursula Braun Subject: [PATCH net-next 06/10] net/smc: longer delay for client link group removal Date: Wed, 20 Sep 2017 13:58:09 +0200 Message-ID: <20170920115813.63745-7-ubraun@linux.vnet.ibm.com> References: <20170920115813.63745-1-ubraun@linux.vnet.ibm.com> Return-path: In-Reply-To: <20170920115813.63745-1-ubraun@linux.vnet.ibm.com> Sender: netdev-owner@vger.kernel.org To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, jwi@linux.vnet.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, raspl@linux.vnet.ibm.com, ubraun@linux.vnet.ibm.com List-Id: linux-rdma@vger.kernel.org Client link group creation always follows the server linkgroup creation. If peer creates a new server link group, client has to create a new client link group. If peer reuses a server link group for a new connection, client has to reuse its client link group as well. This patch introduces a longer delay for client link group removal to make sure this link group still exists, once the peer decides to reuse a server link group. This avoids out-of-sync conditions for link groups. If already scheduled, modify the delay. Signed-off-by: Ursula Braun --- net/smc/smc_core.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 1a16d51e2330..20b66e79c5d6 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -25,8 +25,9 @@ #include "smc_cdc.h" #include "smc_close.h" -#define SMC_LGR_NUM_INCR 256 -#define SMC_LGR_FREE_DELAY (600 * HZ) +#define SMC_LGR_NUM_INCR 256 +#define SMC_LGR_FREE_DELAY_SERV (600 * HZ) +#define SMC_LGR_FREE_DELAY_CLNT (SMC_LGR_FREE_DELAY_SERV + 10) static u32 smc_lgr_num; /* unique link group number */ @@ -107,8 +108,15 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn) __smc_lgr_unregister_conn(conn); } write_unlock_bh(&lgr->conns_lock); - if (reduced && !lgr->conns_num) - schedule_delayed_work(&lgr->free_work, SMC_LGR_FREE_DELAY); + if (!reduced || lgr->conns_num) + return; + /* client link group creation always follows the server link group + * creation. For client use a somewhat higher removal delay time, + * otherwise there is a risk of out-of-sync link groups. + */ + mod_delayed_work(system_wq, &lgr->free_work, + lgr->role == SMC_CLNT ? SMC_LGR_FREE_DELAY_CLNT : + SMC_LGR_FREE_DELAY_SERV); } static void smc_lgr_free_work(struct work_struct *work) -- 2.13.5