[PATCH net-next 06/10] net/smc: longer delay for client link group removal
From: Ursula Braun <hidden>
Date: 2017-09-20 11:58:32
Also in:
linux-rdma, linux-s390
Subsystem:
networking [general], shared memory communications (smc) sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, D. Wythe, Dust Li, Sidraya Jayagond, Mahanta Jambigi, Linus Torvalds
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 <redacted> --- 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