From 4ae9715a5f79ecefb00839b92549fef226a39804 Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Mon, 4 May 2020 14:18:43 +0200 Subject: [PATCH] net/smc: assign link to a new connection For new connections, assign a link from the link group, using some simple load balancing. Signed-off-by: Karsten Graul Reviewed-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/smc_core.c | 65 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 46 insertions(+), 19 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 8f630b76c5a43..9c19b9aa3719a 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -121,16 +121,59 @@ static void smc_lgr_add_alert_token(struct smc_connection *conn) rb_insert_color(&conn->alert_node, &conn->lgr->conns_all); } +/* assign an SMC-R link to the connection */ +static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first) +{ + enum smc_link_state expected = first ? SMC_LNK_ACTIVATING : + SMC_LNK_ACTIVE; + int i, j; + + /* do link balancing */ + for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { + struct smc_link *lnk = &conn->lgr->lnk[i]; + + if (lnk->state != expected) + continue; + if (conn->lgr->role == SMC_CLNT) { + conn->lnk = lnk; /* temporary, SMC server assigns link*/ + break; + } + if (conn->lgr->conns_num % 2) { + for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) { + struct smc_link *lnk2; + + lnk2 = &conn->lgr->lnk[j]; + if (lnk2->state == expected) { + conn->lnk = lnk2; + break; + } + } + } + if (!conn->lnk) + conn->lnk = lnk; + break; + } + if (!conn->lnk) + return SMC_CLC_DECL_NOACTLINK; + return 0; +} + /* Register connection in link group by assigning an alert token * registered in a search tree. * Requires @conns_lock * Note that '0' is a reserved value and not assigned. */ -static int smc_lgr_register_conn(struct smc_connection *conn) +static int smc_lgr_register_conn(struct smc_connection *conn, bool first) { struct smc_sock *smc = container_of(conn, struct smc_sock, conn); static atomic_t nexttoken = ATOMIC_INIT(0); + int rc; + if (!conn->lgr->is_smcd) { + rc = smcr_lgr_conn_assign_link(conn, first); + if (rc) + return rc; + } /* find a new alert_token_local value not yet used by some connection * in this link group */ @@ -141,22 +184,6 @@ static int smc_lgr_register_conn(struct smc_connection *conn) conn->alert_token_local = 0; } smc_lgr_add_alert_token(conn); - - /* assign the new connection to a link */ - if (!conn->lgr->is_smcd) { - struct smc_link *lnk; - int i; - - /* tbd - link balancing */ - for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { - lnk = &conn->lgr->lnk[i]; - if (lnk->state == SMC_LNK_ACTIVATING || - lnk->state == SMC_LNK_ACTIVE) - conn->lnk = lnk; - } - if (!conn->lnk) - return SMC_CLC_DECL_NOACTLINK; - } conn->lgr->conns_num++; return 0; } @@ -1285,7 +1312,7 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini) /* link group found */ ini->cln_first_contact = SMC_REUSE_CONTACT; conn->lgr = lgr; - rc = smc_lgr_register_conn(conn); /* add conn to lgr */ + rc = smc_lgr_register_conn(conn, false); write_unlock_bh(&lgr->conns_lock); if (!rc && delayed_work_pending(&lgr->free_work)) cancel_delayed_work(&lgr->free_work); @@ -1313,7 +1340,7 @@ create: goto out; lgr = conn->lgr; write_lock_bh(&lgr->conns_lock); - rc = smc_lgr_register_conn(conn); /* add smc conn to lgr */ + rc = smc_lgr_register_conn(conn, true); write_unlock_bh(&lgr->conns_lock); if (rc) goto out; -- 2.39.5