From: Karsten Graul kgraul@linux.ibm.com
[ Upstream commit 33f3fcc290671590821ff3c0c9396db1ec9b7d4c ]
smc_cdc_get_free_slot() might wait for free transfer buffers when using SMC-R. This wait should not be done under the send_lock, which is a spin_lock. This fixes a cpu loop in parallel threads waiting for the send_lock.
Signed-off-by: Karsten Graul kgraul@linux.ibm.com Signed-off-by: Ursula Braun ubraun@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/smc/smc_tx.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 0ecbbdc337b82..62885a2781c9a 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -486,25 +486,23 @@ static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) struct smc_wr_buf *wr_buf; int rc;
- spin_lock_bh(&conn->send_lock); rc = smc_cdc_get_free_slot(conn, &wr_buf, &pend); if (rc < 0) { if (rc == -EBUSY) { struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
- if (smc->sk.sk_err == ECONNABORTED) { - rc = sock_error(&smc->sk); - goto out_unlock; - } + if (smc->sk.sk_err == ECONNABORTED) + return sock_error(&smc->sk); rc = 0; if (conn->alert_token_local) /* connection healthy */ mod_delayed_work(system_wq, &conn->tx_work, SMC_TX_WORK_DELAY); } - goto out_unlock; + return rc; }
+ spin_lock_bh(&conn->send_lock); if (!conn->local_tx_ctrl.prod_flags.urg_data_present) { rc = smc_tx_rdma_writes(conn); if (rc) {