net/smc: do not wait under send_lock

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>
This commit is contained in:
Karsten Graul 2019-01-30 18:51:05 +01:00 committed by David S. Miller
parent 51c5aba3b6
commit 33f3fcc290

View File

@ -488,25 +488,23 @@ 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) {