diff options
| author | Nicholas Bellinger | 2013-10-03 13:56:14 -0700 |
|---|---|---|
| committer | Nicholas Bellinger | 2013-10-03 14:22:45 -0700 |
| commit | f56cbbb4b5871e5bc2838ddeeba5b29debc2a734 (patch) | |
| tree | 6ea3d9dd0b0bb7c652337ddf7d86f94268917a54 | |
| parent | e255a28598e8e63070322fc89bd34189dd660a89 (diff) | |
iscsi-target: Perform release of acknowledged tags from RX context
This patch converts iscsit_ack_from_expstatsn() to populate a local
ack_list of commands, and call iscsit_free_cmd() directly from RX
thread context, instead of using iscsit_add_cmd_to_immediate_queue()
to queue the acknowledged commands to be released from TX thread
context.
It is helpful to release the acknowledge commands as quickly as
possible, along with the associated percpu_ida tags, in order to
prevent percpu_ida_alloc() from having to steal tags from other
CPUs while waiting for iscsit_free_cmd() to happen from TX thread
context.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
| -rw-r--r-- | drivers/target/iscsi/iscsi_target.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 35b61f7d6c63..38e44b9abf0f 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -753,7 +753,8 @@ static void iscsit_unmap_iovec(struct iscsi_cmd *cmd) static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn) { - struct iscsi_cmd *cmd; + LIST_HEAD(ack_list); + struct iscsi_cmd *cmd, *cmd_p; conn->exp_statsn = exp_statsn; @@ -761,19 +762,23 @@ static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn) return; spin_lock_bh(&conn->cmd_lock); - list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) { + list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) { spin_lock(&cmd->istate_lock); if ((cmd->i_state == ISTATE_SENT_STATUS) && iscsi_sna_lt(cmd->stat_sn, exp_statsn)) { cmd->i_state = ISTATE_REMOVE; spin_unlock(&cmd->istate_lock); - iscsit_add_cmd_to_immediate_queue(cmd, conn, - cmd->i_state); + list_move_tail(&cmd->i_conn_node, &ack_list); continue; } spin_unlock(&cmd->istate_lock); } spin_unlock_bh(&conn->cmd_lock); + + list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) { + list_del(&cmd->i_conn_node); + iscsit_free_cmd(cmd, false); + } } static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd) |