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authorNicholas Bellinger <nab@linux-iscsi.org>2013-10-03 13:56:14 -0700
committerNicholas Bellinger <nab@linux-iscsi.org>2013-10-03 14:22:45 -0700
commitf56cbbb4b5871e5bc2838ddeeba5b29debc2a734 (patch)
tree6ea3d9dd0b0bb7c652337ddf7d86f94268917a54
parente255a28598e8e63070322fc89bd34189dd660a89 (diff)
downloadlinux-stericsson-f56cbbb4b5871e5bc2838ddeeba5b29debc2a734.tar.gz
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.c13
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)