Skip to content

Commit

Permalink
iscsi-target: Convert iscsi_session statistics to atomic_long_t
Browse files Browse the repository at this point in the history 
This patch converts a handful of iscsi_session statistics to type
atomic_long_t, instead of using iscsi_session->session_stats_lock
when incrementing these values.

More importantly, go ahead and drop the spinlock usage within
iscsit_setup_scsi_cmd(), iscsit_check_dataout_hdr(),
iscsit_send_datain(), and iscsit_build_rsp_pdu() fast-path code.

(Squash in Roland's  target: Remove write-only stats fields and lock
from struct se_node_acl)

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
  • Loading branch information
Nicholas Bellinger committed Nov 20, 2013
1 parent ee48068 commit 04f3b31
Show file tree
Hide file tree
Showing 6 changed files with 25 additions and 50 deletions.
35 changes: 5 additions & 30 deletions drivers/target/iscsi/iscsi_target.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -800,14 +800,7 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
int iscsi_task_attr;
int sam_task_attr;

spin_lock_bh(&conn->sess->session_stats_lock);
conn->sess->cmd_pdus++;
if (conn->sess->se_sess->se_node_acl) {
spin_lock(&conn->sess->se_sess->se_node_acl->stats_lock);
conn->sess->se_sess->se_node_acl->num_cmds++;
spin_unlock(&conn->sess->se_sess->se_node_acl->stats_lock);
}
spin_unlock_bh(&conn->sess->session_stats_lock);
atomic_long_inc(&conn->sess->cmd_pdus);

hdr = (struct iscsi_scsi_req *) buf;
payload_length = ntoh24(hdr->dlength);
Expand Down Expand Up @@ -1254,14 +1247,7 @@ iscsit_check_dataout_hdr(struct iscsi_conn *conn, unsigned char *buf,
}

/* iSCSI write */
spin_lock_bh(&conn->sess->session_stats_lock);
conn->sess->rx_data_octets += payload_length;
if (conn->sess->se_sess->se_node_acl) {
spin_lock(&conn->sess->se_sess->se_node_acl->stats_lock);
conn->sess->se_sess->se_node_acl->write_bytes += payload_length;
spin_unlock(&conn->sess->se_sess->se_node_acl->stats_lock);
}
spin_unlock_bh(&conn->sess->session_stats_lock);
atomic_long_add(payload_length, &conn->sess->rx_data_octets);

if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
pr_err("DataSegmentLength: %u is greater than"
Expand Down Expand Up @@ -2631,14 +2617,7 @@ static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
return -1;
}

spin_lock_bh(&conn->sess->session_stats_lock);
conn->sess->tx_data_octets += datain.length;
if (conn->sess->se_sess->se_node_acl) {
spin_lock(&conn->sess->se_sess->se_node_acl->stats_lock);
conn->sess->se_sess->se_node_acl->read_bytes += datain.length;
spin_unlock(&conn->sess->se_sess->se_node_acl->stats_lock);
}
spin_unlock_bh(&conn->sess->session_stats_lock);
atomic_long_add(datain.length, &conn->sess->tx_data_octets);
/*
* Special case for successfully execution w/ both DATAIN
* and Sense Data.
Expand Down Expand Up @@ -3163,9 +3142,7 @@ void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
if (inc_stat_sn)
cmd->stat_sn = conn->stat_sn++;

spin_lock_bh(&conn->sess->session_stats_lock);
conn->sess->rsp_pdus++;
spin_unlock_bh(&conn->sess->session_stats_lock);
atomic_long_inc(&conn->sess->rsp_pdus);

memset(hdr, 0, ISCSI_HDR_LEN);
hdr->opcode = ISCSI_OP_SCSI_CMD_RSP;
Expand Down Expand Up @@ -4114,9 +4091,7 @@ int iscsi_target_rx_thread(void *arg)
* hit default in the switch below.
*/
memset(buffer, 0xff, ISCSI_HDR_LEN);
spin_lock_bh(&conn->sess->session_stats_lock);
conn->sess->conn_digest_errors++;
spin_unlock_bh(&conn->sess->session_stats_lock);
atomic_long_inc(&conn->sess->conn_digest_errors);
} else {
pr_debug("Got HeaderDigest CRC32C"
" 0x%08x\n", checksum);
Expand Down
13 changes: 6 additions & 7 deletions drivers/target/iscsi/iscsi_target_core.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -651,14 +651,13 @@ struct iscsi_session {
/* Used for session reference counting */
int session_usage_count;
int session_waiting_on_uc;
u32 cmd_pdus;
u32 rsp_pdus;
u64 tx_data_octets;
u64 rx_data_octets;
u32 conn_digest_errors;
u32 conn_timeout_errors;
atomic_long_t cmd_pdus;
atomic_long_t rsp_pdus;
atomic_long_t tx_data_octets;
atomic_long_t rx_data_octets;
atomic_long_t conn_digest_errors;
atomic_long_t conn_timeout_errors;
u64 creation_time;
spinlock_t session_stats_lock;
/* Number of active connections */
atomic_t nconn;
atomic_t session_continuation;
Expand Down
2 changes: 1 addition & 1 deletion drivers/target/iscsi/iscsi_target_erl0.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -785,7 +785,7 @@ static void iscsit_handle_time2retain_timeout(unsigned long data)
tiqn->sess_err_stats.last_sess_failure_type =
ISCSI_SESS_ERR_CXN_TIMEOUT;
tiqn->sess_err_stats.cxn_timeout_errors++;
sess->conn_timeout_errors++;
atomic_long_inc(&sess->conn_timeout_errors);
spin_unlock(&tiqn->sess_err_stats.lock);
}
}
Expand Down
1 change: 0 additions & 1 deletion drivers/target/iscsi/iscsi_target_login.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -305,7 +305,6 @@ static int iscsi_login_zero_tsih_s1(
}

sess->creation_time = get_jiffies_64();
spin_lock_init(&sess->session_stats_lock);
/*
* The FFP CmdSN window values will be allocated from the TPG's
* Initiator Node's ACL once the login has been successfully completed.
Expand Down
22 changes: 12 additions & 10 deletions drivers/target/iscsi/iscsi_target_stat.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -792,7 +792,8 @@ static ssize_t iscsi_stat_sess_show_attr_cmd_pdus(
if (se_sess) {
sess = se_sess->fabric_sess_ptr;
if (sess)
ret = snprintf(page, PAGE_SIZE, "%u\n", sess->cmd_pdus);
ret = snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&sess->cmd_pdus));
}
spin_unlock_bh(&se_nacl->nacl_sess_lock);

Expand All @@ -815,7 +816,8 @@ static ssize_t iscsi_stat_sess_show_attr_rsp_pdus(
if (se_sess) {
sess = se_sess->fabric_sess_ptr;
if (sess)
ret = snprintf(page, PAGE_SIZE, "%u\n", sess->rsp_pdus);
ret = snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&sess->rsp_pdus));
}
spin_unlock_bh(&se_nacl->nacl_sess_lock);

Expand All @@ -838,8 +840,8 @@ static ssize_t iscsi_stat_sess_show_attr_txdata_octs(
if (se_sess) {
sess = se_sess->fabric_sess_ptr;
if (sess)
ret = snprintf(page, PAGE_SIZE, "%llu\n",
(unsigned long long)sess->tx_data_octets);
ret = snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&sess->tx_data_octets));
}
spin_unlock_bh(&se_nacl->nacl_sess_lock);

Expand All @@ -862,8 +864,8 @@ static ssize_t iscsi_stat_sess_show_attr_rxdata_octs(
if (se_sess) {
sess = se_sess->fabric_sess_ptr;
if (sess)
ret = snprintf(page, PAGE_SIZE, "%llu\n",
(unsigned long long)sess->rx_data_octets);
ret = snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&sess->rx_data_octets));
}
spin_unlock_bh(&se_nacl->nacl_sess_lock);

Expand All @@ -886,8 +888,8 @@ static ssize_t iscsi_stat_sess_show_attr_conn_digest_errors(
if (se_sess) {
sess = se_sess->fabric_sess_ptr;
if (sess)
ret = snprintf(page, PAGE_SIZE, "%u\n",
sess->conn_digest_errors);
ret = snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&sess->conn_digest_errors));
}
spin_unlock_bh(&se_nacl->nacl_sess_lock);

Expand All @@ -910,8 +912,8 @@ static ssize_t iscsi_stat_sess_show_attr_conn_timeout_errors(
if (se_sess) {
sess = se_sess->fabric_sess_ptr;
if (sess)
ret = snprintf(page, PAGE_SIZE, "%u\n",
sess->conn_timeout_errors);
ret = snprintf(page, PAGE_SIZE, "%lu\n",
atomic_long_read(&sess->conn_timeout_errors));
}
spin_unlock_bh(&se_nacl->nacl_sess_lock);

Expand Down
2 changes: 1 addition & 1 deletion drivers/target/iscsi/iscsi_target_util.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -980,7 +980,7 @@ static void iscsit_handle_nopin_response_timeout(unsigned long data)
tiqn->sess_err_stats.last_sess_failure_type =
ISCSI_SESS_ERR_CXN_TIMEOUT;
tiqn->sess_err_stats.cxn_timeout_errors++;
conn->sess->conn_timeout_errors++;
atomic_long_inc(&conn->sess->conn_timeout_errors);
spin_unlock_bh(&tiqn->sess_err_stats.lock);
}
}
Expand Down

0 comments on commit 04f3b31

Please sign in to comment.