From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
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.
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target.c | 20 +++++---------------
drivers/target/iscsi/iscsi_target_core.h | 13 ++++++-------
drivers/target/iscsi/iscsi_target_erl0.c | 2 +-
drivers/target/iscsi/iscsi_target_login.c | 1 -
drivers/target/iscsi/iscsi_target_stat.c | 22 ++++++++++++----------
drivers/target/iscsi/iscsi_target_util.c | 2 +-
6 files changed, 25 insertions(+), 35 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 241f913..19cc1a2 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -800,11 +800,9 @@ 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++;
+ atomic_long_inc(&conn->sess->cmd_pdus);
if (conn->sess->se_sess->se_node_acl)
atomic_long_inc(&conn->sess->se_sess->se_node_acl->num_cmds);
- spin_unlock_bh(&conn->sess->session_stats_lock);
hdr = (struct iscsi_scsi_req *) buf;
payload_length = ntoh24(hdr->dlength);
@@ -1251,12 +1249,10 @@ 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;
+ atomic_long_add(payload_length, &conn->sess->rx_data_octets);
if (conn->sess->se_sess->se_node_acl)
atomic_long_add(payload_length,
&conn->sess->se_sess->se_node_acl->write_bytes);
- spin_unlock_bh(&conn->sess->session_stats_lock);
if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
pr_err("DataSegmentLength: %u is greater than"
@@ -2626,12 +2622,10 @@ 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;
+ atomic_long_add(datain.length, &conn->sess->tx_data_octets);
if (conn->sess->se_sess->se_node_acl)
atomic_long_add(datain.length,
&conn->sess->se_sess->se_node_acl->read_bytes);
- spin_unlock_bh(&conn->sess->session_stats_lock);
/*
* Special case for successfully execution w/ both DATAIN
* and Sense Data.
@@ -3156,9 +3150,7 @@ 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;
@@ -4107,9 +4099,7 @@ restart:
* 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);
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index b03ee2f..f2094d2 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -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;
diff --git a/drivers/target/iscsi/iscsi_target_erl0.c b/drivers/target/iscsi/iscsi_target_erl0.c
index cbea7f1..0d1e6ee 100644
--- a/drivers/target/iscsi/iscsi_target_erl0.c
+++ b/drivers/target/iscsi/iscsi_target_erl0.c
@@ -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);
}
}
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 646632a..4eb93b2 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -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.
diff --git a/drivers/target/iscsi/iscsi_target_stat.c b/drivers/target/iscsi/iscsi_target_stat.c
index f788e8b..1033955 100644
--- a/drivers/target/iscsi/iscsi_target_stat.c
+++ b/drivers/target/iscsi/iscsi_target_stat.c
@@ -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);
@@ -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);
@@ -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);
@@ -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);
@@ -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);
@@ -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);
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index f2de28e..45b8fd1 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -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);
}
}
--
1.7.10.4
--
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