Or Gerlitz wrote:
> I can't go over this max when applying my patch of lockless flow for
> queuecommand / passthrough
this is the patch I was using till today when I started to suspect it doesn't
yield any
or very little of IOPS over the rest of the patches.
---
drivers/infiniband/ulp/iser/iser_memory.c | 2 ++
drivers/scsi/libiscsi.c | 26 ++++++++++++++++++--------
2 files changed, 20 insertions(+), 8 deletions(-)
Index: linux-2.6.33-rc4/drivers/scsi/libiscsi.c
===================================================================
--- linux-2.6.33-rc4.orig/drivers/scsi/libiscsi.c
+++ linux-2.6.33-rc4/drivers/scsi/libiscsi.c
@@ -354,7 +354,7 @@ static int iscsi_check_tmf_restrictions(
* Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
* fields like dlength or final based on how much data it sends
*/
-static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
+static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task, uint32_t
next_cmdsn)
{
struct iscsi_conn *conn = task->conn;
struct iscsi_session *session = conn->session;
@@ -475,10 +475,8 @@ static int iscsi_prep_scsi_cmd_pdu(struc
return -EIO;
task->state = ISCSI_TASK_RUNNING;
- hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
- session->cmdsn++;
+ hdr->cmdsn = task->cmdsn = cpu_to_be32(next_cmdsn);
- conn->scsicmd_pdus_cnt++;
ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
"itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
scsi_bidi_cmnd(sc) ? "bidirectional" :
@@ -1454,6 +1452,7 @@ static int iscsi_data_xmit(struct iscsi_
{
struct iscsi_task *task;
int rc = 0;
+ uint32_t next_cmdsn;
spin_lock_bh(&conn->session->lock);
if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
@@ -1497,7 +1496,10 @@ check_mgmt:
fail_scsi_task(conn->task, DID_IMM_RETRY);
continue;
}
- rc = iscsi_prep_scsi_cmd_pdu(conn->task);
+ next_cmdsn = conn->session->cmdsn;
+ conn->session->cmdsn++; /* FIXME - do it in one line of code */
+ conn->scsicmd_pdus_cnt++;
+ rc = iscsi_prep_scsi_cmd_pdu(conn->task, next_cmdsn);
if (rc) {
if (rc == -ENOMEM || rc == -EACCES) {
list_add_tail(&conn->task->running,
@@ -1607,6 +1609,7 @@ int iscsi_queuecommand(struct scsi_cmnd
struct iscsi_session *session;
struct iscsi_conn *conn;
struct iscsi_task *task = NULL;
+ uint32_t next_cmdsn;
sc->scsi_done = done;
sc->result = 0;
@@ -1683,8 +1686,14 @@ int iscsi_queuecommand(struct scsi_cmnd
}
if (!ihost->workq) {
- reason = iscsi_prep_scsi_cmd_pdu(task);
+ next_cmdsn = session->cmdsn;
+ session->cmdsn++; /* FIXME - do it in one line of code */
+ session->queued_cmdsn++;
+ conn->scsicmd_pdus_cnt++;
+ spin_unlock(&session->lock);
+ reason = iscsi_prep_scsi_cmd_pdu(task, next_cmdsn);
if (reason) {
+ spin_lock(&session->lock); /* match error flow */
if (reason == -ENOMEM || reason == -EACCES) {
reason = FAILURE_OOM;
goto prepd_reject;
@@ -1694,6 +1703,7 @@ int iscsi_queuecommand(struct scsi_cmnd
}
}
if (session->tt->xmit_task(task)) {
+ spin_lock(&session->lock); /* match error flow */
session->cmdsn--;
reason = FAILURE_SESSION_NOT_READY;
goto prepd_reject;
@@ -1701,10 +1711,10 @@ int iscsi_queuecommand(struct scsi_cmnd
} else {
list_add_tail(&task->running, &conn->cmdqueue);
iscsi_conn_queue_work(conn);
+ session->queued_cmdsn++;
+ spin_unlock(&session->lock);
}
- session->queued_cmdsn++;
- spin_unlock(&session->lock);
spin_lock(host->host_lock);
return 0;
Index: linux-2.6.33-rc4/drivers/infiniband/ulp/iser/iser_memory.c
===================================================================
--- linux-2.6.33-rc4.orig/drivers/infiniband/ulp/iser/iser_memory.c
+++ linux-2.6.33-rc4/drivers/infiniband/ulp/iser/iser_memory.c
@@ -402,8 +402,10 @@ int iser_reg_rdma_mem(struct iscsi_iser_
(unsigned long)regd_buf->reg.va,
(unsigned long)regd_buf->reg.len);
} else { /* use FMR for multiple dma entries */
+ spin_lock(&ib_conn->lock); /* protect ib_conn->page_vec */
iser_page_vec_build(mem, ib_conn->page_vec, ibdev);
err = iser_reg_page_vec(ib_conn, ib_conn->page_vec,
®d_buf->reg);
+ spin_unlock(&ib_conn->lock);
if (err) {
iser_data_buf_dump(mem, ibdev);
iser_err("mem->dma_nents = %d (dlength = 0x%x)\n",
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