Author: mav
Date: Sat Nov 22 09:05:54 2014
New Revision: 274843
URL: https://svnweb.freebsd.org/changeset/base/274843
Log:
Move icl_pdu_get_data() and xpt_done() out of initiator's session lock.
During heavy reads data copying in icl_pdu_get_data() may consume large
percent of CPU time. Moving it out of the lock significantly reduces
lock hold time and respectively lock congestion on read operations.
MFC after: 2 weeks
Modified:
head/sys/dev/iscsi/iscsi.c
Modified: head/sys/dev/iscsi/iscsi.c
==============================================================================
--- head/sys/dev/iscsi/iscsi.c Sat Nov 22 08:47:04 2014 (r274842)
+++ head/sys/dev/iscsi/iscsi.c Sat Nov 22 09:05:54 2014 (r274843)
@@ -139,6 +139,7 @@ static uma_zone_t iscsi_outstanding_zone
#define ISCSI_SESSION_LOCK(X) mtx_lock(&X->is_lock)
#define ISCSI_SESSION_UNLOCK(X) mtx_unlock(&X->is_lock)
#define ISCSI_SESSION_LOCK_ASSERT(X) mtx_assert(&X->is_lock, MA_OWNED)
+#define ISCSI_SESSION_LOCK_ASSERT_NOT(X) mtx_assert(&X->is_lock, MA_NOTOWNED)
static int iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg,
int mode, struct thread *td);
@@ -709,37 +710,46 @@ iscsi_receive_callback(struct icl_pdu *r
switch (response->ip_bhs->bhs_opcode) {
case ISCSI_BHS_OPCODE_NOP_IN:
iscsi_pdu_handle_nop_in(response);
+ ISCSI_SESSION_UNLOCK(is);
break;
case ISCSI_BHS_OPCODE_SCSI_RESPONSE:
iscsi_pdu_handle_scsi_response(response);
+ /* Session lock dropped inside. */
+ ISCSI_SESSION_LOCK_ASSERT_NOT(is);
break;
case ISCSI_BHS_OPCODE_TASK_RESPONSE:
iscsi_pdu_handle_task_response(response);
+ ISCSI_SESSION_UNLOCK(is);
break;
case ISCSI_BHS_OPCODE_SCSI_DATA_IN:
iscsi_pdu_handle_data_in(response);
+ /* Session lock dropped inside. */
+ ISCSI_SESSION_LOCK_ASSERT_NOT(is);
break;
case ISCSI_BHS_OPCODE_LOGOUT_RESPONSE:
iscsi_pdu_handle_logout_response(response);
+ ISCSI_SESSION_UNLOCK(is);
break;
case ISCSI_BHS_OPCODE_R2T:
iscsi_pdu_handle_r2t(response);
+ ISCSI_SESSION_UNLOCK(is);
break;
case ISCSI_BHS_OPCODE_ASYNC_MESSAGE:
iscsi_pdu_handle_async_message(response);
+ ISCSI_SESSION_UNLOCK(is);
break;
case ISCSI_BHS_OPCODE_REJECT:
iscsi_pdu_handle_reject(response);
+ ISCSI_SESSION_UNLOCK(is);
break;
default:
ISCSI_SESSION_WARN(is, "received PDU with unsupported "
"opcode 0x%x; reconnecting",
response->ip_bhs->bhs_opcode);
iscsi_session_reconnect(is);
+ ISCSI_SESSION_UNLOCK(is);
icl_pdu_free(response);
}
-
- ISCSI_SESSION_UNLOCK(is);
}
static void
@@ -840,9 +850,13 @@ iscsi_pdu_handle_scsi_response(struct ic
ISCSI_SESSION_WARN(is, "bad itt 0x%x",
bhssr->bhssr_initiator_task_tag);
icl_pdu_free(response);
iscsi_session_reconnect(is);
+ ISCSI_SESSION_UNLOCK(is);
return;
}
+ iscsi_outstanding_remove(is, io);
+ ISCSI_SESSION_UNLOCK(is);
+
if (bhssr->bhssr_response != BHSSR_RESPONSE_COMMAND_COMPLETED) {
ISCSI_SESSION_WARN(is, "service response 0x%x",
bhssr->bhssr_response);
if ((io->io_ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
@@ -861,15 +875,7 @@ iscsi_pdu_handle_scsi_response(struct ic
io->io_ccb->csio.scsi_status = bhssr->bhssr_status;
}
- if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_OVERFLOW) {
- ISCSI_SESSION_WARN(is, "target indicated residual overflow");
- icl_pdu_free(response);
- iscsi_session_reconnect(is);
- return;
- }
-
csio = &io->io_ccb->csio;
-
data_segment_len = icl_pdu_data_segment_length(response);
if (data_segment_len > 0) {
if (data_segment_len < sizeof(sense_len)) {
@@ -931,7 +937,6 @@ out:
}
xpt_done(io->io_ccb);
- iscsi_outstanding_remove(is, io);
icl_pdu_free(response);
}
@@ -974,7 +979,7 @@ iscsi_pdu_handle_data_in(struct icl_pdu
struct iscsi_outstanding *io;
struct iscsi_session *is;
struct ccb_scsiio *csio;
- size_t data_segment_len;
+ size_t data_segment_len, received;
is = PDU_SESSION(response);
bhsdi = (struct iscsi_bhs_data_in *)response->ip_bhs;
@@ -983,6 +988,7 @@ iscsi_pdu_handle_data_in(struct icl_pdu
ISCSI_SESSION_WARN(is, "bad itt 0x%x",
bhsdi->bhsdi_initiator_task_tag);
icl_pdu_free(response);
iscsi_session_reconnect(is);
+ ISCSI_SESSION_UNLOCK(is);
return;
}
@@ -993,6 +999,7 @@ iscsi_pdu_handle_data_in(struct icl_pdu
* but initiators and targets MUST be able to properly receive
* 0 length data segments."
*/
+ ISCSI_SESSION_UNLOCK(is);
icl_pdu_free(response);
return;
}
@@ -1007,6 +1014,7 @@ iscsi_pdu_handle_data_in(struct icl_pdu
io->io_received, (size_t)ntohl(bhsdi->bhsdi_buffer_offset));
icl_pdu_free(response);
iscsi_session_reconnect(is);
+ ISCSI_SESSION_UNLOCK(is);
return;
}
@@ -1018,11 +1026,17 @@ iscsi_pdu_handle_data_in(struct icl_pdu
data_segment_len, io->io_received, csio->dxfer_len);
icl_pdu_free(response);
iscsi_session_reconnect(is);
+ ISCSI_SESSION_UNLOCK(is);
return;
}
- icl_pdu_get_data(response, 0, csio->data_ptr + io->io_received,
data_segment_len);
+ received = io->io_received;
io->io_received += data_segment_len;
+ if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0)
+ iscsi_outstanding_remove(is, io);
+ ISCSI_SESSION_UNLOCK(is);
+
+ icl_pdu_get_data(response, 0, csio->data_ptr + received,
data_segment_len);
/*
* XXX: Check DataSN.
@@ -1064,7 +1078,6 @@ iscsi_pdu_handle_data_in(struct icl_pdu
}
xpt_done(io->io_ccb);
- iscsi_outstanding_remove(is, io);
icl_pdu_free(response);
}
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
