From: Rob Evers <revers@xxxxxxxxxx>
Currently the backoff algorithm for when to retry alua rtpg
requests progresses geometrically as so:
2, 4, 8, 16, 32, 64... seconds.
This progression can lead to un-needed delay in retrying
alua rtpg requests when the rtpgs are delayed. A less
aggressive backoff algorithm that is additive would not
lead to such large jumps when delays start getting long, but
would backoff linearly:
2, 4, 6, 8, 10... seconds.
Signed-off-by: Rob Evers <revers@xxxxxxxxxx>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index ca414ae..e0749e9 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -522,7 +522,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
unsigned char *ucp;
unsigned err;
bool rtpg_ext_hdr_req = 1;
- unsigned long expiry, interval = 1000;
+ unsigned long expiry, interval = 0;
unsigned int tpg_desc_tbl_off;
unsigned char orig_transition_tmo;
@@ -624,7 +624,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
case TPGS_STATE_TRANSITIONING:
if (time_before(jiffies, expiry)) {
/* State transition, retry */
- interval *= 2;
+ interval += 2000;
msleep(interval);
goto retry;
}
--
1.7.7.2
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