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| author |   Rob Evers <revers@redhat.com> | 2012-05-18 14:08:56 -0400 |
|---|---|---|
| committer |   James Bottomley <JBottomley@Parallels.com> | 2012-07-20 08:58:33 +0100 |
| commit | bc97f4bb4490ff31b2be8e006f750d4187ef0c7e (patch) | |
| tree | d6099236a840c8027dca206835541dede00f63af /drivers/scsi/device_handler | |
| parent | [SCSI] scsi_dh_alua: retry alua rtpg extended header for illegal request response (diff) | |
| download | linux-dev-bc97f4bb4490ff31b2be8e006f750d4187ef0c7e.tar.xz linux-dev-bc97f4bb4490ff31b2be8e006f750d4187ef0c7e.zip | |
[SCSI] scsi_dh_alua: backoff alua rtpg retry linearly vs. geometrically
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: Martin George <marting@netapp.com>
Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/device_handler')
| -rw-r--r-- | 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 5a3448856962..0d573822bf43 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -527,7 +527,7 @@ 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; @@ -632,7 +632,7 @@ 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; } |