aoe: improve retransmission heuristics
Add a dynamic minimum timer for better retransmission behavior.
Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 621fdbb..c0bdc1f 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -461,8 +461,15 @@
register long n;
n = rtt;
- if (n < MINTIMER)
- n = MINTIMER;
+ if (n < 0) {
+ n = -rtt;
+ if (n < MINTIMER)
+ n = MINTIMER;
+ else if (n > MAXTIMER)
+ n = MAXTIMER;
+ d->mintimer += (n - d->mintimer) >> 1;
+ } else if (n < d->mintimer)
+ n = d->mintimer;
else if (n > MAXTIMER)
n = MAXTIMER;
@@ -498,8 +505,10 @@
spin_lock_irqsave(&d->lock, flags);
- f = getframe(d, be32_to_cpu(hin->tag));
+ n = be32_to_cpu(hin->tag);
+ f = getframe(d, n);
if (f == NULL) {
+ calc_rttavg(d, -tsince(n));
spin_unlock_irqrestore(&d->lock, flags);
snprintf(ebuf, sizeof ebuf,
"%15s e%d.%d tag=%08x@%08lx\n",
@@ -724,6 +733,7 @@
return;
}
d->flags |= DEVFL_PAUSE; /* force pause */
+ d->mintimer = MINTIMER;
d->fw_ver = be16_to_cpu(ch->fwver);
/* check for already outstanding ataid */