Commit dced3a05 authored by Ed L. Cashin's avatar Ed L. Cashin Committed by Greg Kroah-Hartman
Browse files

aoe: improve retransmission heuristics



Add a dynamic minimum timer for better retransmission behavior.

Signed-off-by: default avatar"Ed L. Cashin" <ecashin@coraid.com>
Acked-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ddec63e8
......@@ -125,8 +125,10 @@ struct aoedev {
ulong sysminor;
ulong aoemajor;
ulong aoeminor;
ulong nopen; /* (bd_openers isn't available without sleeping) */
ulong rttavg; /* round trip average of requests/responses */
u16 nopen; /* (bd_openers isn't available without sleeping) */
u16 lasttag; /* last tag sent */
u16 rttavg; /* round trip average of requests/responses */
u16 mintimer;
u16 fw_ver; /* version of blade's firmware */
u16 maxbcnt;
struct work_struct work;/* disk create work struct */
......@@ -142,7 +144,6 @@ struct aoedev {
mempool_t *bufpool; /* for deadlock-free Buf allocation */
struct list_head bufq; /* queue of bios to work on */
struct buf *inprocess; /* the one we're currently working on */
ulong lasttag; /* last tag sent */
ushort lostjumbo;
ushort nframes; /* number of frames below */
struct frame *frames;
......
......@@ -461,8 +461,15 @@ calc_rttavg(struct aoedev *d, int rtt)
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 @@ aoecmd_ata_rsp(struct sk_buff *skb)
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 @@ aoecmd_cfg_rsp(struct sk_buff *skb)
return;
}
d->flags |= DEVFL_PAUSE; /* force pause */
d->mintimer = MINTIMER;
d->fw_ver = be16_to_cpu(ch->fwver);
/* check for already outstanding ataid */
......
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