aoe: add module parameter for users who need more outstanding I/O
An AoE target provides an estimate of the number of outstanding commands that
the AoE initiator can send before getting a response. The aoe_maxout
parameter provides a way to set an even lower limit. It will not allow a user
to use more outstanding commands than the target permits. If a user discovers
a problem with a large setting, this parameter provides a way for us to work
with them to debug the problem. We expect to improve the dynamic window
sizing algorithm and drop this parameter. For the time being, it is a
debugging aid.
Signed-off-by: Ed L. Cashin <ecashin@coraid.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 7a96183..e92d885 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -18,6 +18,11 @@
module_param(aoe_deadsecs, int, 0644);
MODULE_PARM_DESC(aoe_deadsecs, "After aoe_deadsecs seconds, give up and fail dev.");
+static int aoe_maxout = 16;
+module_param(aoe_maxout, int, 0644);
+MODULE_PARM_DESC(aoe_maxout,
+ "Only aoe_maxout outstanding packets for every MAC on eX.Y.");
+
static struct sk_buff *
new_skb(ulong len)
{
@@ -984,7 +989,6 @@
struct aoeif *ifp;
ulong flags, sysminor, aoemajor;
struct sk_buff *sl;
- enum { MAXFRAMES = 16 };
u16 n;
h = (struct aoe_hdr *) skb_mac_header(skb);
@@ -1009,8 +1013,8 @@
}
n = be16_to_cpu(ch->bufcnt);
- if (n > MAXFRAMES) /* keep it reasonable */
- n = MAXFRAMES;
+ if (n > aoe_maxout) /* keep it reasonable */
+ n = aoe_maxout;
d = aoedev_by_sysminor_m(sysminor);
if (d == NULL) {