Re: [Patch] Overload flag is not resetting

[Horms <horms@xxxxxxxxxxxx>]

On Fri, Feb 04, 2005 at 10:55:59AM +0200, Julian Anastasov wrote:
> 
>       Hello,
> 
>       I'm periodically unsubscribed from this lists (due to 
> bounces?) while subscriptions to other lists are still alive and
> sometimes i'm missing interesting topics.
> 
>       Can you change WRR on update instead of setting mark->cw to 0,
> to clamp it to mw, sort of:
> 
> if (mark->cw > mark->mw)
>       mark->cw = mark->mw;

That probably is a slightly smarter approach.
As it happens, it ends up being set to mark->mw a bit
later if we reset it to 0. But your idea would allow
it to stay at its existing value if it is still valid
for the new mw.

> 
>       By this way we preserve the weight distribution without
> restarting it on update.
> 
>       Can this fix a problem where on reducing the max weight
> no dests are returned until cw reaches down to mw.

Yes, I am pretty sure that problem would be resolved.
Either with the previous two patches (which both set mark->cw to 0),
or the one below which implements your idea.

-- 
Horms

===== net/ipv4/ipvs/ip_vs_wrr.c 1.5 vs edited =====
--- 1.5/net/ipv4/ipvs/ip_vs_wrr.c       2004-02-19 06:03:53 +09:00
+++ edited/net/ipv4/ipvs/ip_vs_wrr.c    2005-02-04 18:58:29 +09:00
@@ -25,6 +25,8 @@
 
 #include <net/ip_vs.h>
 
+static int ip_vs_wrr_update_svc(struct ip_vs_service *svc);
+
 /*
  * current destination pointer for weighted round-robin scheduling
  */
@@ -98,11 +100,9 @@ static int ip_vs_wrr_init_svc(struct ip_
                IP_VS_ERR("ip_vs_wrr_init_svc(): no memory\n");
                return -ENOMEM;
        }
-       mark->cl = &svc->destinations;
        mark->cw = 0;
-       mark->mw = ip_vs_wrr_max_weight(svc);
-       mark->di = ip_vs_wrr_gcd_weight(svc);
        svc->sched_data = mark;
+       ip_vs_wrr_update_svc(svc);
 
        return 0;
 }
@@ -124,6 +124,8 @@ static int ip_vs_wrr_update_svc(struct i
        struct ip_vs_wrr_mark *mark = svc->sched_data;
 
        mark->cl = &svc->destinations;
+       if (mark->cw > mark->mw)
+                mark->cw = mark->mw;
        mark->mw = ip_vs_wrr_max_weight(svc);
        mark->di = ip_vs_wrr_gcd_weight(svc);
        return 0;