[PATCH 2/2] autonuma: fix typo in blind balance

[PATCH 2/2] autonuma: fix typo in blind balance

[Hillf Danton]

Since it is certain that nid is not online in each round of for-loop,
it is replaced with given node id.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
---

--- a/kernel/sched/numa.c	Sat Mar 17 11:01:40 2012
+++ b/kernel/sched/numa.c	Mon Mar 19 20:04:00 2012
@@ -34,7 +34,7 @@ static int autonuma_balance_blind(struct
 		selected_nid = cpu_nid;

 		nr_mm_max = 0;
-		for_each_cpu_and(cpu, cpumask_of_node(nid), allowed) {
+		for_each_cpu_and(cpu, cpumask_of_node(cpu_nid), allowed) {
 			struct rq *rq = cpu_rq(cpu);
 			if (rq->curr->mm == mm)
 				nr_mm_max++;
--

Re: [PATCH 2/2] autonuma: fix typo in blind balance

[Andrea Arcangeli]

On Mon, Mar 19, 2012 at 08:59:59PM +0800, Hillf Danton wrote:
> Since it is certain that nid is not online in each round of for-loop,
> it is replaced with given node id.
> 
> Signed-off-by: Hillf Danton <dhillf@gmail.com>
> ---
> 
> --- a/kernel/sched/numa.c	Sat Mar 17 11:01:40 2012
> +++ b/kernel/sched/numa.c	Mon Mar 19 20:04:00 2012
> @@ -34,7 +34,7 @@ static int autonuma_balance_blind(struct
>  		selected_nid = cpu_nid;
> 
>  		nr_mm_max = 0;
> -		for_each_cpu_and(cpu, cpumask_of_node(nid), allowed) {
> +		for_each_cpu_and(cpu, cpumask_of_node(cpu_nid), allowed) {
>  			struct rq *rq = cpu_rq(cpu);
>  			if (rq->curr->mm == mm)
>  				nr_mm_max++;

Correct! gcc should have spwaned an unintialized warning too? I may
have broke it by accident with the editor after I disabled the
function. AUTONUMA_BALANCE_BLIND is not set so this function isn't
getting built right now.

I tried to keep enabled only the minimum, kind of stuff that if you
remove it, something will degrade significantly. 

With the algorithms I developed before the current
sched_autonuma_balance, having autonuma_balance_blind made huge
difference, not anymore once I had something way better as a core
balancer, so then I considered autonuma_balance_blind more like an
hack and I disabled it.

I'm impressed how fast you found these two bugs, appreciated!

If you've high level opinions on the design, comments welcome.

Thanks,
Andrea