Re: [patch] sched: fix macro -> inline function conversion bug

[Ingo Molnar]

* Ingo Molnar <mingo@xxxxxxx> wrote:

> > Did you work out which divide is getting the div-by-zero?  I started 
> > at it a bit and wasn't sure - am getting wildly different code 
> > generation over here.
> 
> my bet is on sched-group-cpu-power-setup-cleanup.patch.

in particular, we dont seem to initialize ->cpu_power properly. Martin, 
does the patch below solve your crash?

	Ingo

-------------->
Subject: sched: group cpu power setup cleanup, fix
From: Ingo Molnar <mingo@xxxxxxx>

- fix missing initialization of ->cpu_power
- clean up the cleanup

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
 include/linux/sched.h |    2 +-
 kernel/sched.c        |    9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

Index: linux/include/linux/sched.h
===================================================================
--- linux.orig/include/linux/sched.h
+++ linux/include/linux/sched.h
@@ -636,7 +636,7 @@ enum idle_type
 	((sched_mc_power_savings || sched_smt_power_savings) ?	\
 					SD_POWERSAVINGS_BALANCE : 0)
 
-#define test_sd_flag(sd, flag)	((sd && sd->flags & flag) ? 1 : 0)
+#define test_sd_flag(sd, flag)	((sd && (sd->flags & flag)) ? 1 : 0)
 
 
 struct sched_group {
Index: linux/kernel/sched.c
===================================================================
--- linux.orig/kernel/sched.c
+++ linux/kernel/sched.c
@@ -1292,7 +1292,7 @@ static int sched_balance_self(int cpu, i
 		cpu = new_cpu;
 nextlevel:
 		sd = sd->child;
-		if (sd && sd->flags & flag)
+		if (test_sd_flag(sd, flag))
 			goto nextlevel;
 		/* while loop will break here if sd == NULL */
 	}
@@ -6224,6 +6224,7 @@ static int cpu_to_allnodes_group(int cpu
 {
 	return cpu_to_node(cpu);
 }
+
 static void init_numa_sched_groups_power(struct sched_group *group_head)
 {
 	struct sched_group *sg = group_head;
@@ -6314,8 +6315,12 @@ static void init_sched_groups_power(int 
 	struct sched_domain *child;
 	struct sched_group *group;
 
-	if (!sd || !sd->groups || (cpu != first_cpu(sd->groups->cpumask)))
+	WARN_ON(!sd || !sd->groups);
+
+	if (cpu != first_cpu(sd->groups->cpumask)) {
+		sd->groups->cpu_power = SCHED_LOAD_SCALE;
 		return;
+	}
 
 	child = sd->child;
 
-
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