Re: [PATCH] Cosmetic change to schedule_cpu_switch

[Keir Fraser <keir.fraser@eu.citrix.com>]

On 19/05/2010 09:19, "Keir Fraser" <keir.fraser@eu.citrix.com> wrote:

> Thanks, I'll fold this into my next patch. You'll see from my recent
> changesets that I'm currently tearing into the scheduler and cpupool code as
> part of my CPU hotplug cleanup.

I'm finished as of xen-unstable:21422, by the way.

 -- Keir

> I think there must be scope for further
> rationalisation of the sched-if interfaces as the sched_ops have sprouted a
> bewildering array of extra functions for cpupool support. I'm sure it's over
> complicated.
> 
>  -- Keir
> 
> On 18/05/2010 21:22, "George Dunlap" <George.Dunlap@eu.citrix.com> wrote:
> 
>> Using 'v' generally means that you mean any generic vcpu, not
>> a particular vcpu.  In this case, we always use the idle vcpu;
>> I think naming it explicitly idle_vcpu makes the code easier to grok.
>> 
>> No functional changes.
>> 
>> Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
>> 
>> diff -r c6db509d7e46 -r ebad6ba33a8f xen/common/schedule.c
>> --- a/xen/common/schedule.c Tue May 18 15:18:26 2010 +0100
>> +++ b/xen/common/schedule.c Tue May 18 15:22:27 2010 -0500
>> @@ -1151,7 +1151,7 @@
>>  void schedule_cpu_switch(unsigned int cpu, struct cpupool *c)
>>  {
>>      unsigned long flags;
>> -    struct vcpu *v;
>> +    struct vcpu *idle_vcpu;
>>      void *ppriv, *ppriv_old, *vpriv = NULL;
>>      struct scheduler *old_ops = per_cpu(scheduler, cpu);
>>      struct scheduler *new_ops = (c == NULL) ? &ops : c->sched;
>> @@ -1159,21 +1159,21 @@
>>      if ( old_ops == new_ops )
>>          return;
>>  
>> -    v = per_cpu(schedule_data, cpu).idle;
>> +    idle_vcpu = per_cpu(schedule_data, cpu).idle;
>>      ppriv = SCHED_OP(new_ops, alloc_pdata, cpu);
>>      if ( c != NULL )
>> -        vpriv = SCHED_OP(new_ops, alloc_vdata, v, v->domain->sched_priv);
>> +        vpriv = SCHED_OP(new_ops, alloc_vdata, idle_vcpu,
>> idle_vcpu->domain->sched_priv);
>>  
>>      spin_lock_irqsave(per_cpu(schedule_data, cpu).schedule_lock, flags);
>>  
>>      if ( c == NULL )
>>      {
>> -        vpriv = v->sched_priv;
>> -        v->sched_priv = per_cpu(schedule_data, cpu).sched_idlevpriv;
>> +        vpriv = idle_vcpu->sched_priv;
>> +        idle_vcpu->sched_priv = per_cpu(schedule_data, cpu).sched_idlevpriv;
>>      }
>>      else
>>      {
>> -        v->sched_priv = vpriv;
>> +        idle_vcpu->sched_priv = vpriv;
>>          vpriv = NULL;
>>      }
>>      SCHED_OP(old_ops, tick_suspend, cpu);
>> @@ -1181,7 +1181,7 @@
>>      ppriv_old = per_cpu(schedule_data, cpu).sched_priv;
>>      per_cpu(schedule_data, cpu).sched_priv = ppriv;
>>      SCHED_OP(new_ops, tick_resume, cpu);
>> -    SCHED_OP(new_ops, insert_vcpu, v);
>> +    SCHED_OP(new_ops, insert_vcpu, idle_vcpu);
>>  
>>      spin_unlock_irqrestore(per_cpu(schedule_data, cpu).schedule_lock,
>> flags);
>>  
>> 
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>