Jan Beulich
2011-Oct-13 07:16 UTC
[Xen-devel] [PATCH] constify vcpu_set_affinity()''s second parameter
None of the callers actually make use of the function''s returning of
the old affinity through its second parameter, and eliminating this
capability allows some callers to no longer use a local variable here,
reducing their stack footprint significantly when building with large
NR_CPUS.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/cpu/mcheck/vmce.c
+++ b/xen/arch/x86/cpu/mcheck/vmce.c
@@ -304,7 +304,6 @@ int vmce_wrmsr(u32 msr, u64 val)
int inject_vmce(struct domain *d)
{
int cpu = smp_processor_id();
- cpumask_t affinity;
/* PV guest and HVM guest have different vMCE# injection methods. */
if ( !test_and_set_bool(d->vcpu[0]->mce_pending) )
@@ -323,11 +322,9 @@ int inject_vmce(struct domain *d)
{
cpumask_copy(d->vcpu[0]->cpu_affinity_tmp,
d->vcpu[0]->cpu_affinity);
- cpus_clear(affinity);
- cpu_set(cpu, affinity);
mce_printk(MCE_VERBOSE, "MCE: CPU%d set affinity, old
%d\n",
cpu, d->vcpu[0]->processor);
- vcpu_set_affinity(d->vcpu[0], &affinity);
+ vcpu_set_affinity(d->vcpu[0], cpumask_of(cpu));
vcpu_kick(d->vcpu[0]);
}
else
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -3113,7 +3113,6 @@ static void nmi_mce_softirq(void)
{
int cpu = smp_processor_id();
struct softirq_trap *st = &per_cpu(softirq_trap, cpu);
- cpumask_t affinity;
BUG_ON(st == NULL);
BUG_ON(st->vcpu == NULL);
@@ -3129,9 +3128,7 @@ static void nmi_mce_softirq(void)
* Make sure to wakeup the vcpu on the
* specified processor.
*/
- cpus_clear(affinity);
- cpu_set(st->processor, affinity);
- vcpu_set_affinity(st->vcpu, &affinity);
+ vcpu_set_affinity(st->vcpu, cpumask_of(st->processor));
/* Affinity is restored in the iret hypercall. */
}
@@ -3201,14 +3198,11 @@ void async_exception_cleanup(struct vcpu
!test_and_set_bool(curr->mce_pending) )
{
int cpu = smp_processor_id();
- cpumask_t affinity;
cpumask_copy(curr->cpu_affinity_tmp, curr->cpu_affinity);
- cpus_clear(affinity);
- cpu_set(cpu, affinity);
printk(XENLOG_DEBUG "MCE: CPU%d set affinity, old
%d\n",
cpu, curr->processor);
- vcpu_set_affinity(curr, &affinity);
+ vcpu_set_affinity(curr, cpumask_of(cpu));
}
}
}
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -587,9 +587,9 @@ int cpu_disable_scheduler(unsigned int c
return ret;
}
-int vcpu_set_affinity(struct vcpu *v, cpumask_t *affinity)
+int vcpu_set_affinity(struct vcpu *v, const cpumask_t *affinity)
{
- cpumask_t online_affinity, old_affinity;
+ cpumask_t online_affinity;
cpumask_t *online;
if ( v->domain->is_pinned )
@@ -601,9 +601,7 @@ int vcpu_set_affinity(struct vcpu *v, cp
vcpu_schedule_lock_irq(v);
- cpumask_copy(&old_affinity, v->cpu_affinity);
cpumask_copy(v->cpu_affinity, affinity);
- cpumask_copy(affinity, &old_affinity);
if ( !cpumask_test_cpu(v->processor, v->cpu_affinity) )
set_bit(_VPF_migrating, &v->pause_flags);
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -617,7 +617,7 @@ void scheduler_free(struct scheduler *sc
int schedule_cpu_switch(unsigned int cpu, struct cpupool *c);
void vcpu_force_reschedule(struct vcpu *v);
int cpu_disable_scheduler(unsigned int cpu);
-int vcpu_set_affinity(struct vcpu *v, cpumask_t *affinity);
+int vcpu_set_affinity(struct vcpu *v, const cpumask_t *affinity);
void vcpu_runstate_get(struct vcpu *v, struct vcpu_runstate_info *runstate);
uint64_t get_cpu_idle_time(unsigned int cpu);
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel
Keir Fraser
2011-Oct-13 07:45 UTC
Re: [Xen-devel] [PATCH] constify vcpu_set_affinity()''s second parameter
Acked-by: Keir Fraser <keir@xen.org> On 13/10/2011 08:16, "Jan Beulich" <JBeulich@suse.com> wrote:> None of the callers actually make use of the function''s returning of > the old affinity through its second parameter, and eliminating this > capability allows some callers to no longer use a local variable here, > reducing their stack footprint significantly when building with large > NR_CPUS. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> > > --- a/xen/arch/x86/cpu/mcheck/vmce.c > +++ b/xen/arch/x86/cpu/mcheck/vmce.c > @@ -304,7 +304,6 @@ int vmce_wrmsr(u32 msr, u64 val) > int inject_vmce(struct domain *d) > { > int cpu = smp_processor_id(); > - cpumask_t affinity; > > /* PV guest and HVM guest have different vMCE# injection methods. */ > if ( !test_and_set_bool(d->vcpu[0]->mce_pending) ) > @@ -323,11 +322,9 @@ int inject_vmce(struct domain *d) > { > cpumask_copy(d->vcpu[0]->cpu_affinity_tmp, > d->vcpu[0]->cpu_affinity); > - cpus_clear(affinity); > - cpu_set(cpu, affinity); > mce_printk(MCE_VERBOSE, "MCE: CPU%d set affinity, old %d\n", > cpu, d->vcpu[0]->processor); > - vcpu_set_affinity(d->vcpu[0], &affinity); > + vcpu_set_affinity(d->vcpu[0], cpumask_of(cpu)); > vcpu_kick(d->vcpu[0]); > } > else > --- a/xen/arch/x86/traps.c > +++ b/xen/arch/x86/traps.c > @@ -3113,7 +3113,6 @@ static void nmi_mce_softirq(void) > { > int cpu = smp_processor_id(); > struct softirq_trap *st = &per_cpu(softirq_trap, cpu); > - cpumask_t affinity; > > BUG_ON(st == NULL); > BUG_ON(st->vcpu == NULL); > @@ -3129,9 +3128,7 @@ static void nmi_mce_softirq(void) > * Make sure to wakeup the vcpu on the > * specified processor. > */ > - cpus_clear(affinity); > - cpu_set(st->processor, affinity); > - vcpu_set_affinity(st->vcpu, &affinity); > + vcpu_set_affinity(st->vcpu, cpumask_of(st->processor)); > > /* Affinity is restored in the iret hypercall. */ > } > @@ -3201,14 +3198,11 @@ void async_exception_cleanup(struct vcpu > !test_and_set_bool(curr->mce_pending) ) > { > int cpu = smp_processor_id(); > - cpumask_t affinity; > > cpumask_copy(curr->cpu_affinity_tmp, curr->cpu_affinity); > - cpus_clear(affinity); > - cpu_set(cpu, affinity); > printk(XENLOG_DEBUG "MCE: CPU%d set affinity, old %d\n", > cpu, curr->processor); > - vcpu_set_affinity(curr, &affinity); > + vcpu_set_affinity(curr, cpumask_of(cpu)); > } > } > } > --- a/xen/common/schedule.c > +++ b/xen/common/schedule.c > @@ -587,9 +587,9 @@ int cpu_disable_scheduler(unsigned int c > return ret; > } > > -int vcpu_set_affinity(struct vcpu *v, cpumask_t *affinity) > +int vcpu_set_affinity(struct vcpu *v, const cpumask_t *affinity) > { > - cpumask_t online_affinity, old_affinity; > + cpumask_t online_affinity; > cpumask_t *online; > > if ( v->domain->is_pinned ) > @@ -601,9 +601,7 @@ int vcpu_set_affinity(struct vcpu *v, cp > > vcpu_schedule_lock_irq(v); > > - cpumask_copy(&old_affinity, v->cpu_affinity); > cpumask_copy(v->cpu_affinity, affinity); > - cpumask_copy(affinity, &old_affinity); > if ( !cpumask_test_cpu(v->processor, v->cpu_affinity) ) > set_bit(_VPF_migrating, &v->pause_flags); > > --- a/xen/include/xen/sched.h > +++ b/xen/include/xen/sched.h > @@ -617,7 +617,7 @@ void scheduler_free(struct scheduler *sc > int schedule_cpu_switch(unsigned int cpu, struct cpupool *c); > void vcpu_force_reschedule(struct vcpu *v); > int cpu_disable_scheduler(unsigned int cpu); > -int vcpu_set_affinity(struct vcpu *v, cpumask_t *affinity); > +int vcpu_set_affinity(struct vcpu *v, const cpumask_t *affinity); > > void vcpu_runstate_get(struct vcpu *v, struct vcpu_runstate_info *runstate); > uint64_t get_cpu_idle_time(unsigned int cpu); > > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel