On Wed, 2021-01-27 at 19:23 +0100, Paolo Bonzini wrote:
> On 27/01/21 18:25, Joe Perches wrote:
> >
> > -#ifdef MMU_DEBUG
> > -bool dbg = 0;
> > -module_param(dbg, bool, 0644);
> > -#endif
> > -
> > #define PTE_PREFETCH_NUM 8
> >
> >
> > #define PT32_LEVEL_BITS 10
> > @@ -844,17 +839,17 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64
> > *spte,
> > int i, count = 0;
> >
> >
> > if (!rmap_head->val) {
> > - rmap_printk("pte_list_add: %p %llx 0->1\n", spte, *spte);
> > + pr_debug("%p %llx 0->1\n", spte, *spte);
> > rmap_head->val = (unsigned long)spte;
> > } else if (!(rmap_head->val & 1)) {
> > - rmap_printk("pte_list_add: %p %llx 1->many\n", spte, *spte);
> > + pr_debug("%p %llx 1->many\n", spte, *spte);
> > desc = mmu_alloc_pte_list_desc(vcpu);
>
> This would be extremely slow. These messages are even too verbose for
> tracepoints.
There's no real object change.
It's not enabled unless DEBUG is defined (and it's not enabled by default)
or CONFIG_DYNAMIC_DEBUG is enabled and then dynamic_debug jump points are
used when not enabled so I think any slowdown, even when dynamic_debug is
enabled is trivial.
