Re: [patch -mm 1/2] i386: add ptep_test_and_clear_{dirty,young}

[David Rientjes]

On Sun, 25 Mar 2007, Zachary Amsden wrote:

> If you actually clear the bit, you need to:
> 
> +         pte_update_defer(vma->vm_mm, addr, ptep);
> 
> The reason is, when updating PTEs, the hypervisor must be notified.  Using
> atomic operations to do this is fine for all hypervisors I am aware of.
> However, for hypervisors which shadow page tables, if these PTE modifications
> are not trapped, you need a post-modification call to fulfill the update of
> the shadow page table.
> 

Then why was ptep_test_and_clear_{dirty,young} ever removed in the first 
place??  To gain the optimization of one fewer branch and introduce a hack 
to advertise it's existance so the generic header file doesn't include its 
own version?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/