mm/memory.c: Missing pte_mkyoung() on mk_pte() calls?

mm/memory.c: Missing pte_mkyoung() on mk_pte() calls?

[Marcelo Tosatti]

Linus,

I was looking at mm/memory.c (2.4), and I've noticed that we don't call
pte_mkyoung() on newly created pte's for most of the fault paths.
break_cow(), for example:

 establish_pte(vma, address, page_table, pte_mkwrite(pte_mkdirty(mk_pte(new_page, v ma->vm_page_prot))));

Is there any reason why we don't set the young bit on such places ?

I don't think that the window between the pte creation and the actual
access of the pte by the process is always big enough to avoid kswapd (or
other task trying to free memory) from ripping a created pte. 

Re: mm/memory.c: Missing pte_mkyoung() on mk_pte() calls?

[Marcelo Tosatti]

Two seconds after I sent the message Benjamin told me on IRC that
PAGE_ACCESSED is included in the default page protections... duh. 


On Thu, 17 May 2001, Marcelo Tosatti wrote:

> 
> Linus,
> 
> I was looking at mm/memory.c (2.4), and I've noticed that we don't call
> pte_mkyoung() on newly created pte's for most of the fault paths.
> break_cow(), for example:
> 
>  establish_pte(vma, address, page_table, pte_mkwrite(pte_mkdirty(mk_pte(new_page, v ma->vm_page_prot))));
> 
> Is there any reason why we don't set the young bit on such places ?
> 
> I don't think that the window between the pte creation and the actual
> access of the pte by the process is always big enough to avoid kswapd (or
> other task trying to free memory) from ripping a created pte. 
> 
> 
> 
>