Re: mmap hw behavior

Michal Simek
2009-07-08T18:03:42Z

> Date: Wed, 08 Jul 2009 19:03:11 +0200
>
>
>> When I call mmap for that open file with pointer to calloc place
>> (first parameter, + length zero) it should be one tlb invalidation
>> for calloc and new tlb which connect open file. We check it and we
>> don't have any tlb invalidation that's why I think that kernel do
>> different thigs. Or is it there any copying? Or anything different?
>>
>
> There is no need to tlb flush the calloc area unless that memory area
> is actually touched by the user application and thus the page is
> faulted in.
>
That calloc area is filled by any value (in that test). Is it mean that
for this case when calloc area is touched
there must be tlb invalidation + remapping?