lkml.org 
[lkml]   [2006]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRE: [patch] fix ia64 hugetlb_free_pgd_range
Date
From
David Gibson wrote on Thursday, February 23, 2006 8:06 PM
> But I don't see how not transforming them sometimes can be correct.
> Suppose 'floor' is only a little way below 'addr' - addr will be
> shifted down, but floor won't, so floor may now be above addr, which
> will cause weird results.
>
> Afaict the *only* thing floor and ceiling are used for is bounds
> checking the address range we're examining. How can that ever be
> right if one address has been scaled down, but the other hasn't.

The scale down isn't exactly on every address bits. Top 3 bits of
virtual address are preserved.

#define htlbpage_to_page(x) (((unsigned long) REGION_NUMBER(x) << 61)
| (REGION_OFFSET(x) >>
(HPAGE_SHIFT-PAGE_SHIFT)))

So scaled address for a hugetlb address will never be below unscaled
normal page address. That is adjusted addr will never below unchanged
floor.

- Ken
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-02-24 07:33    [W:0.071 / U:0.628 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site