[lkml]   [2006]   [Jun]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] hugetlb: powerpc: Actively close unused htlb regions on vma close
On Fri, 2 Jun 2006, Adam Litke wrote:

> The following patch introduces a architecture-specific vm_ops.close()
> hook. For all architectures besides powerpc, this is a no-op. On
> powerpc, the low and high segments are scanned to locate empty hugetlb
> segments which can be made available for normal mappings. Comments?

IA64 has similar issues and uses the hook suggested by Hugh. However, we
have a permanently reserved memory area. I am a bit surprised about the
need to make address space available for normal mappings. Is this for 32
bit powerpc support?

void hugetlb_free_pgd_range(struct mmu_gather **tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
* This is called to free hugetlb page tables.
* The offset of these addresses from the base of the hugetlb
* region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
* the standard free_pgd_range will free the right page tables.
* If floor and ceiling are also in the hugetlb region, they
* must likewise be scaled down; but if outside, left unchanged.

addr = htlbpage_to_page(addr);
end = htlbpage_to_page(end);
floor = htlbpage_to_page(floor);
if (REGION_NUMBER(ceiling) == RGN_HPAGE)
ceiling = htlbpage_to_page(ceiling);

free_pgd_range(tlb, addr, end, floor, ceiling);

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-06-02 22:09    [W:0.078 / U:3.712 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site