Initial Post (Thu, 18 Aug 2005)
In preparation for hugetlb demand faulting, remove this get_user_pages()
optimization. Since huge pages will no longer be prefaulted, we can't assume
that the huge ptes are established and hence, calling follow_hugetlb_page() is
not valid.
With the follow_hugetlb_page() call removed, the normal code path will be
triggered. follow_page() will either use follow_huge_addr() or
follow_huge_pmd() to check for a previously faulted "page" to return. When
this fails (ie. with demand faults), __handle_mm_fault() gets called which
invokes the hugetlb_fault() handler to instantiate the huge page.
This patch doesn't make a lot of sense by itself, but I've broken it out to
facilitate discussion on this specific element of the demand fault changes.
While coding this up, I referenced previous discussion on this topic starting
at http://lkml.org/lkml/2004/4/13/176 , which contains more opinions about the
correctness of this approach.
Diffed against 2.6.14-rc2-git6
Signed-off-by: Adam Litke <[email protected]>
---
memory.c | 5 -----
1 files changed, 5 deletions(-)
diff -upN reference/mm/memory.c current/mm/memory.c
--- reference/mm/memory.c
+++ current/mm/memory.c
@@ -949,11 +949,6 @@ int get_user_pages(struct task_struct *t
|| !(flags & vma->vm_flags))
return i ? : -EFAULT;
- if (is_vm_hugetlb_page(vma)) {
- i = follow_hugetlb_page(mm, vma, pages, vmas,
- &start, &len, i);
- continue;
- }
spin_lock(&mm->page_table_lock);
do {
int write_access = write;
--
Adam Litke - (agl at us.ibm.com)
IBM Linux Technology Center
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
| |
 |