Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1281211 > unrolled thread
| Started by | Dave Hansen <dave.hansen@intel.com> |
|---|---|
| First post | 2015-12-01 22:00 +0100 |
| Last post | 2015-12-01 22:10 +0100 |
| Articles | 2 — 2 participants |
Back to article view | Back to linux.kernel
This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by
below is the oldest one visible, not the original post.
Re: [PATCH 3/9] mm: postpone page table allocation until do_set_pte() Dave Hansen <dave.hansen@intel.com> - 2015-12-01 22:00 +0100
Re: [PATCH 3/9] mm: postpone page table allocation until do_set_pte() "Kirill A. Shutemov" <kirill@shutemov.name> - 2015-12-01 22:10 +0100
| From | Dave Hansen <dave.hansen@intel.com> |
|---|---|
| Date | 2015-12-01 22:00 +0100 |
| Subject | Re: [PATCH 3/9] mm: postpone page table allocation until do_set_pte() |
| Message-ID | <qB0bL-6as-9@gated-at.bofh.it> |
On 11/18/2015 03:25 PM, Kirill A. Shutemov wrote:
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2068,11 +2068,6 @@ void filemap_map_pages(struct fault_env *fe,
...
> if (file->f_ra.mmap_miss > 0)
> file->f_ra.mmap_miss--;
> - do_set_pte(fe, page);
> +
> + fe->address += (iter.index - last_pgoff) << PAGE_SHIFT;
> + if (fe->pte)
> + fe->pte += iter.index - last_pgoff;
> + last_pgoff = iter.index;
> + if (do_set_pte(fe, NULL, page)) {
> + /* failed to setup page table: giving up */
> + if (!fe->pte)
> + break;
> + goto unlock;
> + }
> unlock_page(page);
> goto next;
Hey Kirill,
Is there a case here where do_set_pte() returns an error and _still_
manages to populate fe->pte?
--
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/
[toc] | [next] | [standalone]
| From | "Kirill A. Shutemov" <kirill@shutemov.name> |
|---|---|
| Date | 2015-12-01 22:10 +0100 |
| Message-ID | <qB0ls-6t4-11@gated-at.bofh.it> |
| In reply to | #1281211 |
On Tue, Dec 01, 2015 at 12:53:25PM -0800, Dave Hansen wrote:
> On 11/18/2015 03:25 PM, Kirill A. Shutemov wrote:
> > --- a/mm/filemap.c
> > +++ b/mm/filemap.c
> > @@ -2068,11 +2068,6 @@ void filemap_map_pages(struct fault_env *fe,
> ...
> > if (file->f_ra.mmap_miss > 0)
> > file->f_ra.mmap_miss--;
> > - do_set_pte(fe, page);
> > +
> > + fe->address += (iter.index - last_pgoff) << PAGE_SHIFT;
> > + if (fe->pte)
> > + fe->pte += iter.index - last_pgoff;
> > + last_pgoff = iter.index;
> > + if (do_set_pte(fe, NULL, page)) {
> > + /* failed to setup page table: giving up */
> > + if (!fe->pte)
> > + break;
> > + goto unlock;
> > + }
> > unlock_page(page);
> > goto next;
>
> Hey Kirill,
>
> Is there a case here where do_set_pte() returns an error and _still_
> manages to populate fe->pte?
Yes. If the page is already mapped, we will get VM_FAULT_NOPAGE:
do_set_pte()
pte_alloc_one_map()
!pmd_none(*fe->pmd) => goto map_pte;
fe->pte = pte_offset_map_lock()
!pte_none(*fe->pte) => return VM_FAULT_NOPAGE;
--
Kirill A. Shutemov
--
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/
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web