On Fri, Oct 03, 2014 at 07:08:00PM +0200, Andrea Arcangeli wrote:
There's one constraint enforced to allow this simplification: the
source pages passed to remap_anon_pages must be mapped only in one
vma, but this is not a limitation when used to handle userland page
faults with MADV_USERFAULT.
On Mon, Oct 6, 2014 at 12:41 PM, Andrea Arcangeli aarca...@redhat.com wrote:
Of course if somebody has better ideas on how to resolve an anonymous
userfault they're welcome.
So I'd *much* rather have a write() style interface (ie _copying_
bytes from user space into a newly allocated page that
Hi Kirill,
On Tue, Oct 07, 2014 at 02:10:26PM +0300, Kirill A. Shutemov wrote:
On Fri, Oct 03, 2014 at 07:08:00PM +0200, Andrea Arcangeli wrote:
There's one constraint enforced to allow this simplification: the
source pages passed to remap_anon_pages must be mapped only in one
vma, but
Hello,
On Tue, Oct 07, 2014 at 08:47:59AM -0400, Linus Torvalds wrote:
On Mon, Oct 6, 2014 at 12:41 PM, Andrea Arcangeli aarca...@redhat.com wrote:
Of course if somebody has better ideas on how to resolve an anonymous
userfault they're welcome.
So I'd *much* rather have a write() style
On Tue, Oct 07, 2014 at 04:19:13PM +0200, Andrea Arcangeli wrote:
mremap like interface, or file+commands protocol interface. I tend to
like mremap more, that's why I opted for a remap_anon_pages syscall
kept orthogonal to the userfaultfd functionality (remap_anon_pages
could be also used
On Tue, Oct 7, 2014 at 8:52 AM, Andrea Arcangeli aarca...@redhat.com wrote:
On Tue, Oct 07, 2014 at 04:19:13PM +0200, Andrea Arcangeli wrote:
mremap like interface, or file+commands protocol interface. I tend to
like mremap more, that's why I opted for a remap_anon_pages syscall
kept
On Tue, Oct 07, 2014 at 05:52:47PM +0200, Andrea Arcangeli wrote:
I probably grossly overestimated the benefits of resolving the
userfault with a zerocopy page move, sorry. [...]
For posterity, I think it's worth noting that most expensive aspect of a TLB
shootdown is the interprocessor
On Tue, Oct 7, 2014 at 10:19 AM, Andrea Arcangeli aarca...@redhat.com wrote:
I see what you mean. The only cons I see is that we couldn't use then
recv(tmp_addr, PAGE_SIZE), remap_anon_pages(faultaddr, tmp_addr,
PAGE_SIZE, ..) and retain the zerocopy behavior. Or how could we?
There's no
Il 07/10/2014 19:07, Dr. David Alan Gilbert ha scritto:
So I'd *much* rather have a write() style interface (ie _copying_
bytes from user space into a newly allocated page that gets mapped)
than a remap page style interface
Something like that might work for the postcopy case; it doesn't
* Paolo Bonzini (pbonz...@redhat.com) wrote:
Il 07/10/2014 19:07, Dr. David Alan Gilbert ha scritto:
So I'd *much* rather have a write() style interface (ie _copying_
bytes from user space into a newly allocated page that gets mapped)
than a remap page style interface
Something
* Linus Torvalds (torva...@linux-foundation.org) wrote:
On Mon, Oct 6, 2014 at 12:41 PM, Andrea Arcangeli aarca...@redhat.com wrote:
Of course if somebody has better ideas on how to resolve an anonymous
userfault they're welcome.
So I'd *much* rather have a write() style interface (ie
* Linus Torvalds (torva...@linux-foundation.org) wrote:
On Fri, Oct 3, 2014 at 10:08 AM, Andrea Arcangeli aarca...@redhat.com wrote:
Overall this looks a fairly small change to the rmap code, notably
less intrusive than the nonlinear vmas created by remap_file_pages.
Considering that
Hello,
On Mon, Oct 06, 2014 at 09:55:41AM +0100, Dr. David Alan Gilbert wrote:
* Linus Torvalds (torva...@linux-foundation.org) wrote:
On Fri, Oct 3, 2014 at 10:08 AM, Andrea Arcangeli aarca...@redhat.com
wrote:
Overall this looks a fairly small change to the rmap code, notably
remap_anon_pages (unlike remap_file_pages) tries to be non intrusive
in the rmap code.
As far as the rmap code is concerned, rmap_anon_pages only alters the
page-mapping and page-index. It does it while holding the page
lock. However there are a few places that in presence of anon pages
are
On Fri, Oct 3, 2014 at 10:08 AM, Andrea Arcangeli aarca...@redhat.com wrote:
Overall this looks a fairly small change to the rmap code, notably
less intrusive than the nonlinear vmas created by remap_file_pages.
Considering that remap_file_pages() was an unmitigated disaster, and
-mm has a
15 matches
Mail list logo
