Hello Michael,
On Fri, Dec 04, 2015 at 04:50:03PM +0100, Michael Kerrisk (man-pages) wrote:
> Hi Andrea,
>
> On 09/11/2015 10:47 AM, Michael Kerrisk (man-pages) wrote:
> > On 05/14/2015 07:30 PM, Andrea Arcangeli wrote:
> >> Add documentation.
> >
> > Hi And
handler for the tracked pages. The
> > performance result of kernel building is as followings:
> >
> >before after
> > real 461.63 real 455.48
> > user 4529.55 user 4557.88
> > sys 1995.39 sys 1922.57
>
> For KVM-GT, as far a
On Wed, Nov 11, 2015 at 08:47:34PM +0100, Christian Borntraeger wrote:
> Acked-by: Christian Borntraeger
> Who is going to take this patch? If I should take the patch, I need an
> ACK from the memory mgmt folks.
I would suggest to resend in CC to Andrew to merge in -mm after taking
care of the be
On Wed, Nov 11, 2015 at 09:01:44PM +0100, Christian Borntraeger wrote:
> Am 11.11.2015 um 18:30 schrieb Andrea Arcangeli:
> > Hi Jason,
> >
> > On Wed, Nov 11, 2015 at 10:35:16AM -0500, Jason J. Herne wrote:
> >> MADV_NOHUGEPAGE processing is too restrictive. kvm
On Thu, Oct 22, 2015 at 05:15:09PM +0200, Peter Zijlstra wrote:
> Indefinitely is such a long time, we should try and finish
> computation before the computer dies etc. :-)
Indefinitely as read_seqcount_retry, eventually it makes progress.
Even returning 0 from the page fault can trigger it again
On Thu, Oct 22, 2015 at 03:38:24PM +0200, Peter Zijlstra wrote:
> On Thu, Oct 22, 2015 at 03:20:15PM +0200, Andrea Arcangeli wrote:
>
> > If schedule spontaneously wakes up a task in TASK_KILLABLE state that
> > would be a bug in the scheduler in my view. Luckily there doesn
On Thu, Oct 22, 2015 at 02:10:56PM +0200, Peter Zijlstra wrote:
> On Thu, May 14, 2015 at 07:31:11PM +0200, Andrea Arcangeli wrote:
> > @@ -255,21 +259,23 @@ int handle_userfault(struct vm_area_struct *vma,
> > unsigned long address,
> >
Hello Patrick,
On Mon, Oct 12, 2015 at 11:04:11AM -0400, Patrick Donnelly wrote:
> Hello Andrea,
>
> On Mon, Jun 15, 2015 at 1:22 PM, Andrea Arcangeli wrote:
> > This is an incremental update to the userfaultfd code in -mm.
>
> Sorry I'm late to this party. I'
nclude
>
>
> -#define __NR_syscalls364
> +#define __NR_syscalls365
>
> #define __NR__exit __NR_exit
> #define NR_syscalls __NR_syscalls
Reviewed-by: Andrea Arcangeli
--
To unsubscribe from this list: send the line "unsubscribe kvm&q
Hi Dave,
On Tue, Jun 23, 2015 at 12:00:19PM -0700, Dave Hansen wrote:
> Down in userfaultfd_wake_function(), it looks like you intended for a
> len=0 to mean "wake all". But the validate_range() that we do from
> userspace has a !len check in it, which keeps us from passing a len=0 in
> from user
On Mon, Jun 15, 2015 at 08:41:24PM -1000, Linus Torvalds wrote:
> On Mon, Jun 15, 2015 at 12:19 PM, Andrea Arcangeli
> wrote:
> >
> > Yes, it would leave the other blocked, how is it different from having
> > just 1 reader and it gets killed?
>
> Either is complet
On Mon, Jun 15, 2015 at 08:19:07AM -1000, Linus Torvalds wrote:
> What if the process doing the polling never doors anything with the end
> result? Maybe it meant to, but it got killed before it could? Are you going
> to leave everybody else blocked, even though there are pending events?
Yes, it w
On Mon, Jun 15, 2015 at 08:11:50AM -1000, Linus Torvalds wrote:
> On Jun 15, 2015 7:22 AM, "Andrea Arcangeli" wrote:
> >
> > + if (cmd != UFFDIO_API) {
> > + if (ctx->state == UFFD_STATE_WAIT_API)
> > + return
635,219,658 branches # 256.660 M/sec
( +- 0.71% ) [83.69%]
59,203,898 branch-misses #0.51% of all branches
( +- 2.03% ) [83.54%]
2.600912438 seconds time elapsed
( +- 0.02% )
Signed
by userfaultfd. The fix for those two bugs was also
strightforward and required no design change of any sort.
Signed-off-by: Andrea Arcangeli
---
tools/testing/selftests/vm/Makefile | 4 +-
tools/testing/selftests/vm/userfaultfd.c | 669 +++
2 files changed
During the refile in userfaultfd_read both waitqueues could look empty
to the lockless wake_userfault(). Use a seqcount to prevent this false
negative that could leave an userfault blocked.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 26 --
1 file changed, 24
IGBUS failure because the wrong page was
being copied.
For various reasons this wasn't easily reproducible in the qemu
workload, but the strestest exposed the problem immediately.
Signed-off-by: Andrea Arcangeli
---
mm/huge_memory.c | 10 ++
1 file changed, 6 insertions(+), 4 deletion
(all but UFFDIO_API/struct
uffdio_api) with a bump of uffdio_api.api.
There's no actual plan or need to change the API or the ioctl, the
current API already should cover fine even the non cooperative usage,
but this is just for the longer term future just in case.
Signed-off-by: Andrea Arca
ce as wakeall, has wait->flags
WQ_FLAG_EXCLUSIVE set.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 8
include/linux/wait.h | 5 ++---
kernel/sched/wait.c | 7 +++
net/sunrpc/sched.c | 2 +-
4 files changed, 10 insertions(+), 12 deletions(-)
diff --git a/fs/userf
need to get signal processed, coredumps always
worked perfectly with userfaults, no matter if the userfault is triggered by
GUP a kernel copy_user or directly from userland.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 35 ---
1 file changed, 32 inse
r CPUs. CPU bugs in SIMD cannot be
ruled out either yet.
Andrea Arcangeli (7):
userfaultfd: require UFFDIO_API before other ioctls
userfaultfd: propagate the full address in THP faults
userfaultfd: allow signals to interrupt a userfault
userfaultfd: avoid missing wakeups during refile
he buildbot was shutdown recently? That
buildbot was very useful to detect for problems like this.
===
>From 2f0a48670dc515932dec8b983871ec35caeba553 Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli
Date: Sat, 23 May 2015 02:26:32 +0200
Subject: [PATCH] userfaultfd: update the uffd_msg structure to be the same on
32
On Fri, May 22, 2015 at 01:18:22PM -0700, Andrew Morton wrote:
> On Thu, 14 May 2015 19:31:19 +0200 Andrea Arcangeli
> wrote:
>
> > If the rwsem starves writers it wasn't strictly a bug but lockdep
> > doesn't like it and this avoids depending on lowlevel impleme
Hi Kirill,
On Thu, May 21, 2015 at 04:11:11PM +0300, Kirill Smelkov wrote:
> Sorry for maybe speaking up too late, but here is additional real
Not too late, in fact I don't think there's any change required for
this at this stage, but it'd be great if you could help me to review.
> Since arrays
This implements the uABI of UFFDIO_COPY and UFFDIO_ZEROPAGE.
Signed-off-by: Andrea Arcangeli
---
include/uapi/linux/userfaultfd.h | 42 +++-
1 file changed, 41 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux
rom userfault
thread
This patch removes the need of both UFFDIO_WAKE and of the associated
per-page tristate as well.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 81 +---
1 file changed, 66 insertions(+), 15 deletions(-)
diff --gi
These two flags gets set in vma->vm_flags to tell the VM common code
if the userfaultfd is armed and in which mode (only tracking missing
faults, only tracking wrprotect faults or both). If neither flags is
set it means the userfaultfd is not armed on the vma.
Signed-off-by: Andrea Arcang
This implements the uABI of UFFDIO_REMAP.
Notably one mode bitflag is also forwarded (and in turn known) by the
lowlevel remap_pages method.
Signed-off-by: Andrea Arcangeli
---
include/uapi/linux/userfaultfd.h | 27 ++-
1 file changed, 26 insertions(+), 1 deletion
tiny corner
case.
Signed-off-by: Andrea Arcangeli
---
mm/huge_memory.c | 6 --
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 5374132..8f1b6a5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2145,7 +2145,8 @@ static int __col
On Thu, Mar 05, 2015 at 09:39:48AM -0800, Linus Torvalds wrote:
> Is this really worth it? On real loads? That people are expected to use?
I fully agree that it's not worth merging upstream UFFDIO_REMAP until
(and if) a real world usage for it will showup. To further clarify:
would this not have b
This adds the vm_userfaultfd_ctx to the vm_area_struct.
Signed-off-by: Andrea Arcangeli
---
include/linux/mm_types.h | 11 +++
kernel/fork.c| 1 +
2 files changed, 12 insertions(+)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 199a03a..fbf21f5
Defines the uAPI of the userfaultfd, notably the ioctl numbers and protocol.
Signed-off-by: Andrea Arcangeli
---
Documentation/ioctl/ioctl-number.txt | 1 +
include/uapi/linux/userfaultfd.h | 81
2 files changed, 82 insertions(+)
create mode 100644
This allows to select the userfaultfd during configuration to build it.
Signed-off-by: Andrea Arcangeli
---
fs/Makefile | 1 +
init/Kconfig | 11 +++
2 files changed, 12 insertions(+)
diff --git a/fs/Makefile b/fs/Makefile
index a88ac48..ba8ab62 100644
--- a/fs/Makefile
+++ b/fs
MP. Especially if copying only a few pages at time, copying without
TLB flush is faster.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 51 +++
1 file changed, 51 insertions(+)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 6230f22
some anon_vma.
Signed-off-by: Andrea Arcangeli
---
include/linux/swap.h | 6 ++
mm/swapfile.c| 13 +
2 files changed, 19 insertions(+)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 4759491..9adda11 100644
--- a/include/linux/swap.h
+++ b/include/linux
as parameter so the "read|write"
kind of fault can be passed to userland.
Signed-off-by: Andrea Arcangeli
---
mm/huge_memory.c | 68 ++--
mm/memory.c | 16 +
2 files changed, 62 insertions(+), 22 deletions(-)
di
before or
while remap_pages runs.
Signed-off-by: Andrea Arcangeli
---
mm/huge_memory.c | 23 +++
mm/rmap.c| 9 +
2 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8f1b6a5..1e25cb3 100644
--- a/mm/hug
These helpers will be used to know if to call handle_userfault() during
wrprotect faults in order to deliver the wrprotect faults to userland.
Signed-off-by: Andrea Arcangeli
---
include/linux/userfaultfd_k.h | 10 ++
1 file changed, 10 insertions(+)
diff --git a/include/linux
These two flags gets set in vma->vm_flags to tell the VM common code
if the userfaultfd is armed and in which mode (only tracking missing
faults, only tracking wrprotect faults or both). If neither flags is
set it means the userfaultfd is not armed on the vma.
Signed-off-by: Andrea Arcang
vma->vm_userfaultfd_ctx is yet another vma parameter that vma_merge
must be aware about so that we can merge vmas back like they were
originally before arming the userfaultfd on some memory range.
Signed-off-by: Andrea Arcangeli
---
include/linux/mm.h | 2 +-
mm/madvise.c | 3 ++-
This implements the uABI of UFFDIO_COPY and UFFDIO_ZEROPAGE.
Signed-off-by: Andrea Arcangeli
---
include/uapi/linux/userfaultfd.h | 46 +++-
1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux
a fully backwards
compatible change and it's only strictly required by the wrprotect
tracking mode, so it's no problem to solve this later. Because of its
inherent racy nature, nobody could possibly depend on a racy SIGBUS
being raised now, when it won't be raised anymore later.
Andre
Add documentation.
Signed-off-by: Andrea Arcangeli
---
Documentation/vm/userfaultfd.txt | 97
1 file changed, 97 insertions(+)
create mode 100644 Documentation/vm/userfaultfd.txt
diff --git a/Documentation/vm/userfaultfd.txt b/Documentation/vm
to know when there are new pending userfaults to be
read (POLLIN).
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 977 +++
1 file changed, 977 insertions(+)
create mode 100644 fs/userfaultfd.c
diff --git a/fs/userfaultfd.c b/fs
remap_pages is the lowlevel mm helper needed to implement
UFFDIO_REMAP.
Signed-off-by: Andrea Arcangeli
---
include/linux/userfaultfd_k.h | 17 ++
mm/huge_memory.c | 120 ++
mm/userfaultfd.c | 526 ++
3 files changed
userfaultfd needs to wake all waitqueues (pass 0 as nr parameter),
instead of the current hardcoded 1 (that would wake just the first
waitqueue in the head list).
Signed-off-by: Andrea Arcangeli
---
include/linux/wait.h | 5 +++--
kernel/sched/wait.c | 7 ---
net/sunrpc/sched.c | 2 +-
3
Kernel header defining the methods needed by the VM common code to
interact with the userfaultfd.
Signed-off-by: Andrea Arcangeli
---
include/linux/userfaultfd_k.h | 79 +++
1 file changed, 79 insertions(+)
create mode 100644 include/linux
This activates the userfaultfd syscall.
Signed-off-by: Andrea Arcangeli
---
arch/powerpc/include/asm/systbl.h | 1 +
arch/powerpc/include/asm/unistd.h | 2 +-
arch/powerpc/include/uapi/asm/unistd.h | 1 +
arch/x86/syscalls/syscall_32.tbl | 1 +
arch/x86/syscalls/syscall_64.tbl
This implements mcopy_atomic and mfill_zeropage that are the lowlevel
VM methods that are invoked respectively by the UFFDIO_COPY and
UFFDIO_ZEROPAGE userfaultfd commands.
Signed-off-by: Andrea Arcangeli
---
include/linux/userfaultfd_k.h | 6 +
mm/Makefile | 1 +
mm
These two ioctl allows to either atomically copy or to map zeropages
into the virtual address space. This is used by the thread that opened
the userfaultfd to resolve the userfaults.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 100
On Thu, Jan 08, 2015 at 11:59:06AM +, Marc Zyngier wrote:
> From: Steve Capper
>
> ptep_clear_flush_young_notify and pmdp_clear_flush_young_notify both
> call the notifiers *after* the pte/pmd has been made young.
>
On x86 on EPT without hardware access bit (!shadow_accessed_mask),
we'll tr
On Fri, Nov 21, 2014 at 11:05:45PM +, Peter Maydell wrote:
> If it's mapped and readable-but-not-writable then it should still
> fault on write accesses, though? These are cases we currently get
> SEGV for, anyway.
Yes then it'll work just fine.
> Ah, I guess we have a terminology difference.
Hi Peter,
On Wed, Oct 29, 2014 at 05:56:59PM +, Peter Maydell wrote:
> On 29 October 2014 17:46, Andrea Arcangeli wrote:
> > After some chat during the KVMForum I've been already thinking it
> > could be beneficial for some usage to give userland the information
>
Hi,
On Thu, Nov 20, 2014 at 10:54:29AM +0800, zhanghailiang wrote:
> Yes, you are right. This is what i really want, bypass all non-present faults
> and only track strict wrprotect faults. ;)
>
> So, do you plan to support that in the userfault API?
Yes I think it's good idea to support wrprotec
Hi,
On Fri, Oct 31, 2014 at 12:39:32PM -0700, Peter Feiner wrote:
> On Fri, Oct 31, 2014 at 11:29:49AM +0800, zhanghailiang wrote:
> > Agreed, but for doing live memory snapshot (VM is running when do
> > snapsphot),
> > we have to do this (block the write action), because we have to save the
>
Hi Zhang,
On Fri, Oct 31, 2014 at 09:26:09AM +0800, zhanghailiang wrote:
> On 2014/10/30 20:49, Dr. David Alan Gilbert wrote:
> > * zhanghailiang (zhang.zhanghaili...@huawei.com) wrote:
> >> On 2014/10/30 1:46, Andrea Arcangeli wrote:
> >>> Hi Zhanghailiang,
> >
Hi Zhanghailiang,
On Mon, Oct 27, 2014 at 05:32:51PM +0800, zhanghailiang wrote:
> Hi Andrea,
>
> Thanks for your hard work on userfault;)
>
> This is really a useful API.
>
> I want to confirm a question:
> Can we support distinguishing between writing and reading memory for
> userfault?
> Th
On Thu, Oct 09, 2014 at 12:50:37PM +0200, Peter Zijlstra wrote:
> On Wed, Oct 01, 2014 at 10:56:35AM +0200, Andrea Arcangeli wrote:
>
> > +static inline long __get_user_pages_locked(struct task_struct *tsk,
> > + st
On Thu, Oct 09, 2014 at 12:47:23PM +0200, Peter Zijlstra wrote:
> On Wed, Oct 01, 2014 at 10:56:35AM +0200, Andrea Arcangeli wrote:
> > +static inline long __get_user_pages_locked(struct task_struct *tsk,
> > + struc
On Thu, Oct 09, 2014 at 12:52:45PM +0200, Peter Zijlstra wrote:
> On Wed, Oct 01, 2014 at 10:56:36AM +0200, Andrea Arcangeli wrote:
> > Just an optimization.
>
> Does it make sense to split the thing in two? One where you apply
> _unlocked and then one where you apply _fast?
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
> c
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 wrote:
> >
> > Of course if somebody has better ideas on how to resolve an anonymous
> > userfault they're welcome.
>
> So I'd
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
Hi Kirill,
On Tue, Oct 07, 2014 at 01:36:45PM +0300, Kirill A. Shutemov wrote:
> On Fri, Oct 03, 2014 at 07:07:58PM +0200, Andrea Arcangeli wrote:
> > MADV_USERFAULT is a new madvise flag that will set VM_USERFAULT in the
> > vma flags. Whenever VM_USERFAULT is set in an an
Hi,
On Sat, Oct 04, 2014 at 08:13:36AM +0900, Mike Hommey wrote:
> On Fri, Oct 03, 2014 at 07:07:58PM +0200, Andrea Arcangeli wrote:
> > MADV_USERFAULT is a new madvise flag that will set VM_USERFAULT in the
> > vma flags. Whenever VM_USERFAULT is set in an anonymous vma, if
>
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
> > wrote:
> > >
> > > Overall this looks a fairly small change to
Hello,
On Fri, Oct 03, 2014 at 11:23:53AM -0700, Linus Torvalds wrote:
> On Fri, Oct 3, 2014 at 10:07 AM, Andrea Arcangeli wrote:
> > This teaches gup_fast and __gup_fast to re-enable irqs and
> > cond_resched() if possible every BATCH_PAGES.
>
> This is disgusting.
>
&
exclusive if set.
Signed-off-by: Andrea Arcangeli
---
arch/alpha/include/uapi/asm/mman.h | 3 ++
arch/mips/include/uapi/asm/mman.h | 3 ++
arch/parisc/include/uapi/asm/mman.h| 3 ++
arch/xtensa/include/uapi/asm/mman.h| 3 ++
fs/proc/task_mmu.c | 1
er process that is calling
ptrace). We could also decide to retain the current -EFAULT behavior
of ptrace using get_user_pages_locked with a NULL locked parameter so
the FAULT_FLAG_ALLOW_RETRY flag will not be set. Either ways would be
safe.
Signed-off-by: Andrea Arcangeli
---
write MADV_USERFAULT */
c[i+1] = 0xbb;
}
if (c[i] != 0xaa)
printf("error %x offset %lu\n", c[i], i), exit(1);
}
printf("remap_anon_pages functions correctly\n");
return 0;
}
===
Signe
ent->mm. get_user_pages_unlocked varies from
get_user_pages_fast only if mm is not current->mm (like when
get_user_pages works on some other process mm). Whenever tsk and mm
matches current and current->mm get_user_pages_fast must always be
used to increase performance and get the page loc
Just an optimization.
Signed-off-by: Andrea Arcangeli
---
drivers/dma/iovlock.c | 10 ++
drivers/iommu/amd_iommu_v2.c | 6 ++
drivers/media/pci/ivtv/ivtv-udma.c | 6 ++
drivers/scsi/st.c | 10 ++
drivers/video/fbdev/pvr2fb.c
p_anon_pages runs.
Signed-off-by: Andrea Arcangeli
---
mm/huge_memory.c | 24
mm/rmap.c| 9 +
2 files changed, 29 insertions(+), 4 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b402d60..4277ed7 100644
--- a/mm/huge_memory.c
+++ b/mm
We run out of 32bits in vm_flags, noop change for 64bit archs.
Signed-off-by: Andrea Arcangeli
---
fs/proc/task_mmu.c | 4 ++--
include/linux/huge_mm.h | 4 ++--
include/linux/ksm.h | 4 ++--
include/linux/mm_types.h | 2 +-
mm/huge_memory.c | 2 +-
mm/ksm.c
Those two helpers are needed by remap_anon_pages.
Signed-off-by: Andrea Arcangeli
---
include/linux/mm.h | 4
mm/fremap.c| 29 +
2 files changed, 33 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index bf3df07..71dbe03 100644
--- a
ges
should do it fine too, but it would create rmap nonlinearity which
isn't optimal.
The code can be found here:
git clone --reference linux
git://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git -b userfault
The branch is rebased so you can get updates for example with:
git fetch &am
, as other mmap semaphore users
now stall as a function of swap or filemap latency.
This patch ensures both the regular and async PF path re-enter the
fault allowing for the mmap semaphore to be relinquished in the case
of IO wait.
Reviewed-by: Radim Krčmář
Signed-off-by: Andres Lagar-Cavilla
Signed
using get_user_pages_unlocked which would be
slower).
Signed-off-by: Andrea Arcangeli
---
arch/x86/mm/gup.c | 234 ++
1 file changed, 149 insertions(+), 85 deletions(-)
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c
index 2ab183b..917d8c1 100644
--- a/arch/x
userfaults to read (POLLIN) and when there
are threads waiting a wakeup through a range write (POLLOUT).
Signed-off-by: Andrea Arcangeli
---
arch/x86/syscalls/syscall_32.tbl | 1 +
arch/x86/syscalls/syscall_64.tbl | 1 +
fs/Makefile | 1 +
fs/userfaultfd.c
From: Andres Lagar-Cavilla
Reviewed-by: Radim Krčmář
Signed-off-by: Andres Lagar-Cavilla
Signed-off-by: Andrea Arcangeli
---
include/linux/mm.h | 1 +
mm/gup.c | 4
2 files changed, 5 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8981cc8..0f4196a
same address. But we should still
return an error so if the application thinks this occurrence can never
happen it will know it hit a bug. So just return -ENOENT instead of
blocking.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 34 +-
1 file changed, 5 inser
Signed-off-by: Andrea Arcangeli
---
arch/mips/mm/gup.c | 8 +++-
arch/powerpc/mm/gup.c| 6 ++
arch/s390/kvm/kvm-s390.c | 4 +---
arch/s390/mm/gup.c | 6 ++
arch/sh/mm/gup.c | 6 ++
arch/sparc/mm/gup.c | 6 ++
arch/x86/mm/gup.c| 7
Add the syscall numbers.
Signed-off-by: Andrea Arcangeli
---
arch/powerpc/include/asm/systbl.h | 2 ++
arch/powerpc/include/asm/unistd.h | 2 +-
arch/powerpc/include/uapi/asm/unistd.h | 2 ++
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm
Userfaultfd needs to wake all waitqueues (pass 0 as nr parameter),
instead of the current hardcoded 1 (that would wake just the first
waitqueue in the head list).
Signed-off-by: Andrea Arcangeli
---
include/linux/wait.h | 5 +++--
kernel/sched/wait.c | 7 ---
net/sunrpc/sched.c | 2 +-
3
in some anon_vma.
Signed-off-by: Andrea Arcangeli
---
include/linux/swap.h | 6 ++
mm/swapfile.c| 13 +
2 files changed, 19 insertions(+)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 8197452..af9977c 100644
--- a/include/linux/swap.h
+++ b/include/linux
On Thu, Oct 02, 2014 at 02:56:38PM +0200, Peter Zijlstra wrote:
> On Thu, Oct 02, 2014 at 02:50:52PM +0200, Peter Zijlstra wrote:
> > On Thu, Oct 02, 2014 at 02:31:17PM +0200, Andrea Arcangeli wrote:
> > > On Wed, Oct 01, 2014 at 05:36:11PM +0200, Peter Zijlstra wrote:
> &g
On Wed, Oct 01, 2014 at 10:06:27AM -0700, Andres Lagar-Cavilla wrote:
> On Wed, Oct 1, 2014 at 8:51 AM, Peter Feiner wrote:
> > On Wed, Oct 01, 2014 at 10:56:35AM +0200, Andrea Arcangeli wrote:
> >> + /* VM_FAULT_RETRY cannot return errors */
> >>
On Wed, Oct 01, 2014 at 05:36:11PM +0200, Peter Zijlstra wrote:
> For all these and the other _fast() users, is there an actual limit to
> the nr_pages passed in? Because we used to have the 64 pages limit from
> DIO, but without that we get rather long IRQ-off latencies.
Ok, I would tend to think
On Wed, Oct 01, 2014 at 10:56:36AM +0200, Andrea Arcangeli wrote:
> diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
> index f74fc0c..cd20669 100644
> --- a/drivers/misc/sgi-gru/grufault.c
> +++ b/drivers/misc/sgi-gru/grufault.c
> @@ -198,8 +198,
Just an optimization.
Signed-off-by: Andrea Arcangeli
---
drivers/dma/iovlock.c | 10 ++
drivers/iommu/amd_iommu_v2.c | 6 ++
drivers/media/pci/ivtv/ivtv-udma.c | 6 ++
drivers/misc/sgi-gru/grufault.c| 3 +--
drivers/scsi/st.c | 10
Signed-off-by: Andrea Arcangeli
---
arch/mips/mm/gup.c | 8 +++-
arch/powerpc/mm/gup.c| 6 ++
arch/s390/kvm/kvm-s390.c | 4 +---
arch/s390/mm/gup.c | 6 ++
arch/sh/mm/gup.c | 6 ++
arch/sparc/mm/gup.c | 6 ++
arch/x86/mm/gup.c| 7
serfaultfd backed memory.
Reviews would be welcome, thanks,
Andrea
Andrea Arcangeli (3):
mm: gup: add get_user_pages_locked and get_user_pages_unlocked
mm: gup: use get_user_pages_fast and get_user_pages_unlocked
mm: gup: use get_user_pages_unlocked within get_user_pages_fast
Andres Laga
From: Andres Lagar-Cavilla
Reviewed-by: Radim Krčmář
Signed-off-by: Andres Lagar-Cavilla
Signed-off-by: Andrea Arcangeli
---
include/linux/mm.h | 1 +
mm/gup.c | 4
2 files changed, 5 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8981cc8..0f4196a
ent->mm. get_user_pages_unlocked varies from
get_user_pages_fast only if mm is not current->mm (like when
get_user_pages works on some other process mm). Whenever tsk and mm
matches current and current->mm get_user_pages_fast must always be
used to increase performance and get the page
On Fri, Sep 26, 2014 at 12:54:46PM -0700, Andres Lagar-Cavilla wrote:
> On Fri, Sep 26, 2014 at 10:25 AM, Andrea Arcangeli
> wrote:
> > On Thu, Sep 25, 2014 at 02:50:29PM -0700, Andres Lagar-Cavilla wrote:
> >> It's nearly impossible to name it right beca
ocked parameter) will not invoke the
userfaultfd protocol.
But I need gup_fast to use FAULT_FLAG_ALLOW_RETRY because core places
like O_DIRECT uses it.
I tried to do a RFC patch below that goes into this direction and
should be enough for a start to solve all my issues with the mmap_sem
holding
On Thu, Sep 25, 2014 at 03:26:50PM -0700, Andres Lagar-Cavilla wrote:
> Confusion around -EBUSY and zero (inside a BUG_ON no less).
>
> Reported-by: AndreA Arcangeli
> Signed-off-by: Andres Lagar-Cavilla
> ---
> virt/kvm/kvm_main.c | 2 +-
> 1 file changed, 1 ins
Hi Andres,
On Wed, Sep 17, 2014 at 10:51:48AM -0700, Andres Lagar-Cavilla wrote:
> + if (!locked) {
> + VM_BUG_ON(npages != -EBUSY);
> +
Shouldn't this be VM_BUG_ON(npages)?
Alternatively we could patch gup to do:
case -EHWPOISON:
+
Hi Andy,
thanks for CC'ing linux-api.
On Wed, Jul 02, 2014 at 06:56:03PM -0700, Andy Lutomirski wrote:
> On 07/02/2014 09:50 AM, Andrea Arcangeli wrote:
> > Once an userfaultfd is created MADV_USERFAULT regions talks through
> > the userfaultfd protocol with the thread respo
On Mon, Apr 28, 2014 at 01:06:05PM +0200, Paolo Bonzini wrote:
> Patch 1 will be for 3.16 only, I'd like a review from Marcelo or Andrea
> though (that's "KVM: async_pf: kill the unnecessary use_mm/unuse_mm
> async_pf_execute()" for easier googling).
Patch 1:
Revi
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