On Wed, Jul 25, 2018 at 08:17:37PM +0100, Dr. David Alan Gilbert wrote:
> * Peter Xu (pet...@redhat.com) wrote:
> > On Fri, Jun 29, 2018 at 12:53:59PM +0100, Dr. David Alan Gilbert wrote:
> > > * Denis Plotnikov (dplotni...@virtuozzo.com) wrote:
> > > > The patch set adds the ability to make extern
Hello,
On Mon, Jul 02, 2018 at 09:52:08PM +0800, Peng Tao wrote:
> I think we can write some host generated random seeds to guest's
> urandom device, when cloning VMs from the same template before handing
> it to users. Is it enough or do you think there are more to do w/
> re-randomizing?
That m
Hello everyone,
On Mon, Jul 02, 2018 at 02:10:54PM +0100, Stefan Hajnoczi wrote:
> Marcelo, Andrea, Paolo: There was a more complex local migration
> approach in 2013 with fd passing and vmsplice. They specifically
> avoided the approach proposed in this patch, but I don't remember why.
>
> The
pointer is
not NULL) or we need to revert part of commit
ce53053ce378c21e7ffc45241fd67d6ee79daa2b and keep using FOLL_NOWAIT
only as parameter to get_user_pages (which won't ever set nonblocking
pointer to non-NULL). I suppose the former approach is preferred to be
more robust.
Thanks,
Andrea
A
cause of
FOLL_NOWAIT.
Reported-by: Dr. David Alan Gilbert
Tested-by: Dr. David Alan Gilbert
Signed-off-by: Andrea Arcangeli
---
mm/gup.c | 7 +--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index 1b46e6e74881..6afae32571ca 100644
--- a/mm/gup.c
+++
On Tue, Jul 11, 2017 at 12:22:32PM +0800, Peter Xu wrote:
> On Wed, Jun 28, 2017 at 08:00:40PM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert"
> >
> > Cause the vhost-user client to be woken up whenever:
> > a) We place a page in postcopy mode
>
> Just to make sur
On Thu, Apr 27, 2017 at 08:44:03AM +0200, Christian Borntraeger wrote:
> I have started instrumenting the kernel. I can see a set_pte_at for this
> address
> and I see an (to be understood) invalidation shortly after that which explains
> why I get a fault.
Sounds great that you can see an invali
Hello,
On Wed, Apr 26, 2017 at 08:04:43PM +0100, Dr. David Alan Gilbert wrote:
> * Christian Borntraeger (borntrae...@de.ibm.com) wrote:
> > On 04/26/2017 08:37 PM, Dr. David Alan Gilbert (git) wrote:
> > > From: "Dr. David Alan Gilbert"
> > >
> > > When an all-zero page is received during the p
Hello,
On Wed, Mar 08, 2017 at 05:30:55PM -0800, Mike Kravetz wrote:
> On 01/10/2017 03:02 PM, Mike Kravetz wrote:
> > Another more concrete topic is hugetlb reservations. Michal Hocko
> > proposed the topic "mm patches review bandwidth", and brought up the
> > related subject of areas in need of
Hello,
On Mon, Mar 13, 2017 at 10:53:39AM +, Dr. David Alan Gilbert wrote:
> * Alexey Perevalov (a.pereva...@samsung.com) wrote:
> > Hi, David, Andrea and Mike
>
> Hi Alexey,
>
> > The problem I want to discuss it's 1G hugepage based VM and post copy live
> > migration.
> >
> > I would like
it to memset for a
> single byte write.
>
> Signed-off-by: Daniel P. Berrange
> ---
>
> Changed in v3:
Reviewed-by: Andrea Arcangeli
Thanks,
Andrea
Hello,
On Tue, Feb 28, 2017 at 09:48:26AM +0800, Hailiang Zhang wrote:
> Yes, for current implementing of live snapshot, it supports tcg,
> but does not support kvm mode, the reason i have mentioned above,
> if you try to implement it, i think you need to start from userfaultfd
> supporting KVM. T
Hello,
On Fri, Feb 24, 2017 at 05:27:14PM +, Daniel P. Berrange wrote:
> diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> index 35012b9..2a5bb93 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -355,7 +355,20 @@ void os_mem_prealloc(int fd, char *area, size_t memory,
>
Hello,
On Mon, Feb 27, 2017 at 11:26:58AM +, Dr. David Alan Gilbert wrote:
> * Alexey Perevalov (a.pereva...@samsung.com) wrote:
> > Also if I'm not wrong, commands and pages are transferred over the same
> > socket. Why not to use OOB TCP in this case for commands?
>
> My understanding was t
Hello Alexey,
On Tue, Feb 14, 2017 at 05:48:25PM +0300, Alexey Perevalov wrote:
> On Mon, Feb 13, 2017 at 06:57:22PM +0100, Andrea Arcangeli wrote:
> > Hello,
> >
> > On Mon, Feb 13, 2017 at 08:11:06PM +0300, Alexey Perevalov wrote:
> > > Another one request.
&g
On Mon, Feb 13, 2017 at 06:57:22PM +0100, Andrea Arcangeli wrote:
> Hello,
>
> On Mon, Feb 13, 2017 at 08:11:06PM +0300, Alexey Perevalov wrote:
> > Another one request.
> > QEMU could use mem_path in hugefs with share key simultaneously
> > (-object
> >
Hello,
On Mon, Feb 13, 2017 at 08:11:06PM +0300, Alexey Perevalov wrote:
> Another one request.
> QEMU could use mem_path in hugefs with share key simultaneously
> (-object
> memory-backend-file,id=mem,size=${mem_size},mem-path=${mem_path},share=on)
> and vm
> in this case will start and will pr
not fundamental for correct functionality of the
guest pv spinlock code.
This bug was introduced in commit
0b9f6c4615c993d2b552e0d2bd1ade49b56e5beb in v4.9-rc7.
>From 458897fd44aa9b91459a006caa4051a7d1628a23 Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli
Date: Sat, 17 Dec 2016 18:43:52 +0100
Subject: [PATCH 1/2
On Thu, Dec 15, 2016 at 05:40:45PM -0800, Dave Hansen wrote:
> On 12/15/2016 05:38 PM, Li, Liang Z wrote:
> >
> > Use 52 bits for 'pfn', 12 bits for 'length', when the 12 bits is not long
> > enough for the 'length'
> > Set the 'length' to a special value to indicate the "actual length in next
>
On Fri, Dec 16, 2016 at 01:12:21AM +, Li, Liang Z wrote:
> There still exist the case if the MAX_ORDER is configured to a large value,
> e.g. 36 for a system
> with huge amount of memory, then there is only 28 bits left for the pfn,
> which is not enough.
Not related to the balloon but how w
Hello,
On Fri, Dec 09, 2016 at 05:35:45AM +, Li, Liang Z wrote:
> > On 12/08/2016 08:45 PM, Li, Liang Z wrote:
> > > What's the conclusion of your discussion? It seems you want some
> > > statistic before deciding whether to ripping the bitmap from the ABI,
> > > am I right?
> >
> > I think
On Wed, Dec 07, 2016 at 11:54:34AM -0800, Dave Hansen wrote:
> We're talking about a bunch of different stuff which is all being
> conflated. There are 3 issues here that I can see. I'll attempt to
> summarize what I think is going on:
>
> 1. Current patches do a hypercall for each order in the
On Wed, Dec 07, 2016 at 10:44:31AM -0800, Dave Hansen wrote:
> On 12/07/2016 10:38 AM, Andrea Arcangeli wrote:
> >> > and leaves room for the bitmap size to be encoded as well, if we decide
> >> > we need a bitmap in the future.
> > How would a bitmap ever be
Hello,
On Wed, Dec 07, 2016 at 08:57:01AM -0800, Dave Hansen wrote:
> It is more space-efficient. We're fitting the order into 6 bits, which
> would allows the full 2^64 address space to be represented in one entry,
Very large order is the same as very large len, 6 bits of order or 8
bytes of le
Hello,
On Thu, Oct 13, 2016 at 09:30:49AM +0100, Dr. David Alan Gilbert wrote:
> I think it should, or at least I think all other kernel things end up being
> caught by userfaultfd during postcopy.
Yes indeed, it will work. vhost blocks in its own task context inside
the kernel and the vmsave/pos
Hello everyone,
I've an aa.git tree uptodate on the master & userfault branch (master
includes other pending VM stuff, userfault branch only contains
userfault enhancements):
https://git.kernel.org/cgit/linux/kernel/git/andrea/aa.git/log/?h=userfault
I didn't have time to test KVM live memory sn
Hello,
On Tue, Jul 05, 2016 at 11:57:31AM +0200, Baptiste Reynal wrote:
> Ok, if it is not on Andrea schedule I am willing to take the action,
> at least for ARM/ARM64 support.
A few days ago I released this update:
https://git.kernel.org/cgit/linux/kernel/git/andrea/aa.git/
git clone -b master
On Thu, Jun 23, 2016 at 01:44:06AM +0300, Michael S. Tsirkin wrote:
> On Wed, Jun 22, 2016 at 04:24:14PM +0200, Andrea Arcangeli wrote:
> > > cause malfunctioning, only crashes (and as Gerd said, if you cross your
> > > fingers and hope the guest doesn't put
On Thu, Jun 23, 2016 at 01:40:42AM +0300, Michael S. Tsirkin wrote:
> Where's a problem then?
If EPT/NPT is enabled, the guest pagetables are parsed by the hardware
and not by the KVM shadow MMU in software. The hardware speaks host
phys bits and AFIK the hardware will behave different depending o
On Wed, Jun 22, 2016 at 04:33:18PM +0200, Paolo Bonzini wrote:
>
>
> On 22/06/2016 16:24, Andrea Arcangeli wrote:
> > Linux could not possibly crash instead if host phys bits > guest phys
> > bits because it will never depend on GPF triggering if the must be
> > zer
On Wed, Jun 22, 2016 at 04:48:50PM +0200, Paolo Bonzini wrote:
> KVM encodes other information in the sPTE when it sets the reserved bit
> (a generation count). Instead of using all bits up to 51, KVM could
> well use bit MAXPHYADDR+1 as a marker and add bits MAXPHYADDR+2...51 to
> the generation
Hello,
On Wed, Jun 22, 2016 at 02:41:22PM +0200, Paolo Bonzini wrote:
> From a semantics point of view, using a smaller phys-addr-bits than the
> host is the worst, because you tell the guest that some bits are
> must-be-zero, when they're not. Using a larger phys-addr-bits cannot
Ok, so EPT/KVM
On Wed, Apr 27, 2016 at 05:57:30PM +0200, Andrea Arcangeli wrote:
> couldn't do a fix as cleaner as this one for 4.6.
ehm "cleaner then"
If you've suggestions for a better name than PageTransCompoundMap I
can respin a new patch though, I considered "CanMap"
On Wed, Apr 27, 2016 at 06:18:34PM +0300, Kirill A. Shutemov wrote:
> Okay, I see.
>
> But do we really want to make PageTransCompoundMap() visiable beyond KVM
> code? It looks like too KVM-specific.
Any other secondary MMU notifier manager (KVM is just one of the many
MMU notifier users) will ne
On Wed, Apr 27, 2016 at 04:50:30PM +0300, Kirill A. Shutemov wrote:
> I know nothing about kvm. How do you protect against pmd splitting between
> get_user_pages() and the check?
get_user_pages_fast() runs fully lockless and unpins the page right
away (we need a get_user_pages_fast without the FOL
Hello Liang,
On Mon, Apr 18, 2016 at 10:33:14AM +, Li, Liang Z wrote:
> If the THP is disabled, no fails.
> And your test was always passed, even when real post-copy was failed.
>
> In my env, the output of
> 'cat /sys/kernel/mm/transparent_hugepage/enabled' is:
>
> [always] ...
>
Can
ical page split), KVM would map the whole compound page
into the shadow pagetables, despite regular faults or userfaults (like
UFFDIO_COPY) may map regular pages into the primary MMU as result of
the pte faults, leading to the guest mode and userland mode going out
of sync and not working on the same m
On Fri, Apr 15, 2016 at 06:23:30PM +0300, Kirill A. Shutemov wrote:
> The same here. Freshly booted machine with 64GiB ram. I've checked
> /proc/vmstat: huge pages were allocated
I tried the test in a loop and I can't reproduce it here.
Tested with gcc 4.9.3 and glibc 2.21 and glibc 2.22 so far,
Adding linux-mm too,
On Thu, Apr 14, 2016 at 01:34:41PM +0100, Dr. David Alan Gilbert wrote:
> * Andrea Arcangeli (aarca...@redhat.com) wrote:
>
> > The next suspect is the massive THP refcounting change that went
> > upstream recently:
>
> > As further debug hint,
On Wed, Apr 13, 2016 at 01:50:53PM +0100, Dr. David Alan Gilbert wrote:
> * Dr. David Alan Gilbert (dgilb...@redhat.com) wrote:
>
> > +if ( ((b + 1) % 255) == last_byte && !hit_edge) {
>
> Ahem, that should be 256.
>
> I'm going to bisect the kernel and see where we get to.
> Andrea'
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
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
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
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
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
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
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
(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
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
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
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
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
Hello Richard,
On Tue, May 19, 2015 at 11:59:42PM +0200, Richard Weinberger wrote:
> On Tue, May 19, 2015 at 11:38 PM, Andrew Morton
> wrote:
> > On Thu, 14 May 2015 19:30:57 +0200 Andrea Arcangeli
> > wrote:
> >
> >> This is the latest userfaultfd patchset ag
Hi Andrew,
On Tue, May 19, 2015 at 02:38:01PM -0700, Andrew Morton wrote:
> On Thu, 14 May 2015 19:30:57 +0200 Andrea Arcangeli
> wrote:
>
> > This is the latest userfaultfd patchset against mm-v4.1-rc3
> > 2015-05-14-10:04.
>
> It would be useful to have some userf
On Thu, May 14, 2015 at 10:49:06AM -0700, Linus Torvalds wrote:
> On Thu, May 14, 2015 at 10:31 AM, Andrea Arcangeli
> wrote:
> > +static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx,
> > + struct userfaultfd_wake
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 | 96
E. This is even
more significant in case of repeated faults on the same address from
multiple threads.
This optimization is justified by the measurement that the number of
spurious UFFDIO_WAKE accounts for 5% and 10% of the total
userfaults for heavy workloads, so it's worth optimizing
to know when there are new pending userfaults to be
read (POLLIN).
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 1008 ++
1 file changed, 1008 insertions(+)
create mode 100644 fs/userfaultfd.c
diff --git a/fs/userfaultfd.c b/fs
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
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
able overhead.
The total number of new events that can be extended or of new future
bits for already shipped events, is limited to 64 by the features
field of the uffdio_api structure. If more will be needed a bump of
UFFD_API will be required.
Signed-off-by: Andrea Arcangeli
---
Documentation
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/Kbuild| 1 +
include/uapi/linux/userfaultfd.h | 81
3 files
as parameter so the "read|write"
kind of fault can be passed to userland.
Signed-off-by: Andrea Arcangeli
---
mm/huge_memory.c | 69 ++--
mm/memory.c | 16 +
2 files changed, 63 insertions(+), 22 deletions(-)
di
Use proper slab to guarantee alignment.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 39 +++
1 file changed, 31 insertions(+), 8 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 3d26f41..5542fe7 100644
--- a/fs/userfaultfd.c
89fc3b8e338daa58e18
o Extendeded the Documentation userfaultfd.txt file to explain how
QEMU/KVM uses userfaultfd to implement postcopy live migration.
http://git.kernel.org/cgit/linux/kernel/git/andrea/aa.git/commit/?h=userfault&id=016f9523b7b2238851533736e84452cb00b2ddcd
And
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
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 ++-
Add documentation.
Signed-off-by: Andrea Arcangeli
---
Documentation/vm/userfaultfd.txt | 140 +++
1 file changed, 140 insertions(+)
create mode 100644 Documentation/vm/userfaultfd.txt
diff --git a/Documentation/vm/userfaultfd.txt b/Documentation/vm
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
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 c221be3..9671f51 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2198,7 +2198,8 @@ static int __col
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
Update comment.
Signed-off-by: Andrea Arcangeli
---
include/uapi/linux/userfaultfd.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 5e1c2f7..03f21cb 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b
If the rwsem starves writers it wasn't strictly a bug but lockdep
doesn't like it and this avoids depending on lowlevel implementation
details of the lock.
Signed-off-by: Andrea Arcangeli
---
mm/userfaultfd.c | 92
1 file c
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 4 ++--
include/uapi/linux/userfaultfd.h | 10 --
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 1c9be61..9085365 100644
--- a/fs/userfaultfd.c
+++ b/fs
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 0038ac7..2836da7
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 cb92fd4..53e59b2 100644
--- a/fs/Makefile
+++ b/fs
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
This makes read O(1) and poll that was already O(1) becomes lockless.
Signed-off-by: Andrea Arcangeli
---
fs/userfaultfd.c | 172 +++
1 file changed, 98 insertions(+), 74 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index
This activates the userfaultfd syscall.
Signed-off-by: Andrea Arcangeli
---
arch/powerpc/include/asm/systbl.h | 1 +
arch/powerpc/include/uapi/asm/unistd.h | 1 +
arch/x86/syscalls/syscall_32.tbl | 1 +
arch/x86/syscalls/syscall_64.tbl | 1 +
include/linux/syscalls.h
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
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
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 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 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
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
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
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
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
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
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