Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On Thu, Jun 11, 2020 at 11:06:16AM -0400, Andrey Grodzovsky wrote:
>
> On 6/11/20 2:35 AM, Thomas Hellström (Intel) wrote:
> >
> > On 6/10/20 11:19 PM, Andrey Grodzovsky wrote:
> > >
> > > On 6/10/20 4:30 PM, Thomas Hellström (Intel) wrote:
> > > >
> > > > On 6/10/20 5:30 PM, Daniel Vetter wrote:
> > > > > On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
> > > > > > Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
> > > > > > >
> > > > > > > On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
> > > > > > > >
> > > > > > > > On 6/9/20 7:21 PM, Koenig, Christian wrote:
> > > > > > > > >
> > > > > > > > > Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
> > > > > > > > > :
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > On 6/5/20 2:40 PM, Christian König wrote:
> > > > > > > > > > Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
> > > > > > > > > >>
> > > > > > > > > >> On 5/11/20 2:45 AM, Christian König wrote:
> > > > > > > > > >>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
> > > > > > > > > Signed-off-by: Andrey Grodzovsky
> > > > > > > > >
> > > > > > > > > ---
> > > > > > > > > drivers/gpu/drm/ttm/ttm_bo.c | 22
> > > > > > > > > +-
> > > > > > > > > include/drm/ttm/ttm_bo_driver.h | 2 ++
> > > > > > > > > 2 files changed, 23 insertions(+), 1 deletion(-)
> > > > > > > > >
> > > > > > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > > b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > > index c5b516f..eae61cc 100644
> > > > > > > > > --- a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > > +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > > @@ -1750,9 +1750,29 @@ void
> > > > > > > > > ttm_bo_unmap_virtual(struct
> > > > > > > > > ttm_buffer_object *bo)
> > > > > > > > > ttm_bo_unmap_virtual_locked(bo);
> > > > > > > > > ttm_mem_io_unlock(man);
> > > > > > > > > }
> > > > > > > > > +EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > > > > > > +void ttm_bo_unmap_virtual_address_space(struct
> > > > > > > > > ttm_bo_device *bdev)
> > > > > > > > > +{
> > > > > > > > > + struct ttm_mem_type_manager *man;
> > > > > > > > > + int i;
> > > > > > > > > -EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > > > > > > >>>
> > > > > > > > > + for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
> > > > > > > > > + man = >man[i];
> > > > > > > > > + if (man->has_type && man->use_type)
> > > > > > > > > + ttm_mem_io_lock(man, false);
> > > > > > > > > + }
> > > > > > > > > >>>
> > > > > > > > > >>> You should drop that it will just result in a
> > > > > > > > > deadlock
> > > > > > > > > warning for
> > > > > > > > > >>> Nouveau and has no effect at all.
> > > > > > > > > >>>
> > > > > > > > > >>> Apart from that looks good to me,
> > > > > > > > > >>> Christian.
> > > > > > > > > >>
> > > > > > > > > >>
> > > > > > > > > >> As I am considering to re-include this in V2 of the
> > > > > > > > > patchsets, can
> > > > > > > > > >> you clarify please why this will have no effect at
> > > > > > > > > all ?
> > > > > > > > > >
> > > > > > > > > > The locks are exclusive for Nouveau to allocate/free
> > > > > > > > > the io
> > > > > > > > > address
> > > > > > > > > > space.
> > > > > > > > > >
> > > > > > > > > > Since we don't do this here we don't need the locks.
> > > > > > > > > >
> > > > > > > > > > Christian.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > So basically calling
> > > > > > > > > unmap_mapping_range doesn't require any
> > > > > > > > > extra
> > > > > > > > > locking around it and whatever locks
> > > > > > > > > are taken within the function
> > > > > > > > > should be enough ?
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > I think so, yes.
> > > > > > > > >
> > > > > > > > > Christian.
> > > > > > > > Yes, that's true. However, without the bo
> > > > > > > > reservation, nothing stops
> > > > > > > > a PTE from being immediately re-faulted back again. Even while
> > > > > > > > unmap_mapping_range() is running.
> > > > > > > >
> > > > > > > Can you explain more on this - specifically, which
> > > > > > > function to reserve
> > > > > > > the BO, why BO reservation would prevent re-fault of the PTE ?
> > > > > > >
> > > > > > Thomas is talking about
> > > > > > ttm_bo_reserver()/ttm_bo_unreserve(), but we don't
> > > > > > need this because we unmap everything because the whole
> > > > > > device is gone and
> > > > > > not just manipulate a single BO.
> > > > > >
> > > > > > > > So the device removed flag needs to be advertized before this
> > > > > > > > function is run,
>
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On Thu, Jun 11, 2020 at 11:15:42AM -0400, Andrey Grodzovsky wrote:
>
> On 6/10/20 5:16 PM, Daniel Vetter wrote:
> > On Wed, Jun 10, 2020 at 10:30 PM Thomas Hellström (Intel)
> > wrote:
> > >
> > > On 6/10/20 5:30 PM, Daniel Vetter wrote:
> > > > On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
> > > > > Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
> > > > > > On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
> > > > > > > On 6/9/20 7:21 PM, Koenig, Christian wrote:
> > > > > > > > Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
> > > > > > > > :
> > > > > > > >
> > > > > > > >
> > > > > > > > On 6/5/20 2:40 PM, Christian König wrote:
> > > > > > > > > Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
> > > > > > > > >>
> > > > > > > > >> On 5/11/20 2:45 AM, Christian König wrote:
> > > > > > > > >>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
> > > > > > > > Signed-off-by: Andrey Grodzovsky
> > > > > > > >
> > > > > > > > ---
> > > > > > > > drivers/gpu/drm/ttm/ttm_bo.c| 22
> > > > > > > > +-
> > > > > > > > include/drm/ttm/ttm_bo_driver.h | 2 ++
> > > > > > > > 2 files changed, 23 insertions(+), 1 deletion(-)
> > > > > > > >
> > > > > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > index c5b516f..eae61cc 100644
> > > > > > > > --- a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > @@ -1750,9 +1750,29 @@ void
> > > > > > > > ttm_bo_unmap_virtual(struct
> > > > > > > > ttm_buffer_object *bo)
> > > > > > > > ttm_bo_unmap_virtual_locked(bo);
> > > > > > > > ttm_mem_io_unlock(man);
> > > > > > > > }
> > > > > > > > +EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > > > > > +void ttm_bo_unmap_virtual_address_space(struct
> > > > > > > > ttm_bo_device *bdev)
> > > > > > > > +{
> > > > > > > > +struct ttm_mem_type_manager *man;
> > > > > > > > +int i;
> > > > > > > > -EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > > > > > >>>
> > > > > > > > +for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
> > > > > > > > +man = >man[i];
> > > > > > > > +if (man->has_type && man->use_type)
> > > > > > > > + ttm_mem_io_lock(man, false);
> > > > > > > > +}
> > > > > > > > >>>
> > > > > > > > >>> You should drop that it will just result in a deadlock
> > > > > > > > warning for
> > > > > > > > >>> Nouveau and has no effect at all.
> > > > > > > > >>>
> > > > > > > > >>> Apart from that looks good to me,
> > > > > > > > >>> Christian.
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >> As I am considering to re-include this in V2 of the
> > > > > > > > patchsets, can
> > > > > > > > >> you clarify please why this will have no effect at all
> > > > > > > > ?
> > > > > > > > >
> > > > > > > > > The locks are exclusive for Nouveau to allocate/free
> > > > > > > > the io
> > > > > > > > address
> > > > > > > > > space.
> > > > > > > > >
> > > > > > > > > Since we don't do this here we don't need the locks.
> > > > > > > > >
> > > > > > > > > Christian.
> > > > > > > >
> > > > > > > >
> > > > > > > > So basically calling unmap_mapping_range doesn't require
> > > > > > > > any extra
> > > > > > > > locking around it and whatever locks are taken within the
> > > > > > > > function
> > > > > > > > should be enough ?
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > I think so, yes.
> > > > > > > >
> > > > > > > > Christian.
> > > > > > > Yes, that's true. However, without the bo reservation, nothing
> > > > > > > stops
> > > > > > > a PTE from being immediately re-faulted back again. Even while
> > > > > > > unmap_mapping_range() is running.
> > > > > > >
> > > > > > Can you explain more on this - specifically, which function to
> > > > > > reserve
> > > > > > the BO, why BO reservation would prevent re-fault of the PTE ?
> > > > > >
> > > > > Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we
> > > > > don't
> > > > > need this because we unmap everything because the whole device is
> > > > > gone and
> > > > > not just manipulate a single BO.
> > > > >
> > > > > > > So the device removed flag needs to be advertized before this
> > > > > > > function is run,
> > > > > > >
> > > > > > I indeed intend to call this right after calling drm_dev_unplug
> > > > > > from
> > > > > > amdgpu_pci_remove while adding drm_dev_enter/exit in
> > > > > > ttm_bo_vm_fault (or
> > > > > > in amdgpu specific wrapper since I don't see how can I
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/10/20 5:16 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 10:30 PM Thomas Hellström (Intel)
wrote:
On 6/10/20 5:30 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c| 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+struct ttm_mem_type_manager *man;
+int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+man = >man[i];
+if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+}
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we don't
need this because we unmap everything because the whole device is gone and
not just manipulate a single BO.
So the device removed flag needs to be advertized before this
function is run,
I indeed intend to call this right after calling drm_dev_unplug from
amdgpu_pci_remove while adding drm_dev_enter/exit in ttm_bo_vm_fault (or
in amdgpu specific wrapper since I don't see how can I access struct
drm_device from ttm_bo_vm_fault) and this in my understanding should
stop a PTE from being re-faulted back as you pointed out - so again I
don't see how bo reservation would prevent it so it looks like I am
missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
As far as I can see that should be perfectly sufficient.
Only if you have a drm_dev_enter/exit pair in your fault handler.
Otherwise you're still open to the races Thomas described. But aside from
that the drm_dev_unplug stuff has all the barriers and stuff to make sure
nothing escapes.
Failure to drm_dev_enter could then also trigger the special case where we
put a dummy page in place.
-Daniel
Hmm, Yes, indeed advertizing the flag before the call to
unmap_mapping_range isn't enough, since there might be fault handlers
running that haven't picked up the flag when unmap_mapping_range is
launched.
Hm ... Now I'm not sure drm_dev_enter/exit is actually good enough. I
guess if you use vmf_insert_pfn within the drm_dev_enter/exit critical
section, it should be fine. But I think you can also do fault handlers
that just return the struct page and then let core handle the pte
wrangling, those would indeed race and we can't have that I think.
I think we should try and make sure (as much as possible) that this is
done all done in helpers and not some open coded stuff in drivers, or
we'll just get it all wrong in the details.
Can you please clarify this last paragraph ?
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/11/20 2:35 AM, Thomas Hellström (Intel) wrote:
On 6/10/20 11:19 PM, Andrey Grodzovsky wrote:
On 6/10/20 4:30 PM, Thomas Hellström (Intel) wrote:
On 6/10/20 5:30 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require
any extra
locking around it and whatever locks are taken within the
function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing
stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to
reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but
we don't
need this because we unmap everything because the whole device is
gone and
not just manipulate a single BO.
So the device removed flag needs to be advertized before this
function is run,
I indeed intend to call this right after calling drm_dev_unplug
from
amdgpu_pci_remove while adding drm_dev_enter/exit in
ttm_bo_vm_fault (or
in amdgpu specific wrapper since I don't see how can I access struct
drm_device from ttm_bo_vm_fault) and this in my understanding should
stop a PTE from being re-faulted back as you pointed out - so
again I
don't see how bo reservation would prevent it so it looks like I am
missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
As far as I can see that should be perfectly sufficient.
Only if you have a drm_dev_enter/exit pair in your fault handler.
Otherwise you're still open to the races Thomas described. But
aside from
that the drm_dev_unplug stuff has all the barriers and stuff to
make sure
nothing escapes.
Failure to drm_dev_enter could then also trigger the special case
where we
put a dummy page in place.
-Daniel
Hmm, Yes, indeed advertizing the flag before the call to
unmap_mapping_range isn't enough, since there might be fault
handlers running that haven't picked up the flag when
unmap_mapping_range is launched.
If you mean those fault handlers that were in progress when the flag
(drm_dev_unplug) was set in amdgpu_pci_remove then as long as i wrap
the entire fault handler (probably using amdgpu specific .fault hook
around ttm_bo_vm_fault) with drm_dev_enter/exit pair then
drm_dev_unplug->synchronize_srcu will block until those in progress
faults have completed and only after this i will call
unmap_mapping_range. Should this be enough ?
Andrey
Yes, I believe so. Although I suspect you might trip lockdep with
reverse locking order against the mmap_sem which
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On Thu, Jun 11, 2020 at 08:12:37AM +0200, Thomas Hellström (Intel) wrote:
>
> On 6/10/20 11:16 PM, Daniel Vetter wrote:
> > On Wed, Jun 10, 2020 at 10:30 PM Thomas Hellström (Intel)
> > wrote:
> > >
> > > On 6/10/20 5:30 PM, Daniel Vetter wrote:
> > > > On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
> > > > > Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
> > > > > > On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
> > > > > > > On 6/9/20 7:21 PM, Koenig, Christian wrote:
> > > > > > > > Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
> > > > > > > > :
> > > > > > > >
> > > > > > > >
> > > > > > > > On 6/5/20 2:40 PM, Christian König wrote:
> > > > > > > > > Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
> > > > > > > > >>
> > > > > > > > >> On 5/11/20 2:45 AM, Christian König wrote:
> > > > > > > > >>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
> > > > > > > > Signed-off-by: Andrey Grodzovsky
> > > > > > > >
> > > > > > > > ---
> > > > > > > > drivers/gpu/drm/ttm/ttm_bo.c| 22
> > > > > > > > +-
> > > > > > > > include/drm/ttm/ttm_bo_driver.h | 2 ++
> > > > > > > > 2 files changed, 23 insertions(+), 1 deletion(-)
> > > > > > > >
> > > > > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > index c5b516f..eae61cc 100644
> > > > > > > > --- a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > > > > > @@ -1750,9 +1750,29 @@ void
> > > > > > > > ttm_bo_unmap_virtual(struct
> > > > > > > > ttm_buffer_object *bo)
> > > > > > > > ttm_bo_unmap_virtual_locked(bo);
> > > > > > > > ttm_mem_io_unlock(man);
> > > > > > > > }
> > > > > > > > +EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > > > > > +void ttm_bo_unmap_virtual_address_space(struct
> > > > > > > > ttm_bo_device *bdev)
> > > > > > > > +{
> > > > > > > > +struct ttm_mem_type_manager *man;
> > > > > > > > +int i;
> > > > > > > > -EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > > > > > >>>
> > > > > > > > +for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
> > > > > > > > +man = >man[i];
> > > > > > > > +if (man->has_type && man->use_type)
> > > > > > > > + ttm_mem_io_lock(man, false);
> > > > > > > > +}
> > > > > > > > >>>
> > > > > > > > >>> You should drop that it will just result in a deadlock
> > > > > > > > warning for
> > > > > > > > >>> Nouveau and has no effect at all.
> > > > > > > > >>>
> > > > > > > > >>> Apart from that looks good to me,
> > > > > > > > >>> Christian.
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >> As I am considering to re-include this in V2 of the
> > > > > > > > patchsets, can
> > > > > > > > >> you clarify please why this will have no effect at all
> > > > > > > > ?
> > > > > > > > >
> > > > > > > > > The locks are exclusive for Nouveau to allocate/free
> > > > > > > > the io
> > > > > > > > address
> > > > > > > > > space.
> > > > > > > > >
> > > > > > > > > Since we don't do this here we don't need the locks.
> > > > > > > > >
> > > > > > > > > Christian.
> > > > > > > >
> > > > > > > >
> > > > > > > > So basically calling unmap_mapping_range doesn't require
> > > > > > > > any extra
> > > > > > > > locking around it and whatever locks are taken within the
> > > > > > > > function
> > > > > > > > should be enough ?
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > I think so, yes.
> > > > > > > >
> > > > > > > > Christian.
> > > > > > > Yes, that's true. However, without the bo reservation, nothing
> > > > > > > stops
> > > > > > > a PTE from being immediately re-faulted back again. Even while
> > > > > > > unmap_mapping_range() is running.
> > > > > > >
> > > > > > Can you explain more on this - specifically, which function to
> > > > > > reserve
> > > > > > the BO, why BO reservation would prevent re-fault of the PTE ?
> > > > > >
> > > > > Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we
> > > > > don't
> > > > > need this because we unmap everything because the whole device is
> > > > > gone and
> > > > > not just manipulate a single BO.
> > > > >
> > > > > > > So the device removed flag needs to be advertized before this
> > > > > > > function is run,
> > > > > > >
> > > > > > I indeed intend to call this right after calling drm_dev_unplug
> > > > > > from
> > > > > > amdgpu_pci_remove while adding drm_dev_enter/exit in
> > > > > > ttm_bo_vm_fault (or
> > > > > > in amdgpu specific wrapper since I don't see how
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/10/20 11:19 PM, Andrey Grodzovsky wrote:
On 6/10/20 4:30 PM, Thomas Hellström (Intel) wrote:
On 6/10/20 5:30 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require
any extra
locking around it and whatever locks are taken within the
function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to
reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but
we don't
need this because we unmap everything because the whole device is
gone and
not just manipulate a single BO.
So the device removed flag needs to be advertized before this
function is run,
I indeed intend to call this right after calling drm_dev_unplug from
amdgpu_pci_remove while adding drm_dev_enter/exit in
ttm_bo_vm_fault (or
in amdgpu specific wrapper since I don't see how can I access struct
drm_device from ttm_bo_vm_fault) and this in my understanding should
stop a PTE from being re-faulted back as you pointed out - so again I
don't see how bo reservation would prevent it so it looks like I am
missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
As far as I can see that should be perfectly sufficient.
Only if you have a drm_dev_enter/exit pair in your fault handler.
Otherwise you're still open to the races Thomas described. But aside
from
that the drm_dev_unplug stuff has all the barriers and stuff to make
sure
nothing escapes.
Failure to drm_dev_enter could then also trigger the special case
where we
put a dummy page in place.
-Daniel
Hmm, Yes, indeed advertizing the flag before the call to
unmap_mapping_range isn't enough, since there might be fault handlers
running that haven't picked up the flag when unmap_mapping_range is
launched.
If you mean those fault handlers that were in progress when the flag
(drm_dev_unplug) was set in amdgpu_pci_remove then as long as i wrap
the entire fault handler (probably using amdgpu specific .fault hook
around ttm_bo_vm_fault) with drm_dev_enter/exit pair then
drm_dev_unplug->synchronize_srcu will block until those in progress
faults have completed and only after this i will call
unmap_mapping_range. Should this be enough ?
Andrey
Yes, I believe so. Although I suspect you might trip lockdep with
reverse locking order against the mmap_sem which is a constant pain in
fault handlers. If that's the case,
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/10/20 11:16 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 10:30 PM Thomas Hellström (Intel)
wrote:
On 6/10/20 5:30 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c| 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+struct ttm_mem_type_manager *man;
+int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+man = >man[i];
+if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+}
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we don't
need this because we unmap everything because the whole device is gone and
not just manipulate a single BO.
So the device removed flag needs to be advertized before this
function is run,
I indeed intend to call this right after calling drm_dev_unplug from
amdgpu_pci_remove while adding drm_dev_enter/exit in ttm_bo_vm_fault (or
in amdgpu specific wrapper since I don't see how can I access struct
drm_device from ttm_bo_vm_fault) and this in my understanding should
stop a PTE from being re-faulted back as you pointed out - so again I
don't see how bo reservation would prevent it so it looks like I am
missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
As far as I can see that should be perfectly sufficient.
Only if you have a drm_dev_enter/exit pair in your fault handler.
Otherwise you're still open to the races Thomas described. But aside from
that the drm_dev_unplug stuff has all the barriers and stuff to make sure
nothing escapes.
Failure to drm_dev_enter could then also trigger the special case where we
put a dummy page in place.
-Daniel
Hmm, Yes, indeed advertizing the flag before the call to
unmap_mapping_range isn't enough, since there might be fault handlers
running that haven't picked up the flag when unmap_mapping_range is
launched.
Hm ... Now I'm not sure drm_dev_enter/exit is actually good enough. I
guess if you use vmf_insert_pfn within the drm_dev_enter/exit critical
section, it should be fine. But I think you can also do fault handlers
that just return the struct page and then let core handle the pte
wrangling, those would indeed race and we can't have that I think.
For the TTM drivers, having a fault handler that defers the pte
insertion to the core would break also the bo synchronization so I don't
think that will ever happen. To make sure we could perhaps add a return
value warning at
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/10/20 4:30 PM, Thomas Hellström (Intel) wrote:
On 6/10/20 5:30 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22
+-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any
extra
locking around it and whatever locks are taken within the
function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we
don't
need this because we unmap everything because the whole device is
gone and
not just manipulate a single BO.
So the device removed flag needs to be advertized before this
function is run,
I indeed intend to call this right after calling drm_dev_unplug from
amdgpu_pci_remove while adding drm_dev_enter/exit in
ttm_bo_vm_fault (or
in amdgpu specific wrapper since I don't see how can I access struct
drm_device from ttm_bo_vm_fault) and this in my understanding should
stop a PTE from being re-faulted back as you pointed out - so again I
don't see how bo reservation would prevent it so it looks like I am
missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
As far as I can see that should be perfectly sufficient.
Only if you have a drm_dev_enter/exit pair in your fault handler.
Otherwise you're still open to the races Thomas described. But aside
from
that the drm_dev_unplug stuff has all the barriers and stuff to make
sure
nothing escapes.
Failure to drm_dev_enter could then also trigger the special case
where we
put a dummy page in place.
-Daniel
Hmm, Yes, indeed advertizing the flag before the call to
unmap_mapping_range isn't enough, since there might be fault handlers
running that haven't picked up the flag when unmap_mapping_range is
launched.
If you mean those fault handlers that were in progress when the flag
(drm_dev_unplug) was set in amdgpu_pci_remove then as long as i wrap the
entire fault handler (probably using amdgpu specific .fault hook around
ttm_bo_vm_fault) with drm_dev_enter/exit pair then
drm_dev_unplug->synchronize_srcu will block until those in progress
faults have completed and only after this i will call
unmap_mapping_range. Should this be enough ?
Andrey
For the special case of syncing a full address-space
unmap_mapping_range() with fault handlers regardless of the reason for
the full address-space unmap_mapping_range() one could either traverse
the address space
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On Wed, Jun 10, 2020 at 10:30 PM Thomas Hellström (Intel)
wrote:
>
>
> On 6/10/20 5:30 PM, Daniel Vetter wrote:
> > On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
> >> Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
> >>>
> >>> On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
>
> On 6/9/20 7:21 PM, Koenig, Christian wrote:
> >
> > Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
> > :
> >
> >
> > On 6/5/20 2:40 PM, Christian König wrote:
> > > Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
> > >>
> > >> On 5/11/20 2:45 AM, Christian König wrote:
> > >>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
> > Signed-off-by: Andrey Grodzovsky
> > ---
> > drivers/gpu/drm/ttm/ttm_bo.c| 22 +-
> > include/drm/ttm/ttm_bo_driver.h | 2 ++
> > 2 files changed, 23 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
> > b/drivers/gpu/drm/ttm/ttm_bo.c
> > index c5b516f..eae61cc 100644
> > --- a/drivers/gpu/drm/ttm/ttm_bo.c
> > +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> > @@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
> > ttm_buffer_object *bo)
> > ttm_bo_unmap_virtual_locked(bo);
> > ttm_mem_io_unlock(man);
> > }
> > +EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > +void ttm_bo_unmap_virtual_address_space(struct
> > ttm_bo_device *bdev)
> > +{
> > +struct ttm_mem_type_manager *man;
> > +int i;
> > -EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > >>>
> > +for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
> > +man = >man[i];
> > +if (man->has_type && man->use_type)
> > + ttm_mem_io_lock(man, false);
> > +}
> > >>>
> > >>> You should drop that it will just result in a deadlock
> > warning for
> > >>> Nouveau and has no effect at all.
> > >>>
> > >>> Apart from that looks good to me,
> > >>> Christian.
> > >>
> > >>
> > >> As I am considering to re-include this in V2 of the
> > patchsets, can
> > >> you clarify please why this will have no effect at all ?
> > >
> > > The locks are exclusive for Nouveau to allocate/free the io
> > address
> > > space.
> > >
> > > Since we don't do this here we don't need the locks.
> > >
> > > Christian.
> >
> >
> > So basically calling unmap_mapping_range doesn't require any extra
> > locking around it and whatever locks are taken within the function
> > should be enough ?
> >
> >
> >
> > I think so, yes.
> >
> > Christian.
> Yes, that's true. However, without the bo reservation, nothing stops
> a PTE from being immediately re-faulted back again. Even while
> unmap_mapping_range() is running.
>
> >>> Can you explain more on this - specifically, which function to reserve
> >>> the BO, why BO reservation would prevent re-fault of the PTE ?
> >>>
> >> Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we don't
> >> need this because we unmap everything because the whole device is gone and
> >> not just manipulate a single BO.
> >>
> So the device removed flag needs to be advertized before this
> function is run,
>
> >>> I indeed intend to call this right after calling drm_dev_unplug from
> >>> amdgpu_pci_remove while adding drm_dev_enter/exit in ttm_bo_vm_fault (or
> >>> in amdgpu specific wrapper since I don't see how can I access struct
> >>> drm_device from ttm_bo_vm_fault) and this in my understanding should
> >>> stop a PTE from being re-faulted back as you pointed out - so again I
> >>> don't see how bo reservation would prevent it so it looks like I am
> >>> missing something...
> >>>
> >>>
> (perhaps with a memory barrier pair).
>
> >>> drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
> >>> don't think require any extra memory barriers for visibility of the
> >>> removed flag being set
> >>>
> >> As far as I can see that should be perfectly sufficient.
> > Only if you have a drm_dev_enter/exit pair in your fault handler.
> > Otherwise you're still open to the races Thomas described. But aside from
> > that the drm_dev_unplug stuff has all the barriers and stuff to make sure
> > nothing escapes.
> >
> > Failure to drm_dev_enter could then also trigger the special case where we
> > put a dummy page in place.
> > -Daniel
>
> Hmm, Yes, indeed advertizing the flag before the call to
> unmap_mapping_range isn't enough, since
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/10/20 5:30 PM, Daniel Vetter wrote:
On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we don't
need this because we unmap everything because the whole device is gone and
not just manipulate a single BO.
So the device removed flag needs to be advertized before this
function is run,
I indeed intend to call this right after calling drm_dev_unplug from
amdgpu_pci_remove while adding drm_dev_enter/exit in ttm_bo_vm_fault (or
in amdgpu specific wrapper since I don't see how can I access struct
drm_device from ttm_bo_vm_fault) and this in my understanding should
stop a PTE from being re-faulted back as you pointed out - so again I
don't see how bo reservation would prevent it so it looks like I am
missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
As far as I can see that should be perfectly sufficient.
Only if you have a drm_dev_enter/exit pair in your fault handler.
Otherwise you're still open to the races Thomas described. But aside from
that the drm_dev_unplug stuff has all the barriers and stuff to make sure
nothing escapes.
Failure to drm_dev_enter could then also trigger the special case where we
put a dummy page in place.
-Daniel
Hmm, Yes, indeed advertizing the flag before the call to
unmap_mapping_range isn't enough, since there might be fault handlers
running that haven't picked up the flag when unmap_mapping_range is
launched.
For the special case of syncing a full address-space
unmap_mapping_range() with fault handlers regardless of the reason for
the full address-space unmap_mapping_range() one could either traverse
the address space (drm_vma_manager) and grab *all* bo reservations
around the unmap_mapping_range(), or grab the i_mmap_lock in read mode
in the fault handler. (It's taken in write mode in unmap_mapping_range).
While the latter may seem like a simple solution, one should probably
consider the overhead both in run-time and scaling ability.
/Thomas
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On Wed, Jun 10, 2020 at 04:05:04PM +0200, Christian König wrote:
> Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
> >
> >
> > On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
> > >
> > >
> > > On 6/9/20 7:21 PM, Koenig, Christian wrote:
> > > >
> > > >
> > > > Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
> > > > :
> > > >
> > > >
> > > > On 6/5/20 2:40 PM, Christian König wrote:
> > > > > Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
> > > > >>
> > > > >> On 5/11/20 2:45 AM, Christian König wrote:
> > > > >>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
> > > > Signed-off-by: Andrey Grodzovsky
> > > > ---
> > > > drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
> > > > include/drm/ttm/ttm_bo_driver.h | 2 ++
> > > > 2 files changed, 23 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > index c5b516f..eae61cc 100644
> > > > --- a/drivers/gpu/drm/ttm/ttm_bo.c
> > > > +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> > > > @@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
> > > > ttm_buffer_object *bo)
> > > > ttm_bo_unmap_virtual_locked(bo);
> > > > ttm_mem_io_unlock(man);
> > > > }
> > > > +EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > +void ttm_bo_unmap_virtual_address_space(struct
> > > > ttm_bo_device *bdev)
> > > > +{
> > > > + struct ttm_mem_type_manager *man;
> > > > + int i;
> > > > -EXPORT_SYMBOL(ttm_bo_unmap_virtual);
> > > > >>>
> > > > + for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
> > > > + man = >man[i];
> > > > + if (man->has_type && man->use_type)
> > > > + ttm_mem_io_lock(man, false);
> > > > + }
> > > > >>>
> > > > >>> You should drop that it will just result in a deadlock
> > > > warning for
> > > > >>> Nouveau and has no effect at all.
> > > > >>>
> > > > >>> Apart from that looks good to me,
> > > > >>> Christian.
> > > > >>
> > > > >>
> > > > >> As I am considering to re-include this in V2 of the
> > > > patchsets, can
> > > > >> you clarify please why this will have no effect at all ?
> > > > >
> > > > > The locks are exclusive for Nouveau to allocate/free the io
> > > > address
> > > > > space.
> > > > >
> > > > > Since we don't do this here we don't need the locks.
> > > > >
> > > > > Christian.
> > > >
> > > >
> > > > So basically calling unmap_mapping_range doesn't require any extra
> > > > locking around it and whatever locks are taken within the function
> > > > should be enough ?
> > > >
> > > >
> > > >
> > > > I think so, yes.
> > > >
> > > > Christian.
> > >
> > > Yes, that's true. However, without the bo reservation, nothing stops
> > > a PTE from being immediately re-faulted back again. Even while
> > > unmap_mapping_range() is running.
> > >
> >
> > Can you explain more on this - specifically, which function to reserve
> > the BO, why BO reservation would prevent re-fault of the PTE ?
> >
>
> Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we don't
> need this because we unmap everything because the whole device is gone and
> not just manipulate a single BO.
>
> >
> > > So the device removed flag needs to be advertized before this
> > > function is run,
> > >
> >
> > I indeed intend to call this right after calling drm_dev_unplug from
> > amdgpu_pci_remove while adding drm_dev_enter/exit in ttm_bo_vm_fault (or
> > in amdgpu specific wrapper since I don't see how can I access struct
> > drm_device from ttm_bo_vm_fault) and this in my understanding should
> > stop a PTE from being re-faulted back as you pointed out - so again I
> > don't see how bo reservation would prevent it so it looks like I am
> > missing something...
> >
> >
> > > (perhaps with a memory barrier pair).
> > >
> >
> > drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
> > don't think require any extra memory barriers for visibility of the
> > removed flag being set
> >
>
> As far as I can see that should be perfectly sufficient.
Only if you have a drm_dev_enter/exit pair in your fault handler.
Otherwise you're still open to the races Thomas described. But aside from
that the drm_dev_unplug stuff has all the barriers and stuff to make sure
nothing escapes.
Failure to drm_dev_enter could then also trigger the special case where we
put a dummy page in place.
-Daniel
>
> Christian.
>
> >
> > Andrey
> >
> >
> > > That should probably be added to the function documentation.
> > >
> > > (Other than that, please add a commit message if respinning).
> > >
> > > /Thomas
> > >
> > >
> > >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/10/20 3:54 PM, Andrey Grodzovsky wrote:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
The bo reservation is taken in the TTM fault handler and temporarily
blocks inserting a new PTE. So typically the bo reservation is held
around unmap_mapping_range() and the buffer object operation that
triggered it (typically a move or change of backing store).
/Thomas
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
Am 10.06.20 um 15:54 schrieb Andrey Grodzovsky:
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the
patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops
a PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
Thomas is talking about ttm_bo_reserver()/ttm_bo_unreserve(), but we
don't need this because we unmap everything because the whole device is
gone and not just manipulate a single BO.
So the device removed flag needs to be advertized before this
function is run,
I indeed intend to call this right after calling drm_dev_unplug from
amdgpu_pci_remove while adding drm_dev_enter/exit in ttm_bo_vm_fault
(or in amdgpu specific wrapper since I don't see how can I access
struct drm_device from ttm_bo_vm_fault) and this in my understanding
should stop a PTE from being re-faulted back as you pointed out - so
again I don't see how bo reservation would prevent it so it looks
like I am missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
As far as I can see that should be perfectly sufficient.
Christian.
Andrey
That should probably be added to the function documentation.
(Other than that, please add a commit message if respinning).
/Thomas
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/10/20 6:15 AM, Thomas Hellström (Intel) wrote:
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock
warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the patchsets,
can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io
address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops a
PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running.
Can you explain more on this - specifically, which function to reserve
the BO, why BO reservation would prevent re-fault of the PTE ?
So the device removed flag needs to be advertized before this function
is run,
I indeed intend to call this right after calling drm_dev_unplug from
amdgpu_pci_remove while adding drm_dev_enter/exit in ttm_bo_vm_fault (or
in amdgpu specific wrapper since I don't see how can I access struct
drm_device from ttm_bo_vm_fault) and this in my understanding should
stop a PTE from being re-faulted back as you pointed out - so again I
don't see how bo reservation would prevent it so it looks like I am
missing something...
(perhaps with a memory barrier pair).
drm_dev_unplug and drm_dev_enter/exit are RCU synchronized and so I
don't think require any extra memory barriers for visibility of the
removed flag being set
Andrey
That should probably be added to the function documentation.
(Other than that, please add a commit message if respinning).
/Thomas
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/9/20 7:21 PM, Koenig, Christian wrote:
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey"
:
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct
ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
>>>
>>> You should drop that it will just result in a deadlock warning
for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Yes, that's true. However, without the bo reservation, nothing stops a
PTE from being immediately re-faulted back again. Even while
unmap_mapping_range() is running. So the device removed flag needs to be
advertized before this function is run, (perhaps with a memory barrier
pair). That should probably be added to the function documentation.
(Other than that, please add a commit message if respinning).
/Thomas
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
Am 09.06.2020 18:37 schrieb "Grodzovsky, Andrey" :
On 6/5/20 2:40 PM, Christian König wrote:
> Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
>>
>> On 5/11/20 2:45 AM, Christian König wrote:
>>> Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c| 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev)
+{
+struct ttm_mem_type_manager *man;
+int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
>>>
+for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+man = >man[i];
+if (man->has_type && man->use_type)
+ttm_mem_io_lock(man, false);
+}
>>>
>>> You should drop that it will just result in a deadlock warning for
>>> Nouveau and has no effect at all.
>>>
>>> Apart from that looks good to me,
>>> Christian.
>>
>>
>> As I am considering to re-include this in V2 of the patchsets, can
>> you clarify please why this will have no effect at all ?
>
> The locks are exclusive for Nouveau to allocate/free the io address
> space.
>
> Since we don't do this here we don't need the locks.
>
> Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
I think so, yes.
Christian.
Andrey
>
>>
>> Andrey
>>
>>
>>>
+
+unmap_mapping_range(bdev->dev_mapping, 0, 0 , 1);
+/*TODO What about ttm_mem_io_free_vm(bo) ? */
+
+for (i = TTM_NUM_MEM_TYPES - 1; i >= 0; i--) {
+man = >man[i];
+if (man->has_type && man->use_type)
+ttm_mem_io_unlock(man);
+}
+}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual_address_space);
int ttm_bo_wait(struct ttm_buffer_object *bo,
bool interruptible, bool no_wait)
diff --git a/include/drm/ttm/ttm_bo_driver.h
b/include/drm/ttm/ttm_bo_driver.h
index c9e0fd0..3133463 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -600,6 +600,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
*/
void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device
*bdev);
+
/**
* ttm_bo_unmap_virtual
*
>>>
>
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 6/5/20 2:40 PM, Christian König wrote:
Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
On 5/11/20 2:45 AM, Christian König wrote:
Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
You should drop that it will just result in a deadlock warning for
Nouveau and has no effect at all.
Apart from that looks good to me,
Christian.
As I am considering to re-include this in V2 of the patchsets, can
you clarify please why this will have no effect at all ?
The locks are exclusive for Nouveau to allocate/free the io address
space.
Since we don't do this here we don't need the locks.
Christian.
So basically calling unmap_mapping_range doesn't require any extra
locking around it and whatever locks are taken within the function
should be enough ?
Andrey
Andrey
+
+ unmap_mapping_range(bdev->dev_mapping, 0, 0 , 1);
+ /*TODO What about ttm_mem_io_free_vm(bo) ? */
+
+ for (i = TTM_NUM_MEM_TYPES - 1; i >= 0; i--) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_unlock(man);
+ }
+}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual_address_space);
int ttm_bo_wait(struct ttm_buffer_object *bo,
bool interruptible, bool no_wait)
diff --git a/include/drm/ttm/ttm_bo_driver.h
b/include/drm/ttm/ttm_bo_driver.h
index c9e0fd0..3133463 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -600,6 +600,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
*/
void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device
*bdev);
+
/**
* ttm_bo_unmap_virtual
*
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
Am 05.06.20 um 16:29 schrieb Andrey Grodzovsky:
On 5/11/20 2:45 AM, Christian König wrote:
Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
You should drop that it will just result in a deadlock warning for
Nouveau and has no effect at all.
Apart from that looks good to me,
Christian.
As I am considering to re-include this in V2 of the patchsets, can you
clarify please why this will have no effect at all ?
The locks are exclusive for Nouveau to allocate/free the io address space.
Since we don't do this here we don't need the locks.
Christian.
Andrey
+
+ unmap_mapping_range(bdev->dev_mapping, 0, 0 , 1);
+ /*TODO What about ttm_mem_io_free_vm(bo) ? */
+
+ for (i = TTM_NUM_MEM_TYPES - 1; i >= 0; i--) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_unlock(man);
+ }
+}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual_address_space);
int ttm_bo_wait(struct ttm_buffer_object *bo,
bool interruptible, bool no_wait)
diff --git a/include/drm/ttm/ttm_bo_driver.h
b/include/drm/ttm/ttm_bo_driver.h
index c9e0fd0..3133463 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -600,6 +600,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
*/
void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev);
+
/**
* ttm_bo_unmap_virtual
*
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
On 5/11/20 2:45 AM, Christian König wrote:
Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c | 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct
ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
You should drop that it will just result in a deadlock warning for
Nouveau and has no effect at all.
Apart from that looks good to me,
Christian.
As I am considering to re-include this in V2 of the patchsets, can you
clarify please why this will have no effect at all ?
Andrey
+
+ unmap_mapping_range(bdev->dev_mapping, 0, 0 , 1);
+ /*TODO What about ttm_mem_io_free_vm(bo) ? */
+
+ for (i = TTM_NUM_MEM_TYPES - 1; i >= 0; i--) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_unlock(man);
+ }
+}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual_address_space);
int ttm_bo_wait(struct ttm_buffer_object *bo,
bool interruptible, bool no_wait)
diff --git a/include/drm/ttm/ttm_bo_driver.h
b/include/drm/ttm/ttm_bo_driver.h
index c9e0fd0..3133463 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -600,6 +600,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
*/
void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev);
+
/**
* ttm_bo_unmap_virtual
*
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Re: [PATCH 1/6] drm/ttm: Add unampping of the entire device address space
Am 09.05.20 um 20:51 schrieb Andrey Grodzovsky:
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c| 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
You should drop that it will just result in a deadlock warning for
Nouveau and has no effect at all.
Apart from that looks good to me,
Christian.
+
+ unmap_mapping_range(bdev->dev_mapping, 0, 0 , 1);
+ /*TODO What about ttm_mem_io_free_vm(bo) ? */
+
+ for (i = TTM_NUM_MEM_TYPES - 1; i >= 0; i--) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_unlock(man);
+ }
+}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual_address_space);
int ttm_bo_wait(struct ttm_buffer_object *bo,
bool interruptible, bool no_wait)
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index c9e0fd0..3133463 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -600,6 +600,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
*/
void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev);
+
/**
* ttm_bo_unmap_virtual
*
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[PATCH 1/6] drm/ttm: Add unampping of the entire device address space
Signed-off-by: Andrey Grodzovsky
---
drivers/gpu/drm/ttm/ttm_bo.c| 22 +-
include/drm/ttm/ttm_bo_driver.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index c5b516f..eae61cc 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1750,9 +1750,29 @@ void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
ttm_bo_unmap_virtual_locked(bo);
ttm_mem_io_unlock(man);
}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev)
+{
+ struct ttm_mem_type_manager *man;
+ int i;
-EXPORT_SYMBOL(ttm_bo_unmap_virtual);
+ for (i = 0; i < TTM_NUM_MEM_TYPES; i++) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_lock(man, false);
+ }
+
+ unmap_mapping_range(bdev->dev_mapping, 0, 0 , 1);
+ /*TODO What about ttm_mem_io_free_vm(bo) ? */
+
+ for (i = TTM_NUM_MEM_TYPES - 1; i >= 0; i--) {
+ man = >man[i];
+ if (man->has_type && man->use_type)
+ ttm_mem_io_unlock(man);
+ }
+}
+EXPORT_SYMBOL(ttm_bo_unmap_virtual_address_space);
int ttm_bo_wait(struct ttm_buffer_object *bo,
bool interruptible, bool no_wait)
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index c9e0fd0..3133463 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -600,6 +600,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
*/
void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
+void ttm_bo_unmap_virtual_address_space(struct ttm_bo_device *bdev);
+
/**
* ttm_bo_unmap_virtual
*
--
2.7.4
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