search for: hmm_mirror

...pace mirroring implementation and API Address space mirroring's main objective is to allow duplication of a range of CPU page table into a device page table; HMM helps keep both synchronized. A device driver that wants to mirror a process address space must start with the -registration of an hmm_mirror struct:: - - int hmm_mirror_register(struct hmm_mirror *mirror, - struct mm_struct *mm); - -The mirror struct has a set of callbacks that are used -to propagate CPU page tables:: - - struct hmm_mirror_ops { - /* release() - release hmm_mirror - * - * @mirror: p...

Make HMM_MIRROR an option that is selected by drivers wanting to use it instead of a user visible option as it is just a low-level implementation detail. Signed-off-by: Christoph Hellwig <hch at lst.de> --- drivers/gpu/drm/amd/amdgpu/Kconfig | 4 +++- drivers/gpu/drm/nouveau/Kconfig | 4 +++- mm/Kconf...

The migrate_vma helper is only used by noveau to migrate device private pages around. Other HMM_MIRROR users like amdgpu or infiniband don't need it. Signed-off-by: Christoph Hellwig <hch at lst.de> --- drivers/gpu/drm/nouveau/Kconfig | 1 + mm/Kconfig | 1 - 2 files changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/dr...

On 6/13/19 2:43 AM, Christoph Hellwig wrote: > The migrate_vma helper is only used by noveau to migrate device private > pages around. Other HMM_MIRROR users like amdgpu or infiniband don't > need it. > > Signed-off-by: Christoph Hellwig <hch at lst.de> > --- > drivers/gpu/drm/nouveau/Kconfig | 1 + > mm/Kconfig | 1 - > 2 files changed, 1 insertion(+), 1 deletion(-) > > diff --git a/dri...

From: Jason Gunthorpe <jgg at mellanox.com> Only the function calls are stubbed out with static inlines that always fail. This is the standard way to write a header for an optional component and makes it easier for drivers that only optionally need HMM_MIRROR. Reviewed-by: J?r?me Glisse <jglisse at redhat.com> Tested-by: Ralph Campbell <rcampbell at nvidia.com> Signed-off-by: Jason Gunthorpe <jgg at mellanox.com> --- include/linux/hmm.h | 59 ++++++++++++++++++++++++++++++++++++--------- kernel/fork.c | 1 - 2 files changed, 4...

...ncies. Signed-off-by: Christoph Hellwig <hch at lst.de> --- mm/Kconfig | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/Kconfig b/mm/Kconfig index 56cec636a1fc..b18782be969c 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -677,8 +677,7 @@ config DEV_PAGEMAP_OPS config HMM_MIRROR bool "HMM mirror CPU page table into a device page table" - depends on (X86_64 || PPC64) - depends on MMU && 64BIT + depends on MMU select MMU_NOTIFIER help Select HMM_MIRROR if you want to mirror range of the CPU page table of a -- 2.20.1

From: Jason Gunthorpe <jgg at mellanox.com> hmm_mirror's handling of ranges does not use a sequence count which results in this bug: CPU0 CPU1 hmm_range_wait_until_valid(range) valid == true...

...rb_root, it.rb) { > - list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) { > - bo->mn = NULL; > - list_del_init(&bo->mn_list); > - } > - kfree(node); > - } > - up_write(&amn->lock); > - mutex_unlock(&adev->mn_lock); > - > - hmm_mirror_unregister(&amn->mirror); > - kfree(amn); > -} > - > -/** > - * amdgpu_hmm_mirror_release - callback to notify about mm destruction > - * > - * @mirror: the HMM mirror (mm) this callback is about > - * > - * Shedule a work item to lazy destroy HMM mirror. > - */...

From: Jason Gunthorpe <jgg at mellanox.com> Remove the hmm_mirror object and use the mmu_range_notifier API instead for the range, and use the normal mmu_notifier API for the general invalidation callback. While here re-organize the pagefault path so the locking pattern is clear. nouveau is the only driver that uses a temporary range object and instead forwards...

From: Jason Gunthorpe <jgg at mellanox.com> There is no reason to get the invalidate_range_start() callback via an indirection through hmm_mirror, just register a normal notifier directly. Cc: Ben Skeggs <bskeggs at redhat.com> Cc: dri-devel at lists.freedesktop.org Cc: nouveau at lists.freedesktop.org Cc: Ralph Campbell <rcampbell at nvidia.com> Signed-off-by: Jason Gunthorpe <jgg at mellanox.com> --- drivers/gpu/drm/nou...

On Tue, Jul 30, 2019 at 08:52:03AM +0300, Christoph Hellwig wrote: > There isn't really any architecture specific code in this page table > walk implementation, so drop the dependencies. > > Signed-off-by: Christoph Hellwig <hch at lst.de> > mm/Kconfig | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) Happy to see it, lets try to get this patch + the required

On Tue, Jul 30, 2019 at 03:03:46PM -0300, Jason Gunthorpe wrote: > On Tue, Jul 30, 2019 at 08:52:03AM +0300, Christoph Hellwig wrote: > > There isn't really any architecture specific code in this page table > > walk implementation, so drop the dependencies. > > > > Signed-off-by: Christoph Hellwig <hch at lst.de> > > mm/Kconfig | 3 +-- > > 1 file

On Fri, Nov 01, 2019 at 03:59:26PM +0000, Yang, Philip wrote: > > This test for range_blockable should be before mutex_lock, I can move > > it up > > > yes, thanks. Okay, I wrote it like this: if (mmu_notifier_range_blockable(range)) mutex_lock(&adev->notifier_lock); else if (!mutex_trylock(&adev->notifier_lock)) return false; > > Also, do you

On Fri, Nov 01, 2019 at 02:44:51PM +0000, Yang, Philip wrote: > @@ -854,12 +853,20 @@ int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages) > r = -EPERM; > goto out_unlock; > } > + up_read(&mm->mmap_sem); > + timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); > + > +retry: > + range->notifier_seq =

On 2019-10-29 3:25 p.m., Jason Gunthorpe wrote: > On Tue, Oct 29, 2019 at 07:22:37PM +0000, Yang, Philip wrote: >> Hi Jason, >> >> I did quick test after merging amd-staging-drm-next with the >> mmu_notifier branch, which includes this set changes. The test result >> has different failures, app stuck intermittently, GUI no display etc. I >> am understanding

...he collision-retry lock around hmm_range_fault to use the one now > provided by the mmu_range notifier. > > Although this driver does not seem to use the collision retry lock that > hmm provides correctly, it can still be converted over to use the > mmu_range_notifier api instead of hmm_mirror without too much trouble. > > This also deletes another place where a driver is associating additional > data (struct amdgpu_mn) with a mmu_struct. > > Cc: Alex Deucher <alexander.deucher at amd.com> > Cc: Christian K?nig <christian.koenig at amd.com> > Cc: David...

...rb_root, it.rb) { > - list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) { > - bo->mn = NULL; > - list_del_init(&bo->mn_list); > - } > - kfree(node); > - } > - up_write(&amn->lock); > - mutex_unlock(&adev->mn_lock); > - > - hmm_mirror_unregister(&amn->mirror); > - kfree(amn); > -} > - > -/** > - * amdgpu_hmm_mirror_release - callback to notify about mm destruction > - * > - * @mirror: the HMM mirror (mm) this callback is about > - * > - * Shedule a work item to lazy destroy HMM mirror. > - */...

...llanox.com> Convert the collision-retry lock around hmm_range_fault to use the one now provided by the mmu_range notifier. Although this driver does not seem to use the collision retry lock that hmm provides correctly, it can still be converted over to use the mmu_range_notifier api instead of hmm_mirror without too much trouble. This also deletes another place where a driver is associating additional data (struct amdgpu_mn) with a mmu_struct. Cc: Alex Deucher <alexander.deucher at amd.com> Cc: Christian K?nig <christian.koenig at amd.com> Cc: David (ChunMing) Zhou <David1.Zhou at...

...gt; bugs and poor implementation. This is a result of the complexity in how > the notifier interacts with get_user_pages(). It is extremely difficult to > use it correctly. > > Consolidate all of this code together into the core mmu_notifier and > provide a locking scheme similar to hmm_mirror that allows the user to > safely use get_user_pages() and reliably know if the page list still > matches the mm. > > This new arrangment plays nicely with the !blockable mode for > OOM. Scanning the interval tree is done such that the intersection test > will always succeed, and...

....com> Convert the collision-retry lock around hmm_range_fault to use the one now provided by the mmu_interval notifier. Although this driver does not seem to use the collision retry lock that hmm provides correctly, it can still be converted over to use the mmu_interval_notifier api instead of hmm_mirror without too much trouble. This also deletes another place where a driver is associating additional data (struct amdgpu_mn) with a mmu_struct. Signed-off-by: Philip Yang <Philip.Yang at amd.com> Reviewed-by: Philip Yang <Philip.Yang at amd.com> Tested-by: Philip Yang <Philip.Yang at...