Forgot to add mm mailing list. Sorry.
This patch enables the amdkfd driver to retrieve the kfd_process
object from the process's mm_struct. This is needed because kfd_process
lifespan is bound to the process's mm_struct lifespan.
When amdkfd is notified about an mm_struct tear-down, it checks if the
kfd_process pointer is valid. If so, it releases the kfd_process object
and all relevant resources.
In v3 of the patchset I will update the binding to match the final discussions
on [PATCH 1/8] mmput: use notifier chain to call subsystem exit handler.
In the meantime, I'm going to try and see if I can drop the kfd_process
in mm_struct and remove the use of the new notification chain in mmput.
Instead, I will try to use the mmu release notifier.
Signed-off-by: Oded Gabbay <[email protected]>
---
include/linux/mm_types.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 678097c..ff71496 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -20,6 +20,10 @@
struct hmm;
#endif
+#if defined(CONFIG_HSA_RADEON) || defined(CONFIG_HSA_RADEON_MODULE)
+struct kfd_process;
+#endif
+
#ifndef AT_VECTOR_SIZE_ARCH
#define AT_VECTOR_SIZE_ARCH 0
#endif
@@ -439,6 +443,16 @@ struct mm_struct {
*/
struct hmm *hmm;
#endif
+#if defined(CONFIG_HSA_RADEON) || defined(CONFIG_HSA_RADEON_MODULE)
+ /*
+ * kfd always register an mmu_notifier we rely on mmu notifier to keep
+ * refcount on mm struct as well as forbiding registering kfd on a
+ * dying mm
+ *
+ * This field is set with mmap_sem old in write mode.
+ */
+ struct kfd_process *kfd_process;
+#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
pgtable_t pmd_huge_pte; /* protected by page_table_lock */
#endif
--
1.9.1
On Thu, Jul 17, 2014 at 04:57:58PM +0300, Oded Gabbay wrote:
> Forgot to add mm mailing list. Sorry.
>
> This patch enables the amdkfd driver to retrieve the kfd_process
> object from the process's mm_struct. This is needed because kfd_process
> lifespan is bound to the process's mm_struct lifespan.
>
> When amdkfd is notified about an mm_struct tear-down, it checks if the
> kfd_process pointer is valid. If so, it releases the kfd_process object
> and all relevant resources.
>
> In v3 of the patchset I will update the binding to match the final discussions
> on [PATCH 1/8] mmput: use notifier chain to call subsystem exit handler.
> In the meantime, I'm going to try and see if I can drop the kfd_process
> in mm_struct and remove the use of the new notification chain in mmput.
> Instead, I will try to use the mmu release notifier.
So the mmput notifier chain will not happen. I did a patch with call_srcu
and adding couple more helper to mmu_notifier. I will send that today for
review.
That being said, adding a device driver specific to mm_struct will most
likely be a big no. I am myself gonna remove hmm from mm_struct as people
are reluctant to see such change.
Cheers,
J?r?me
>
> Signed-off-by: Oded Gabbay <[email protected]>
> ---
> include/linux/mm_types.h | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 678097c..ff71496 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -20,6 +20,10 @@
> struct hmm;
> #endif
> +#if defined(CONFIG_HSA_RADEON) || defined(CONFIG_HSA_RADEON_MODULE)
> +struct kfd_process;
> +#endif
> +
> #ifndef AT_VECTOR_SIZE_ARCH
> #define AT_VECTOR_SIZE_ARCH 0
> #endif
> @@ -439,6 +443,16 @@ struct mm_struct {
> */
> struct hmm *hmm;
> #endif
> +#if defined(CONFIG_HSA_RADEON) || defined(CONFIG_HSA_RADEON_MODULE)
> + /*
> + * kfd always register an mmu_notifier we rely on mmu notifier to keep
> + * refcount on mm struct as well as forbiding registering kfd on a
> + * dying mm
> + *
> + * This field is set with mmap_sem old in write mode.
> + */
> + struct kfd_process *kfd_process;
> +#endif
> #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
> pgtable_t pmd_huge_pte; /* protected by page_table_lock */
> #endif
> --
> 1.9.1
>
On 17/07/14 17:12, Jerome Glisse wrote:
> On Thu, Jul 17, 2014 at 04:57:58PM +0300, Oded Gabbay wrote:
>> Forgot to add mm mailing list. Sorry.
>>
>> This patch enables the amdkfd driver to retrieve the kfd_process
>> object from the process's mm_struct. This is needed because kfd_process
>> lifespan is bound to the process's mm_struct lifespan.
>>
>> When amdkfd is notified about an mm_struct tear-down, it checks if the
>> kfd_process pointer is valid. If so, it releases the kfd_process object
>> and all relevant resources.
>>
>> In v3 of the patchset I will update the binding to match the final discussions
>> on [PATCH 1/8] mmput: use notifier chain to call subsystem exit handler.
>> In the meantime, I'm going to try and see if I can drop the kfd_process
>> in mm_struct and remove the use of the new notification chain in mmput.
>> Instead, I will try to use the mmu release notifier.
>
> So the mmput notifier chain will not happen. I did a patch with call_srcu
> and adding couple more helper to mmu_notifier. I will send that today for
> review.
>
> That being said, adding a device driver specific to mm_struct will most
> likely be a big no. I am myself gonna remove hmm from mm_struct as people
> are reluctant to see such change.
>
> Cheers,
> J?r?me
>
Yes, I followed that email thread and you can see that in the commit message I
referred to it (saying that in v3 of the patchset I'm also going to use
mmu_notifier). I will take your patch once you publish it and use it to change
amdkfd behavior.
Oded
>
>>
>> Signed-off-by: Oded Gabbay <[email protected]>
>> ---
>> include/linux/mm_types.h | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>>
>> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
>> index 678097c..ff71496 100644
>> --- a/include/linux/mm_types.h
>> +++ b/include/linux/mm_types.h
>> @@ -20,6 +20,10 @@
>> struct hmm;
>> #endif
>> +#if defined(CONFIG_HSA_RADEON) || defined(CONFIG_HSA_RADEON_MODULE)
>> +struct kfd_process;
>> +#endif
>> +
>> #ifndef AT_VECTOR_SIZE_ARCH
>> #define AT_VECTOR_SIZE_ARCH 0
>> #endif
>> @@ -439,6 +443,16 @@ struct mm_struct {
>> */
>> struct hmm *hmm;
>> #endif
>> +#if defined(CONFIG_HSA_RADEON) || defined(CONFIG_HSA_RADEON_MODULE)
>> + /*
>> + * kfd always register an mmu_notifier we rely on mmu notifier to keep
>> + * refcount on mm struct as well as forbiding registering kfd on a
>> + * dying mm
>> + *
>> + * This field is set with mmap_sem old in write mode.
>> + */
>> + struct kfd_process *kfd_process;
>> +#endif
>> #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
>> pgtable_t pmd_huge_pte; /* protected by page_table_lock */
>> #endif
>> --
>> 1.9.1
>>