On 2023-10-19 16:05, Felix Kuehling
wrote:
On 2023-10-18 18:26, Alex Sierra wrote:
Split SVM ranges that have been mapped into 2MB page table entries,
require to be remap in case the split has happened in a non-aligned
VA.
[WHY]:
This condition causes the 2MB page table entries be split into 4KB
PTEs.
Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 45 +++++++++++++++++++++-------
1 file changed, 34 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 7b81233bc9ae..1dd9a1cf2358 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1104,26 +1104,34 @@ svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last,
}
static int
-svm_range_split_tail(struct svm_range *prange,
- uint64_t new_last, struct list_head *insert_list)
+svm_range_split_tail(struct svm_range *prange, uint64_t new_last,
+ struct list_head *insert_list, struct list_head *remap_list)
{
struct svm_range *tail;
int r = svm_range_split(prange, prange->start, new_last, &tail);
- if (!r)
+ if (!r) {
list_add(&tail->list, insert_list);
+ if (!IS_ALIGNED(tail->last + 1 - tail->start,
+ 1UL << tail->granularity))
I'm not sure about this condition. I thought this condition should be about the point where the range is split, not the size of it. So my understanding is that this should be
if (!IS_ALIGNED(new_last+1, 1UL << prange->granularity))
I think prange->granularity is not always 9, 512 pages, we
should check the original prange size is larger than 512.
if (!IS_ALIGNED(new_last + 1, 512) &&
tail->last - prange->start >= 512)
+ list_add(&tail->update_list, remap_list);
+ }
return r;
}
static int
-svm_range_split_head(struct svm_range *prange,
- uint64_t new_start, struct list_head *insert_list)
+svm_range_split_head(struct svm_range *prange, uint64_t new_start,
+ struct list_head *insert_list, struct list_head *remap_list)
{
struct svm_range *head;
int r = svm_range_split(prange, new_start, prange->last, &head);
- if (!r)
+ if (!r) {
list_add(&head->list, insert_list);
+ if (!IS_ALIGNED(head->last + 1 - head->start,
+ 1UL << head->granularity))
Similar as above.
if (!IS_ALIGNED(new_start, 1UL << prange->granularity))
if (!IS_ALIGNED(new_start, 512) && prange->last - head->start >= 512)
Regards,
Felix
+ list_add(&head->update_list, remap_list);
+ }
return r;
}
@@ -2113,7 +2121,7 @@ static int
svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
struct list_head *update_list, struct list_head *insert_list,
- struct list_head *remove_list)
+ struct list_head *remove_list, struct list_head *remap_list)
{
unsigned long last = start + size - 1UL;
struct svm_range_list *svms = &p->svms;
@@ -2129,6 +2137,7 @@ svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
INIT_LIST_HEAD(insert_list);
INIT_LIST_HEAD(remove_list);
INIT_LIST_HEAD(&new_list);
+ INIT_LIST_HEAD(remap_list);
node = interval_tree_iter_first(&svms->objects, start, last);
while (node) {
@@ -2153,6 +2162,7 @@ svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
struct svm_range *old = prange;
prange = svm_range_clone(old);
+
unnecessary change.
Regards,
Philip
if (!prange) {
r = -ENOMEM;
goto out;
@@ -2161,18 +2171,17 @@ svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
list_add(&old->update_list, remove_list);
list_add(&prange->list, insert_list);
list_add(&prange->update_list, update_list);
-
if (node->start < start) {
pr_debug("change old range start\n");
r = svm_range_split_head(prange, start,
- insert_list);
+ insert_list, remap_list);
if (r)
goto out;
}
if (node->last > last) {
pr_debug("change old range last\n");
r = svm_range_split_tail(prange, last,
- insert_list);
+ insert_list, remap_list);
if (r)
goto out;
}
@@ -3565,6 +3574,7 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
struct list_head update_list;
struct list_head insert_list;
struct list_head remove_list;
+ struct list_head remap_list;
struct svm_range_list *svms;
struct svm_range *prange;
struct svm_range *next;
@@ -3596,7 +3606,7 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
/* Add new range and split existing ranges as needed */
r = svm_range_add(p, start, size, nattr, attrs, &update_list,
- &insert_list, &remove_list);
+ &insert_list, &remove_list, &remap_list);
if (r) {
mutex_unlock(&svms->lock);
mmap_write_unlock(mm);
@@ -3661,6 +3671,19 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
ret = r;
}
+ list_for_each_entry(prange, &remap_list, update_list) {
+ pr_debug("Remapping prange 0x%p [0x%lx 0x%lx]\n",
+ prange, prange->start, prange->last);
+ mutex_lock(&prange->migrate_mutex);
+ r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
+ true, true, prange->mapped_to_gpu);
+ if (r)
+ pr_debug("failed %d on remap svm range\n", r);
+ mutex_unlock(&prange->migrate_mutex);
+ if (r)
+ ret = r;
+ }
+
dynamic_svm_range_dump(svms);
mutex_unlock(&svms->lock);
