[PATCH] drm/amdkfd: Use partial hmm page walk during buffer validation in SVM
Xiaogang.Chen
xiaogang.chen at amd.com
Mon Dec 4 15:09:32 UTC 2023
From: Xiaogang Chen <xiaogang.chen at amd.com>
SVM uses hmm page walk to valid buffer before map to gpu vm. After have partial
migration/mapping do validation on same vm range as migration/map do instead of
whole svm range that can be very large. This change is expected to improve svm
code performance.
Signed-off-by: Xiaogang Chen<Xiaogang.Chen at amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 123 +++++++++++++++++++--------
1 file changed, 89 insertions(+), 34 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 2834fb351818..f670d5f6bcdf 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -158,13 +158,12 @@ svm_is_valid_dma_mapping_addr(struct device *dev, dma_addr_t dma_addr)
static int
svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
unsigned long offset, unsigned long npages,
- unsigned long *hmm_pfns, uint32_t gpuidx, uint64_t *vram_pages)
+ unsigned long *hmm_pfns, uint32_t gpuidx)
{
enum dma_data_direction dir = DMA_BIDIRECTIONAL;
dma_addr_t *addr = prange->dma_addr[gpuidx];
struct device *dev = adev->dev;
struct page *page;
- uint64_t vram_pages_dev;
int i, r;
if (!addr) {
@@ -174,7 +173,6 @@ svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
prange->dma_addr[gpuidx] = addr;
}
- vram_pages_dev = 0;
addr += offset;
for (i = 0; i < npages; i++) {
if (svm_is_valid_dma_mapping_addr(dev, addr[i]))
@@ -184,7 +182,6 @@ svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
if (is_zone_device_page(page)) {
struct amdgpu_device *bo_adev = prange->svm_bo->node->adev;
- vram_pages_dev++;
addr[i] = (hmm_pfns[i] << PAGE_SHIFT) +
bo_adev->vm_manager.vram_base_offset -
bo_adev->kfd.pgmap.range.start;
@@ -201,14 +198,14 @@ svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
pr_debug_ratelimited("dma mapping 0x%llx for page addr 0x%lx\n",
addr[i] >> PAGE_SHIFT, page_to_pfn(page));
}
- *vram_pages = vram_pages_dev;
+
return 0;
}
static int
svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
unsigned long offset, unsigned long npages,
- unsigned long *hmm_pfns, uint64_t *vram_pages)
+ unsigned long *hmm_pfns)
{
struct kfd_process *p;
uint32_t gpuidx;
@@ -227,7 +224,7 @@ svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
}
r = svm_range_dma_map_dev(pdd->dev->adev, prange, offset, npages,
- hmm_pfns, gpuidx, vram_pages);
+ hmm_pfns, gpuidx);
if (r)
break;
}
@@ -982,11 +979,6 @@ svm_range_split_nodes(struct svm_range *new, struct svm_range *old,
new->svm_bo = svm_range_bo_ref(old->svm_bo);
new->ttm_res = old->ttm_res;
- /* set new's vram_pages as old range's now, the acurate vram_pages
- * will be updated during mapping
- */
- new->vram_pages = min(old->vram_pages, new->npages);
-
spin_lock(&new->svm_bo->list_lock);
list_add(&new->svm_bo_list, &new->svm_bo->range_list);
spin_unlock(&new->svm_bo->list_lock);
@@ -1573,7 +1565,6 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
struct svm_validate_context *ctx;
unsigned long start, end, addr;
struct kfd_process *p;
- uint64_t vram_pages;
void *owner;
int32_t idx;
int r = 0;
@@ -1642,15 +1633,13 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
}
}
- vram_pages = 0;
- start = prange->start << PAGE_SHIFT;
- end = (prange->last + 1) << PAGE_SHIFT;
+ start = map_start << PAGE_SHIFT;
+ end = (map_last + 1) << PAGE_SHIFT;
for (addr = start; !r && addr < end; ) {
struct hmm_range *hmm_range;
unsigned long map_start_vma;
unsigned long map_last_vma;
struct vm_area_struct *vma;
- uint64_t vram_pages_vma;
unsigned long next = 0;
unsigned long offset;
unsigned long npages;
@@ -1677,13 +1666,11 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
}
if (!r) {
- offset = (addr - start) >> PAGE_SHIFT;
+ offset = (addr - (prange->start << PAGE_SHIFT)) >> PAGE_SHIFT;
r = svm_range_dma_map(prange, ctx->bitmap, offset, npages,
- hmm_range->hmm_pfns, &vram_pages_vma);
+ hmm_range->hmm_pfns);
if (r)
pr_debug("failed %d to dma map range\n", r);
- else
- vram_pages += vram_pages_vma;
}
svm_range_lock(prange);
@@ -1716,19 +1703,6 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
addr = next;
}
- if (addr == end) {
- prange->vram_pages = vram_pages;
-
- /* if prange does not include any vram page and it
- * has not released svm_bo drop its svm_bo reference
- * and set its actaul_loc to sys ram
- */
- if (!vram_pages && prange->ttm_res) {
- prange->actual_loc = 0;
- svm_range_vram_node_free(prange);
- }
- }
-
svm_range_unreserve_bos(ctx);
if (!r)
prange->validate_timestamp = ktime_get_boottime();
@@ -3516,6 +3490,81 @@ static void svm_range_evict_svm_bo_worker(struct work_struct *work)
svm_range_bo_unref(svm_bo);
}
+static int
+svm_range_vram_pages(struct svm_range *prange)
+{
+ unsigned long start, end, addr;
+ struct svm_range_list *svms;
+ struct kfd_process *p;
+ struct mm_struct *mm;
+ struct page *page;
+ int32_t gpuidx;
+ void *owner;
+ int r = 0;
+
+ prange->vram_pages = 0;
+ svms = prange->svms;
+ p = container_of(svms, struct kfd_process, svms);
+ mm = get_task_mm(p->lead_thread);
+ if (!mm) {
+ pr_debug("svms 0x%p process mm gone\n", svms);
+ return -ESRCH;
+ }
+
+ /* prange->actual_loc should not be 0 here */
+ gpuidx = kfd_process_gpuidx_from_gpuid(p, prange->actual_loc);
+ if (gpuidx < 0) {
+ pr_debug("failed get device by id 0x%x\n", prange->actual_loc);
+ return -EINVAL;
+ }
+ owner = kfd_svm_page_owner(p, gpuidx);
+
+ start = prange->start << PAGE_SHIFT;
+ end = (prange->last + 1) << PAGE_SHIFT;
+ for (addr = start; addr < end; ) {
+ struct hmm_range *hmm_range;
+ struct vm_area_struct *vma;
+ unsigned long next = 0;
+ unsigned long npages;
+ bool readonly;
+
+ vma = vma_lookup(mm, addr);
+ if (!vma) {
+ mmput(mm);
+ return -EFAULT;
+ }
+
+ readonly = !(vma->vm_flags & VM_WRITE);
+ next = min(vma->vm_end, end);
+ npages = (next - addr) >> PAGE_SHIFT;
+ r = amdgpu_hmm_range_get_pages(&prange->notifier, addr, npages,
+ readonly, owner, NULL,
+ &hmm_range);
+ if (r) {
+ pr_debug("failed %d to get svm range pages\n", r);
+ mmput(mm);
+ return r;
+ }
+
+ for (int i = 0; i < npages; i++) {
+ page = hmm_pfn_to_page(hmm_range->hmm_pfns[i]);
+ if (is_zone_device_page(page))
+ prange->vram_pages++;
+ }
+
+ if (amdgpu_hmm_range_get_pages_done(hmm_range)) {
+ pr_debug("hmm update the range, need validate again\n");
+ mmput(mm);
+ return -EAGAIN;
+ }
+
+ addr = next;
+ }
+
+ mmput(mm);
+ return 0;
+}
+
static int
svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
uint64_t start, uint64_t size, uint32_t nattr,
@@ -3567,6 +3616,12 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
list_for_each_entry_safe(prange, next, &insert_list, list) {
svm_range_add_to_svms(prange);
svm_range_add_notifier_locked(mm, prange);
+ /* cal each inserted pragen vram_pages */
+ if (prange->actual_loc && prange->ttm_res) {
+ r = svm_range_vram_pages(prange);
+ if (r)
+ return r;
+ }
}
list_for_each_entry(prange, &update_list, update_list) {
svm_range_apply_attrs(p, prange, nattr, attrs, &update_mapping);
--
2.25.1
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