Am 2022-07-25 um 08:23 schrieb Philip Yang:
Giant svm range split to smaller ranges, align the range start address
to max svm range pages to improve MMU TLB usage.
Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 52 +++++++++++++++++++---------
1 file changed, 36 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index cf9565ddddf8..044bb99f88ea 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1885,6 +1885,37 @@ __init void svm_range_set_max_pages(struct amdgpu_device *adev)
max_svm_range_pages = ALIGN(max_svm_range_pages, 1ULL << 9);
}
+static int
+__svm_range_add(struct svm_range_list *svms, uint64_t start, uint64_t last,
+ struct list_head *insert_list, struct list_head *update_list)
It would be nice to find a better name for this. Maybe
svm_range_split_new. Maybe make the max size a parameter of the function
for better clarity.
+{
+ struct svm_range *prange;
+ uint64_t l;
+
+ pr_debug("max_svm_range_pages 0x%llx adding [0x%llx 0x%llx]\n",
+ max_svm_range_pages, start, last);
+
+ while (last >= start) {
+ if (last - start + 1 > max_svm_range_pages) {
Use a single READ_ONCE in this function to read max_svm_range_pages into
a local variable. This should avoid race conditions with GPU hotplug. If
you make the max size a parameter of this function, that also works if
the caller uses READ_ONCE.
+ if (start % max_svm_range_pages)
+ l = ALIGN(start, max_svm_range_pages) - 1;
+ else
+ l = start + max_svm_range_pages - 1;
+ } else {
+ l = last;
I think this whole if block could be written as
l = min(last, ALIGN_DOWN(start + max_svm_range_pages,
max_svm_range_pages) - 1);
Regards,
Felix
+ }
+
+ prange = svm_range_new(svms, start, l);
+ if (!prange)
+ return -ENOMEM;
+ list_add(&prange->list, insert_list);
+ list_add(&prange->update_list, update_list);
+
+ start = l + 1;
+ }
+ return 0;
+}
+
/**
* svm_range_add - add svm range and handle overlap
* @p: the range add to this process svms
@@ -1987,14 +2018,10 @@ svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
/* insert a new node if needed */
if (node->start > start) {
- prange = svm_range_new(svms, start, node->start - 1);
- if (!prange) {
- r = -ENOMEM;
+ r = __svm_range_add(svms, start, node->start - 1,
+ insert_list, update_list);
+ if (r)
goto out;
- }
-
- list_add(&prange->list, insert_list);
- list_add(&prange->update_list, update_list);
}
node = next;
@@ -2002,15 +2029,8 @@ svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
}
/* add a final range at the end if needed */
- if (start <= last) {
- prange = svm_range_new(svms, start, last);
- if (!prange) {
- r = -ENOMEM;
- goto out;
- }
- list_add(&prange->list, insert_list);
- list_add(&prange->update_list, update_list);
- }
+ if (start <= last)
+ r = __svm_range_add(svms, start, last, insert_list, update_list);
out:
if (r)
