Issue:
In the scenario where svm_range_restore_pages is called, but svm->checkpoint_ts
has not been set and the retry fault has not been drained, svm_range_unmap_from_cpu
is triggered and calls svm_range_free. Meanwhile, svm_range_restore_pages
continues execution and reaches svm_range_from_addr. This results in
a "failed to find prange..." error, causing the page recovery to fail.
How to fix:
Move the timestamp check code under the protection of svm->lock.
v2:
Make sure all right locks are released before go out.
v3:
Directly goto out_unlock_svms, and return -EAGAIN.
Signed-off-by: Emily Deng <Emily.Deng@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 34 ++++++++++++++++------------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index d04725583f19..42ee49d19ee9 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2917,10 +2917,13 @@ static bool svm_range_skip_recover(struct svm_range *prange)
static void
svm_range_count_fault(struct kfd_node *node, struct kfd_process *p,
- int32_t gpuidx)
+ int32_t gpuidx, int r)
{
struct kfd_process_device *pdd;
+ if (r == -EAGAIN)
+ return;
+
/* fault is on different page of same range
* or fault is skipped to recover later
* or fault is on invalid virtual address
@@ -3008,19 +3011,6 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
goto out;
}
- /* check if this page fault time stamp is before svms->checkpoint_ts */
- if (svms->checkpoint_ts[gpuidx] != 0) {
- if (amdgpu_ih_ts_after_or_equal(ts, svms->checkpoint_ts[gpuidx])) {
- pr_debug("draining retry fault, drop fault 0x%llx\n", addr);
- r = 0;
- goto out;
- } else
- /* ts is after svms->checkpoint_ts now, reset svms->checkpoint_ts
- * to zero to avoid following ts wrap around give wrong comparing
- */
- svms->checkpoint_ts[gpuidx] = 0;
- }
-
if (!p->xnack_enabled) {
pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
r = -EFAULT;
@@ -3040,6 +3030,20 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
mmap_read_lock(mm);
retry_write_locked:
mutex_lock(&svms->lock);
+
+ /* check if this page fault time stamp is before svms->checkpoint_ts */
+ if (svms->checkpoint_ts[gpuidx] != 0) {
+ if (amdgpu_ih_ts_after_or_equal(ts, svms->checkpoint_ts[gpuidx])) {
+ pr_debug("draining retry fault, drop fault 0x%llx\n", addr);
+ r = -EAGAIN;
+ goto out_unlock_svms;
+ } else
+ /* ts is after svms->checkpoint_ts now, reset svms->checkpoint_ts
+ * to zero to avoid following ts wrap around give wrong comparing
+ */
+ svms->checkpoint_ts[gpuidx] = 0;
+ }
+
prange = svm_range_from_addr(svms, addr, NULL);
if (!prange) {
pr_debug("failed to find prange svms 0x%p address [0x%llx]\n",
@@ -3165,7 +3169,7 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
mutex_unlock(&svms->lock);
mmap_read_unlock(mm);
- svm_range_count_fault(node, p, gpuidx);
+ svm_range_count_fault(node, p, gpuidx, r);
mmput(mm);
out:
--
2.34.1
