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    <div class="moz-cite-prefix">On 2024-04-17 23:14, Felix Kuehling
      wrote:<br>
    </div>
    <blockquote type="cite" cite="mid:20240418031410.2815452-1-felix.kuehling@amd.com">
      <pre class="moz-quote-pre" wrap="">Handle case that dma_fence_get_rcu_safe returns NULL.

If restore work is already scheduled, only update its timer. The same
work item cannot be queued twice, so undo the extra queue eviction.

Fixes: 9a1c1339abf9 ("drm/amdkfd: Run restore_workers on freezable WQs")
Signed-off-by: Felix Kuehling <a class="moz-txt-link-rfc2396E" href="mailto:felix.kuehling@amd.com"><felix.kuehling@amd.com></a></pre>
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    Reviewed-by: Philip Yang <a class="moz-txt-link-rfc2396E" href="mailto:Philip.Yang@amd.com"><Philip.Yang@amd.com></a><br>
    <blockquote type="cite" cite="mid:20240418031410.2815452-1-felix.kuehling@amd.com">
      <pre class="moz-quote-pre" wrap="">
---
 drivers/gpu/drm/amd/amdkfd/kfd_process.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index b79986412cd8..aafdf064651f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1922,6 +1922,8 @@ static int signal_eviction_fence(struct kfd_process *p)
        rcu_read_lock();
        ef = dma_fence_get_rcu_safe(&p->ef);
        rcu_read_unlock();
+       if (!ef)
+               return -EINVAL;
 
        ret = dma_fence_signal(ef);
        dma_fence_put(ef);
@@ -1949,10 +1951,9 @@ static void evict_process_worker(struct work_struct *work)
                 * they are responsible stopping the queues and scheduling
                 * the restore work.
                 */
-               if (!signal_eviction_fence(p))
-                       queue_delayed_work(kfd_restore_wq, &p->restore_work,
-                               msecs_to_jiffies(PROCESS_RESTORE_TIME_MS));
-               else
+               if (signal_eviction_fence(p) ||
+                   mod_delayed_work(kfd_restore_wq, &p->restore_work,
+                                    msecs_to_jiffies(PROCESS_RESTORE_TIME_MS)))
                        kfd_process_restore_queues(p);
 
                pr_debug("Finished evicting pasid 0x%x\n", p->pasid);
</pre>
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