Am 20.04.2017 um 05:10 schrieb zhoucm1:



On 2017年04月19日 17:40, Christian König wrote:
Am 19.04.2017 um 11:15 schrieb zhoucm1:


On 2017年04月19日 14:59, Christian König wrote:
Am 19.04.2017 um 08:52 schrieb zhoucm1:


On 2017年04月19日 14:38, Christian König wrote:
Am 19.04.2017 um 05:50 schrieb Chunming Zhou:
gtt_mgr_alloc is called by many places in local driver, while
gtt_mgr_new is called by get_node in ttm.

NAK, that can lead to over allocating the address space and we can't handle that during suspend/resume.
I didn't get your mean here.

Describe it first from my side, I found this issue on APU like carrizo, vram is little, so gtt is used much more, we always found the gtt cannot be used end up and results in Game failed to allocate memory, but from dumping mm hole table, there are many free hole and memory.

In this case you need to increase the gartsize parameter to the kernel module. What is the default size chosen for this? Maybe we need to adjust that default.

The root cause is mgr->available statistic is incorrect, which doesn't match dump mm table.

That's actually correct.
There will be a problem here, memory not mapped in mm table won't be able to evict by TTM.

Why do you think so? It's possible that we have a bug somewhere regarding this, but at least in theory that shouldn't be the case.
With more thinking and experiments, I think you're right, with my patch, gtt mgr will be able to stolen memory without right limitation so that game can allocate more than gtt size memory, so game can run. Will just increase gtt size to 3G by default, and add precise gtt print, some our script tool is basing on it.

Wait a second with that. I had more time thinking about it and you might indeed have stumbled over something:

1. In amdgpu_evict_flags() we set an upper limit to force directly allocation of the BO. 2. In amdgpu_gtt_mgr_alloc() we set the node start to AMDGPU_BO_INVALID_OFFSET if we don't map the BO into GART. 3. In amdgpu_ttm_bo_eviction_valuable() we check if the BO in the LRU matches the requested limit.

So what happens is that not mapped BOs are never evicted correctly when we run out of GART memory during eviction from VRAM!

Give me a second to hack a patch for this.

Regards,
Christian.


Thanks,
David Zhou


The root cause is here, we need to find a solution for it.

Yeah, that sounds like the handling is buggy somehow.

Regards,
Christian.

And yes, I agree your other opinions.

Regards,
David Zhou
We don't map all BOs in the GART domain into the actual GART table to avoid all the table operations.

I think mgr->available should only be changed when insert/free node.

No, on suspend/resume we need to be able to add all BOs into the GART table. So with your change suspend/resume can potentially fail.

Regards,
Christian.



Regards,
David Zhou

Regards,
Christian.


Change-Id: Ia5a18a3b531a01ad7d47f40e08f778e7b94c048a
Signed-off-by: Chunming Zhou <david1.z...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 11 +++++------
  1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
index 69ab2ee..8a950a5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
@@ -124,6 +124,8 @@ int amdgpu_gtt_mgr_alloc(struct ttm_mem_type_manager *man, r = drm_mm_insert_node_in_range_generic(&mgr->mm, node, mem->num_pages,
                          mem->page_alignment, 0,
                          fpfn, lpfn, sflags, aflags);
+    if (!r)
+        mgr->available -= mem->num_pages;
      spin_unlock(&mgr->lock);
        if (!r) {
@@ -160,7 +162,6 @@ static int amdgpu_gtt_mgr_new(struct ttm_mem_type_manager *man,
          spin_unlock(&mgr->lock);
          return 0;
      }
-    mgr->available -= mem->num_pages;
      spin_unlock(&mgr->lock);
        node = kzalloc(sizeof(*node), GFP_KERNEL);
@@ -187,9 +188,6 @@ static int amdgpu_gtt_mgr_new(struct ttm_mem_type_manager *man,
        return 0;
  err_out:
-    spin_lock(&mgr->lock);
-    mgr->available += mem->num_pages;
-    spin_unlock(&mgr->lock);
        return r;
  }
@@ -214,9 +212,10 @@ static void amdgpu_gtt_mgr_del(struct ttm_mem_type_manager *man,
          return;
        spin_lock(&mgr->lock);
-    if (node->start != AMDGPU_BO_INVALID_OFFSET)
+    if (node->start != AMDGPU_BO_INVALID_OFFSET) {
          drm_mm_remove_node(node);
-    mgr->available += mem->num_pages;
+        mgr->available += mem->num_pages;
+    }
      spin_unlock(&mgr->lock);
        kfree(node);



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