Re: [PATCH v7 3/3] drm/buddy: Add defragmentation support

2024-03-04 Thread Matthew Auld 

On 04/03/2024 12:22, Paneer Selvam, Arunpravin wrote:

Hi Matthew,

On 2/22/2024 12:12 AM, Matthew Auld wrote:

On 21/02/2024 12:18, Arunpravin Paneer Selvam wrote:

Add a function to support defragmentation.

v1:
   - Defragment the memory beginning from min_order
 till the required memory space is available.

v2(Matthew):
   - add amdgpu user for defragmentation
   - add a warning if the two blocks are incompatible on
 defragmentation
   - call full defragmentation in the fini() function
   - place a condition to test if min_order is equal to 0
   - replace the list with safe_reverse() variant as we might
 remove the block from the list.

Signed-off-by: Arunpravin Paneer Selvam 


Suggested-by: Matthew Auld 
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 +++-
  drivers/gpu/drm/drm_buddy.c  | 93 +---
  include/drm/drm_buddy.h  |  3 +
  3 files changed, 97 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c

index e494f5bf136a..cff8a526c622 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -533,8 +533,21 @@ static int amdgpu_vram_mgr_new(struct 
ttm_resource_manager *man,

 min_block_size,
 >blocks,
 vres->flags);
-    if (unlikely(r))
-    goto error_free_blocks;
+    if (unlikely(r)) {
+    if (r == -ENOSPC) {
+    drm_buddy_defrag(mm, min_block_size);
+    r = drm_buddy_alloc_blocks(mm, fpfn,
+   lpfn,
+   size,
+   min_block_size,
+   >blocks,
+   vres->flags);
+    if (unlikely(r))
+    goto error_free_blocks;
+    } else {
+    goto error_free_blocks;
+    }
+    }
    if (size > remaining_size)
  remaining_size = 0;
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 18e004fa39d3..56bd1560fbcd 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -203,6 +203,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
  drm_block_free(mm, mm->roots[i]);
  }
  +    drm_buddy_defrag(mm, mm->chunk_size << mm->max_order);


I think this needs to be called higher up, otherwise we blow up with 
the WARN, plus we just freed the root(s). There is also the case with 
non-power-of-two VRAM size, in which case you get multiple roots and 
max_order is just the largest root and not entire address space. I 
guess do this in the loop above and use the root order instead?


Also this should be done as part of the first patch and then in this 
patch it is just a case of exporting it. Every commit should ideally 
be functional by itself.
You mean we move the above change in drm_buddy_fini function and 
drm_buddy_defrag function as part of first patch.
And just we add export function and add amdgpu user in this patch. Is my 
understanding correct?


Yeah, I think that makes sense.



Thanks,
Arun.



+
  WARN_ON(mm->avail != mm->size);
    kfree(mm->roots);
@@ -276,25 +278,39 @@ drm_get_buddy(struct drm_buddy_block *block)
  }
  EXPORT_SYMBOL(drm_get_buddy);
  -static void __drm_buddy_free(struct drm_buddy *mm,
- struct drm_buddy_block *block)
+static unsigned int __drm_buddy_free(struct drm_buddy *mm,
+ struct drm_buddy_block *block,
+ bool defrag)
  {
+    unsigned int order, block_order;
  struct drm_buddy_block *parent;
  +    block_order = drm_buddy_block_order(block);
+
  while ((parent = block->parent)) {
-    struct drm_buddy_block *buddy;
+    struct drm_buddy_block *buddy = NULL;
    buddy = __get_buddy(block);
    if (!drm_buddy_block_is_free(buddy))
  break;
  -    if (drm_buddy_block_is_clear(block) !=
-    drm_buddy_block_is_clear(buddy))
-    break;
+    if (!defrag) {
+    /*
+ * Check the block and its buddy clear state and exit
+ * the loop if they both have the dissimilar state.
+ */
+    if (drm_buddy_block_is_clear(block) !=
+    drm_buddy_block_is_clear(buddy))
+    break;
  -    if (drm_buddy_block_is_clear(block))
-    mark_cleared(parent);
+    if (drm_buddy_block_is_clear(block))
+    mark_cleared(parent);
+    }
+
+    WARN_ON(defrag &&
+    (drm_buddy_block_is_clear(block) ==
+ drm_buddy_block_is_clear(buddy)));
    list_del(>link);
  @@ -304,8 +320,57 @@ static void __drm_buddy_free(struct drm_buddy 
*mm,

  block = parent;
  }
  -    mark_free(mm, block);
+    order = drm_buddy_block_order(block);
+    if

Re: [PATCH v7 3/3] drm/buddy: Add defragmentation support

2024-03-04 Thread Paneer Selvam, Arunpravin 

Hi Matthew,

On 2/22/2024 12:12 AM, Matthew Auld wrote:

On 21/02/2024 12:18, Arunpravin Paneer Selvam wrote:

Add a function to support defragmentation.

v1:
   - Defragment the memory beginning from min_order
 till the required memory space is available.

v2(Matthew):
   - add amdgpu user for defragmentation
   - add a warning if the two blocks are incompatible on
 defragmentation
   - call full defragmentation in the fini() function
   - place a condition to test if min_order is equal to 0
   - replace the list with safe_reverse() variant as we might
 remove the block from the list.

Signed-off-by: Arunpravin Paneer Selvam 


Suggested-by: Matthew Auld 
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 +++-
  drivers/gpu/drm/drm_buddy.c  | 93 +---
  include/drm/drm_buddy.h  |  3 +
  3 files changed, 97 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c

index e494f5bf136a..cff8a526c622 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -533,8 +533,21 @@ static int amdgpu_vram_mgr_new(struct 
ttm_resource_manager *man,

 min_block_size,
 >blocks,
 vres->flags);
-    if (unlikely(r))
-    goto error_free_blocks;
+    if (unlikely(r)) {
+    if (r == -ENOSPC) {
+    drm_buddy_defrag(mm, min_block_size);
+    r = drm_buddy_alloc_blocks(mm, fpfn,
+   lpfn,
+   size,
+   min_block_size,
+   >blocks,
+   vres->flags);
+    if (unlikely(r))
+    goto error_free_blocks;
+    } else {
+    goto error_free_blocks;
+    }
+    }
    if (size > remaining_size)
  remaining_size = 0;
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 18e004fa39d3..56bd1560fbcd 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -203,6 +203,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
  drm_block_free(mm, mm->roots[i]);
  }
  +    drm_buddy_defrag(mm, mm->chunk_size << mm->max_order);


I think this needs to be called higher up, otherwise we blow up with 
the WARN, plus we just freed the root(s). There is also the case with 
non-power-of-two VRAM size, in which case you get multiple roots and 
max_order is just the largest root and not entire address space. I 
guess do this in the loop above and use the root order instead?


Also this should be done as part of the first patch and then in this 
patch it is just a case of exporting it. Every commit should ideally 
be functional by itself.
You mean we move the above change in drm_buddy_fini function and 
drm_buddy_defrag function as part of first patch.
And just we add export function and add amdgpu user in this patch. Is my 
understanding correct?


Thanks,
Arun.



+
  WARN_ON(mm->avail != mm->size);
    kfree(mm->roots);
@@ -276,25 +278,39 @@ drm_get_buddy(struct drm_buddy_block *block)
  }
  EXPORT_SYMBOL(drm_get_buddy);
  -static void __drm_buddy_free(struct drm_buddy *mm,
- struct drm_buddy_block *block)
+static unsigned int __drm_buddy_free(struct drm_buddy *mm,
+ struct drm_buddy_block *block,
+ bool defrag)
  {
+    unsigned int order, block_order;
  struct drm_buddy_block *parent;
  +    block_order = drm_buddy_block_order(block);
+
  while ((parent = block->parent)) {
-    struct drm_buddy_block *buddy;
+    struct drm_buddy_block *buddy = NULL;
    buddy = __get_buddy(block);
    if (!drm_buddy_block_is_free(buddy))
  break;
  -    if (drm_buddy_block_is_clear(block) !=
-    drm_buddy_block_is_clear(buddy))
-    break;
+    if (!defrag) {
+    /*
+ * Check the block and its buddy clear state and exit
+ * the loop if they both have the dissimilar state.
+ */
+    if (drm_buddy_block_is_clear(block) !=
+    drm_buddy_block_is_clear(buddy))
+    break;
  -    if (drm_buddy_block_is_clear(block))
-    mark_cleared(parent);
+    if (drm_buddy_block_is_clear(block))
+    mark_cleared(parent);
+    }
+
+    WARN_ON(defrag &&
+    (drm_buddy_block_is_clear(block) ==
+ drm_buddy_block_is_clear(buddy)));
    list_del(>link);
  @@ -304,8 +320,57 @@ static void __drm_buddy_free(struct drm_buddy 
*mm,

  block = parent;
  }
  -    mark_free(mm, block);
+    order = drm_buddy_block_order(block);
+    if (block_order != order)
+    mark_free(mm, block);
+
+    return order;
+}
+
+/**
+ *

Re: [PATCH v7 3/3] drm/buddy: Add defragmentation support

2024-02-22 Thread Arunpravin Paneer Selvam 

Hi Christian,

On 2/21/2024 7:58 PM, Christian König wrote:

Am 21.02.24 um 13:18 schrieb Arunpravin Paneer Selvam:

Add a function to support defragmentation.


Thinking more about it maybe you want to call this function differently.

Essentially we are force merging pages even if their cleared flag 
doesn't match, that is something different than defragmentation I think.


Maybe rename it for force_merge or something similar. Not mandatory, 
just an idea how to improve the readability of the code.


Apart from that just let me know when I can push it to drm-misc-next.

Christian.
I am fixing few issues reported by user and addressing Matthew's 
suggestions on v7 version. I will post the v8 version incorporating

all the changes. I hope we can push v8 into drm-misc-next.

Thanks,
Arun.




v1:
   - Defragment the memory beginning from min_order
 till the required memory space is available.

v2(Matthew):
   - add amdgpu user for defragmentation
   - add a warning if the two blocks are incompatible on
 defragmentation
   - call full defragmentation in the fini() function
   - place a condition to test if min_order is equal to 0
   - replace the list with safe_reverse() variant as we might
 remove the block from the list.

Signed-off-by: Arunpravin Paneer Selvam 


Suggested-by: Matthew Auld 
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 +++-
  drivers/gpu/drm/drm_buddy.c  | 93 +---
  include/drm/drm_buddy.h  |  3 +
  3 files changed, 97 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c

index e494f5bf136a..cff8a526c622 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -533,8 +533,21 @@ static int amdgpu_vram_mgr_new(struct 
ttm_resource_manager *man,

 min_block_size,
 >blocks,
 vres->flags);
-    if (unlikely(r))
-    goto error_free_blocks;
+    if (unlikely(r)) {
+    if (r == -ENOSPC) {
+    drm_buddy_defrag(mm, min_block_size);
+    r = drm_buddy_alloc_blocks(mm, fpfn,
+   lpfn,
+   size,
+   min_block_size,
+   >blocks,
+   vres->flags);
+    if (unlikely(r))
+    goto error_free_blocks;
+    } else {
+    goto error_free_blocks;
+    }
+    }
    if (size > remaining_size)
  remaining_size = 0;
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 18e004fa39d3..56bd1560fbcd 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -203,6 +203,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
  drm_block_free(mm, mm->roots[i]);
  }
  +    drm_buddy_defrag(mm, mm->chunk_size << mm->max_order);
+
  WARN_ON(mm->avail != mm->size);
    kfree(mm->roots);
@@ -276,25 +278,39 @@ drm_get_buddy(struct drm_buddy_block *block)
  }
  EXPORT_SYMBOL(drm_get_buddy);
  -static void __drm_buddy_free(struct drm_buddy *mm,
- struct drm_buddy_block *block)
+static unsigned int __drm_buddy_free(struct drm_buddy *mm,
+ struct drm_buddy_block *block,
+ bool defrag)
  {
+    unsigned int order, block_order;
  struct drm_buddy_block *parent;
  +    block_order = drm_buddy_block_order(block);
+
  while ((parent = block->parent)) {
-    struct drm_buddy_block *buddy;
+    struct drm_buddy_block *buddy = NULL;
    buddy = __get_buddy(block);
    if (!drm_buddy_block_is_free(buddy))
  break;
  -    if (drm_buddy_block_is_clear(block) !=
-    drm_buddy_block_is_clear(buddy))
-    break;
+    if (!defrag) {
+    /*
+ * Check the block and its buddy clear state and exit
+ * the loop if they both have the dissimilar state.
+ */
+    if (drm_buddy_block_is_clear(block) !=
+    drm_buddy_block_is_clear(buddy))
+    break;
  -    if (drm_buddy_block_is_clear(block))
-    mark_cleared(parent);
+    if (drm_buddy_block_is_clear(block))
+    mark_cleared(parent);
+    }
+
+    WARN_ON(defrag &&
+    (drm_buddy_block_is_clear(block) ==
+ drm_buddy_block_is_clear(buddy)));
    list_del(>link);
  @@ -304,8 +320,57 @@ static void __drm_buddy_free(struct drm_buddy 
*mm,

  block = parent;
  }
  -    mark_free(mm, block);
+    order = drm_buddy_block_order(block);
+    if (block_order != order)
+    mark_free(mm, block);
+
+    return order;
+}
+
+/**
+ * drm_buddy_defrag - Defragmentation routine
+ *
+ * @mm: DRM buddy manager
+ * @min_block_size:

Re: [PATCH v7 3/3] drm/buddy: Add defragmentation support

2024-02-21 Thread Matthew Auld 

On 21/02/2024 12:18, Arunpravin Paneer Selvam wrote:

Add a function to support defragmentation.

v1:
   - Defragment the memory beginning from min_order
 till the required memory space is available.

v2(Matthew):
   - add amdgpu user for defragmentation
   - add a warning if the two blocks are incompatible on
 defragmentation
   - call full defragmentation in the fini() function
   - place a condition to test if min_order is equal to 0
   - replace the list with safe_reverse() variant as we might
 remove the block from the list.

Signed-off-by: Arunpravin Paneer Selvam 
Suggested-by: Matthew Auld 
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 +++-
  drivers/gpu/drm/drm_buddy.c  | 93 +---
  include/drm/drm_buddy.h  |  3 +
  3 files changed, 97 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index e494f5bf136a..cff8a526c622 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -533,8 +533,21 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager 
*man,
   min_block_size,
   >blocks,
   vres->flags);
-   if (unlikely(r))
-   goto error_free_blocks;
+   if (unlikely(r)) {
+   if (r == -ENOSPC) {
+   drm_buddy_defrag(mm, min_block_size);
+   r = drm_buddy_alloc_blocks(mm, fpfn,
+  lpfn,
+  size,
+  min_block_size,
+  >blocks,
+  vres->flags);
+   if (unlikely(r))
+   goto error_free_blocks;
+   } else {
+   goto error_free_blocks;
+   }
+   }
  
  		if (size > remaining_size)

remaining_size = 0;
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 18e004fa39d3..56bd1560fbcd 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -203,6 +203,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
drm_block_free(mm, mm->roots[i]);
}
  
+	drm_buddy_defrag(mm, mm->chunk_size << mm->max_order);


I think this needs to be called higher up, otherwise we blow up with the 
WARN, plus we just freed the root(s). There is also the case with 
non-power-of-two VRAM size, in which case you get multiple roots and 
max_order is just the largest root and not entire address space. I guess 
do this in the loop above and use the root order instead?


Also this should be done as part of the first patch and then in this 
patch it is just a case of exporting it. Every commit should ideally be 
functional by itself.



+
WARN_ON(mm->avail != mm->size);
  
  	kfree(mm->roots);

@@ -276,25 +278,39 @@ drm_get_buddy(struct drm_buddy_block *block)
  }
  EXPORT_SYMBOL(drm_get_buddy);
  
-static void __drm_buddy_free(struct drm_buddy *mm,

-struct drm_buddy_block *block)
+static unsigned int __drm_buddy_free(struct drm_buddy *mm,
+struct drm_buddy_block *block,
+bool defrag)
  {
+   unsigned int order, block_order;
struct drm_buddy_block *parent;
  
+	block_order = drm_buddy_block_order(block);

+
while ((parent = block->parent)) {
-   struct drm_buddy_block *buddy;
+   struct drm_buddy_block *buddy = NULL;
  
  		buddy = __get_buddy(block);
  
  		if (!drm_buddy_block_is_free(buddy))

break;
  
-		if (drm_buddy_block_is_clear(block) !=

-   drm_buddy_block_is_clear(buddy))
-   break;
+   if (!defrag) {
+   /*
+* Check the block and its buddy clear state and exit
+* the loop if they both have the dissimilar state.
+*/
+   if (drm_buddy_block_is_clear(block) !=
+   drm_buddy_block_is_clear(buddy))
+   break;
  
-		if (drm_buddy_block_is_clear(block))

-   mark_cleared(parent);
+   if (drm_buddy_block_is_clear(block))
+   mark_cleared(parent);
+   }
+
+   WARN_ON(defrag &&
+   (drm_buddy_block_is_clear(block) ==
+drm_buddy_block_is_clear(buddy)));

Re: [PATCH v7 3/3] drm/buddy: Add defragmentation support

2024-02-21 Thread Christian König 

Am 21.02.24 um 13:18 schrieb Arunpravin Paneer Selvam:

Add a function to support defragmentation.


Thinking more about it maybe you want to call this function differently.

Essentially we are force merging pages even if their cleared flag 
doesn't match, that is something different than defragmentation I think.


Maybe rename it for force_merge or something similar. Not mandatory, 
just an idea how to improve the readability of the code.


Apart from that just let me know when I can push it to drm-misc-next.

Christian.



v1:
   - Defragment the memory beginning from min_order
 till the required memory space is available.

v2(Matthew):
   - add amdgpu user for defragmentation
   - add a warning if the two blocks are incompatible on
 defragmentation
   - call full defragmentation in the fini() function
   - place a condition to test if min_order is equal to 0
   - replace the list with safe_reverse() variant as we might
 remove the block from the list.

Signed-off-by: Arunpravin Paneer Selvam 
Suggested-by: Matthew Auld 
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 +++-
  drivers/gpu/drm/drm_buddy.c  | 93 +---
  include/drm/drm_buddy.h  |  3 +
  3 files changed, 97 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index e494f5bf136a..cff8a526c622 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -533,8 +533,21 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager 
*man,
   min_block_size,
   >blocks,
   vres->flags);
-   if (unlikely(r))
-   goto error_free_blocks;
+   if (unlikely(r)) {
+   if (r == -ENOSPC) {
+   drm_buddy_defrag(mm, min_block_size);
+   r = drm_buddy_alloc_blocks(mm, fpfn,
+  lpfn,
+  size,
+  min_block_size,
+  >blocks,
+  vres->flags);
+   if (unlikely(r))
+   goto error_free_blocks;
+   } else {
+   goto error_free_blocks;
+   }
+   }
  
  		if (size > remaining_size)

remaining_size = 0;
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 18e004fa39d3..56bd1560fbcd 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -203,6 +203,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
drm_block_free(mm, mm->roots[i]);
}
  
+	drm_buddy_defrag(mm, mm->chunk_size << mm->max_order);

+
WARN_ON(mm->avail != mm->size);
  
  	kfree(mm->roots);

@@ -276,25 +278,39 @@ drm_get_buddy(struct drm_buddy_block *block)
  }
  EXPORT_SYMBOL(drm_get_buddy);
  
-static void __drm_buddy_free(struct drm_buddy *mm,

-struct drm_buddy_block *block)
+static unsigned int __drm_buddy_free(struct drm_buddy *mm,
+struct drm_buddy_block *block,
+bool defrag)
  {
+   unsigned int order, block_order;
struct drm_buddy_block *parent;
  
+	block_order = drm_buddy_block_order(block);

+
while ((parent = block->parent)) {
-   struct drm_buddy_block *buddy;
+   struct drm_buddy_block *buddy = NULL;
  
  		buddy = __get_buddy(block);
  
  		if (!drm_buddy_block_is_free(buddy))

break;
  
-		if (drm_buddy_block_is_clear(block) !=

-   drm_buddy_block_is_clear(buddy))
-   break;
+   if (!defrag) {
+   /*
+* Check the block and its buddy clear state and exit
+* the loop if they both have the dissimilar state.
+*/
+   if (drm_buddy_block_is_clear(block) !=
+   drm_buddy_block_is_clear(buddy))
+   break;
  
-		if (drm_buddy_block_is_clear(block))

-   mark_cleared(parent);
+   if (drm_buddy_block_is_clear(block))
+   mark_cleared(parent);
+   }
+
+   WARN_ON(defrag &&
+   (drm_buddy_block_is_clear(block) ==
+drm_buddy_block_is_clear(buddy)));
  
  		list_del(>link);
  
@@ -304,8 +320,57 @@ static void __drm_buddy_free(struct drm_buddy *mm,

[PATCH v7 3/3] drm/buddy: Add defragmentation support

2024-02-21 Thread Arunpravin Paneer Selvam 
Add a function to support defragmentation.

v1:
  - Defragment the memory beginning from min_order
till the required memory space is available.

v2(Matthew):
  - add amdgpu user for defragmentation
  - add a warning if the two blocks are incompatible on
defragmentation
  - call full defragmentation in the fini() function
  - place a condition to test if min_order is equal to 0
  - replace the list with safe_reverse() variant as we might
remove the block from the list.

Signed-off-by: Arunpravin Paneer Selvam 
Suggested-by: Matthew Auld 
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 +++-
 drivers/gpu/drm/drm_buddy.c  | 93 +---
 include/drm/drm_buddy.h  |  3 +
 3 files changed, 97 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index e494f5bf136a..cff8a526c622 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -533,8 +533,21 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager 
*man,
   min_block_size,
   >blocks,
   vres->flags);
-   if (unlikely(r))
-   goto error_free_blocks;
+   if (unlikely(r)) {
+   if (r == -ENOSPC) {
+   drm_buddy_defrag(mm, min_block_size);
+   r = drm_buddy_alloc_blocks(mm, fpfn,
+  lpfn,
+  size,
+  min_block_size,
+  >blocks,
+  vres->flags);
+   if (unlikely(r))
+   goto error_free_blocks;
+   } else {
+   goto error_free_blocks;
+   }
+   }
 
if (size > remaining_size)
remaining_size = 0;
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 18e004fa39d3..56bd1560fbcd 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -203,6 +203,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
drm_block_free(mm, mm->roots[i]);
}
 
+   drm_buddy_defrag(mm, mm->chunk_size << mm->max_order);
+
WARN_ON(mm->avail != mm->size);
 
kfree(mm->roots);
@@ -276,25 +278,39 @@ drm_get_buddy(struct drm_buddy_block *block)
 }
 EXPORT_SYMBOL(drm_get_buddy);
 
-static void __drm_buddy_free(struct drm_buddy *mm,
-struct drm_buddy_block *block)
+static unsigned int __drm_buddy_free(struct drm_buddy *mm,
+struct drm_buddy_block *block,
+bool defrag)
 {
+   unsigned int order, block_order;
struct drm_buddy_block *parent;
 
+   block_order = drm_buddy_block_order(block);
+
while ((parent = block->parent)) {
-   struct drm_buddy_block *buddy;
+   struct drm_buddy_block *buddy = NULL;
 
buddy = __get_buddy(block);
 
if (!drm_buddy_block_is_free(buddy))
break;
 
-   if (drm_buddy_block_is_clear(block) !=
-   drm_buddy_block_is_clear(buddy))
-   break;
+   if (!defrag) {
+   /*
+* Check the block and its buddy clear state and exit
+* the loop if they both have the dissimilar state.
+*/
+   if (drm_buddy_block_is_clear(block) !=
+   drm_buddy_block_is_clear(buddy))
+   break;
 
-   if (drm_buddy_block_is_clear(block))
-   mark_cleared(parent);
+   if (drm_buddy_block_is_clear(block))
+   mark_cleared(parent);
+   }
+
+   WARN_ON(defrag &&
+   (drm_buddy_block_is_clear(block) ==
+drm_buddy_block_is_clear(buddy)));
 
list_del(>link);
 
@@ -304,8 +320,57 @@ static void __drm_buddy_free(struct drm_buddy *mm,
block = parent;
}
 
-   mark_free(mm, block);
+   order = drm_buddy_block_order(block);
+   if (block_order != order)
+   mark_free(mm, block);
+
+   return order;
+}
+
+/**
+ * drm_buddy_defrag - Defragmentation routine
+ *
+ * @mm: DRM buddy manager
+ * @min_block_size: minimum size in bytes to begin
+ * the defragmentation process
+ *
+ * Driver calls the defragmentation