[PATCH 1/2] drm/ttm: Move swapped objects off the manager's LRU list
Thomas Hellström
thomas.hellstrom at linux.intel.com
Mon Sep 2 15:41:58 UTC 2024
Resources of swapped objects remains on the TTM_PL_SYSTEM manager's
LRU list, which is bad for the LRU walk efficiency.
Rename the device-wide "pinned" list to "unevictable" and move
also resources of swapped-out objects to that list.
An alternative would be to create an "UNEVICTABLE" priority to
be able to keep the pinned- and swapped objects on their
respective manager's LRU without affecting the LRU walk efficiency.
Cc: Christian König <christian.koenig at amd.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Cc: <dri-devel at lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c | 4 +-
drivers/gpu/drm/ttm/ttm_bo.c | 55 +++++++++++++++++++-
drivers/gpu/drm/ttm/ttm_bo_util.c | 6 +--
drivers/gpu/drm/ttm/ttm_bo_vm.c | 2 +-
drivers/gpu/drm/ttm/ttm_device.c | 4 +-
drivers/gpu/drm/ttm/ttm_resource.c | 9 ++--
drivers/gpu/drm/ttm/ttm_tt.c | 1 -
drivers/gpu/drm/xe/xe_bo.c | 4 +-
include/drm/ttm/ttm_bo.h | 2 +
include/drm/ttm/ttm_device.h | 5 +-
include/drm/ttm/ttm_tt.h | 5 ++
13 files changed, 81 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 5c72462d1f57..7de284766f82 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -808,7 +808,7 @@ static int __i915_ttm_get_pages(struct drm_i915_gem_object *obj,
}
if (bo->ttm && !ttm_tt_is_populated(bo->ttm)) {
- ret = ttm_tt_populate(bo->bdev, bo->ttm, &ctx);
+ ret = ttm_bo_populate(bo, &ctx);
if (ret)
return ret;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
index 03b00a03a634..041dab543b78 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
@@ -624,7 +624,7 @@ int i915_ttm_move(struct ttm_buffer_object *bo, bool evict,
/* Populate ttm with pages if needed. Typically system memory. */
if (ttm && (dst_man->use_tt || (ttm->page_flags & TTM_TT_FLAG_SWAPPED))) {
- ret = ttm_tt_populate(bo->bdev, ttm, ctx);
+ ret = ttm_bo_populate(bo, ctx);
if (ret)
return ret;
}
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
index ad649523d5e0..61596cecce4d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_pm.c
@@ -90,7 +90,7 @@ static int i915_ttm_backup(struct i915_gem_apply_to_region *apply,
goto out_no_lock;
backup_bo = i915_gem_to_ttm(backup);
- err = ttm_tt_populate(backup_bo->bdev, backup_bo->ttm, &ctx);
+ err = ttm_bo_populate(backup_bo, &ctx);
if (err)
goto out_no_populate;
@@ -189,7 +189,7 @@ static int i915_ttm_restore(struct i915_gem_apply_to_region *apply,
if (!backup_bo->resource)
err = ttm_bo_validate(backup_bo, i915_ttm_sys_placement(), &ctx);
if (!err)
- err = ttm_tt_populate(backup_bo->bdev, backup_bo->ttm, &ctx);
+ err = ttm_bo_populate(backup_bo, &ctx);
if (!err) {
err = i915_gem_obj_copy_ttm(obj, backup, pm_apply->allow_gpu,
false);
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 320592435252..d244566a7e48 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -139,7 +139,7 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
goto out_err;
if (mem->mem_type != TTM_PL_SYSTEM) {
- ret = ttm_tt_populate(bo->bdev, bo->ttm, ctx);
+ ret = ttm_bo_populate(bo, ctx);
if (ret)
goto out_err;
}
@@ -1131,6 +1131,13 @@ ttm_bo_swapout_cb(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo)
if (ttm_tt_is_populated(bo->ttm))
ret = ttm_tt_swapout(bo->bdev, bo->ttm, swapout_walk->gfp_flags);
+ if (ttm_tt_is_swapped(bo->ttm)) {
+ spin_lock(&bo->bdev->lru_lock);
+ ttm_resource_del_bulk_move(bo->resource, bo);
+ ttm_resource_move_to_lru_tail(bo->resource);
+ spin_unlock(&bo->bdev->lru_lock);
+ }
+
out:
/* Consider -ENOMEM and -ENOSPC non-fatal. */
if (ret == -ENOMEM || ret == -ENOSPC)
@@ -1180,3 +1187,49 @@ void ttm_bo_tt_destroy(struct ttm_buffer_object *bo)
ttm_tt_destroy(bo->bdev, bo->ttm);
bo->ttm = NULL;
}
+
+/**
+ * ttm_bo_populate() - Ensure that a buffer object has backing pages
+ * @bo: The buffer object
+ * @ctx: The ttm_operation_ctx governing the operation.
+ *
+ * For buffer objects in a memory type whose manager uses
+ * struct ttm_tt for backing pages, ensure those backing pages
+ * are present and with valid content. The bo's resource is also
+ * placed on the correct LRU list if it was previously swapped
+ * out.
+ *
+ * Return: 0 if successful, negative error code on failure.
+ * Note: May return -EINTR or -ERESTARTSYS if @ctx::interruptible
+ * is set to true.
+ */
+int ttm_bo_populate(struct ttm_buffer_object *bo,
+ struct ttm_operation_ctx *ctx)
+{
+ struct ttm_tt *tt = bo->ttm;
+ bool swapped;
+ int ret;
+
+ dma_resv_assert_held(bo->base.resv);
+
+ if (!tt)
+ return 0;
+
+ swapped = ttm_tt_is_swapped(tt);
+ ret = ttm_tt_populate(bo->bdev, tt, ctx);
+ if (ret)
+ return ret;
+
+ if (swapped && !ttm_tt_is_swapped(tt) && !bo->pin_count) {
+ if (WARN_ON_ONCE(bo->pin_count))
+ return 0;
+
+ spin_lock(&bo->bdev->lru_lock);
+ ttm_resource_add_bulk_move(bo->resource, bo);
+ ttm_resource_move_to_lru_tail(bo->resource);
+ spin_unlock(&bo->bdev->lru_lock);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(ttm_bo_populate);
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 3c07f4712d5c..d939925efa81 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -163,7 +163,7 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
src_man = ttm_manager_type(bdev, src_mem->mem_type);
if (ttm && ((ttm->page_flags & TTM_TT_FLAG_SWAPPED) ||
dst_man->use_tt)) {
- ret = ttm_tt_populate(bdev, ttm, ctx);
+ ret = ttm_bo_populate(bo, ctx);
if (ret)
return ret;
}
@@ -350,7 +350,7 @@ static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
BUG_ON(!ttm);
- ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
+ ret = ttm_bo_populate(bo, &ctx);
if (ret)
return ret;
@@ -507,7 +507,7 @@ int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map)
pgprot_t prot;
void *vaddr;
- ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
+ ret = ttm_bo_populate(bo, &ctx);
if (ret)
return ret;
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 4212b8c91dd4..2c699ed1963a 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -224,7 +224,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
};
ttm = bo->ttm;
- err = ttm_tt_populate(bdev, bo->ttm, &ctx);
+ err = ttm_bo_populate(bo, &ctx);
if (err) {
if (err == -EINTR || err == -ERESTARTSYS ||
err == -EAGAIN)
diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
index e7cc4954c1bc..02e797fd1891 100644
--- a/drivers/gpu/drm/ttm/ttm_device.c
+++ b/drivers/gpu/drm/ttm/ttm_device.c
@@ -216,7 +216,7 @@ int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *func
bdev->vma_manager = vma_manager;
spin_lock_init(&bdev->lru_lock);
- INIT_LIST_HEAD(&bdev->pinned);
+ INIT_LIST_HEAD(&bdev->unevictable);
bdev->dev_mapping = mapping;
mutex_lock(&ttm_global_mutex);
list_add_tail(&bdev->device_list, &glob->device_list);
@@ -283,7 +283,7 @@ void ttm_device_clear_dma_mappings(struct ttm_device *bdev)
struct ttm_resource_manager *man;
unsigned int i, j;
- ttm_device_clear_lru_dma_mappings(bdev, &bdev->pinned);
+ ttm_device_clear_lru_dma_mappings(bdev, &bdev->unevictable);
for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
man = ttm_manager_type(bdev, i);
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index 6d764ba88aab..9d54c0e3e43d 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -30,6 +30,7 @@
#include <drm/ttm/ttm_bo.h>
#include <drm/ttm/ttm_placement.h>
#include <drm/ttm/ttm_resource.h>
+#include <drm/ttm/ttm_tt.h>
#include <drm/drm_util.h>
@@ -259,8 +260,8 @@ void ttm_resource_move_to_lru_tail(struct ttm_resource *res)
lockdep_assert_held(&bo->bdev->lru_lock);
- if (bo->pin_count) {
- list_move_tail(&res->lru.link, &bdev->pinned);
+ if (bo->pin_count || (bo->ttm && ttm_tt_is_swapped(bo->ttm))) {
+ list_move_tail(&res->lru.link, &bdev->unevictable);
} else if (bo->bulk_move) {
struct ttm_lru_bulk_move_pos *pos =
@@ -301,8 +302,8 @@ void ttm_resource_init(struct ttm_buffer_object *bo,
man = ttm_manager_type(bo->bdev, place->mem_type);
spin_lock(&bo->bdev->lru_lock);
- if (bo->pin_count)
- list_add_tail(&res->lru.link, &bo->bdev->pinned);
+ if (bo->pin_count || (bo->ttm && ttm_tt_is_swapped(bo->ttm)))
+ list_add_tail(&res->lru.link, &bo->bdev->unevictable);
else
list_add_tail(&res->lru.link, &man->lru[bo->priority]);
man->usage += res->size;
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 4b51b9023126..d1325cf37b18 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -367,7 +367,6 @@ int ttm_tt_populate(struct ttm_device *bdev,
}
return ret;
}
-EXPORT_SYMBOL(ttm_tt_populate);
void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
{
diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 9df5a16662cf..d7d0add20b77 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -903,7 +903,7 @@ int xe_bo_evict_pinned(struct xe_bo *bo)
}
}
- ret = ttm_tt_populate(bo->ttm.bdev, bo->ttm.ttm, &ctx);
+ ret = ttm_bo_populate(&bo->ttm, &ctx);
if (ret)
goto err_res_free;
@@ -956,7 +956,7 @@ int xe_bo_restore_pinned(struct xe_bo *bo)
if (ret)
return ret;
- ret = ttm_tt_populate(bo->ttm.bdev, bo->ttm.ttm, &ctx);
+ ret = ttm_bo_populate(&bo->ttm, &ctx);
if (ret)
goto err_res_free;
diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
index 7b56d1ca36d7..5804408815be 100644
--- a/include/drm/ttm/ttm_bo.h
+++ b/include/drm/ttm/ttm_bo.h
@@ -462,5 +462,7 @@ int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo);
pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res,
pgprot_t tmp);
void ttm_bo_tt_destroy(struct ttm_buffer_object *bo);
+int ttm_bo_populate(struct ttm_buffer_object *bo,
+ struct ttm_operation_ctx *ctx);
#endif
diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
index c22f30535c84..438358f72716 100644
--- a/include/drm/ttm/ttm_device.h
+++ b/include/drm/ttm/ttm_device.h
@@ -252,9 +252,10 @@ struct ttm_device {
spinlock_t lru_lock;
/**
- * @pinned: Buffer objects which are pinned and so not on any LRU list.
+ * @unevictable Buffer objects which are pinned or swapped and as such
+ * not on an LRU list.
*/
- struct list_head pinned;
+ struct list_head unevictable;
/**
* @dev_mapping: A pointer to the struct address_space for invalidating
diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h
index 2b9d856ff388..991edafdb2dd 100644
--- a/include/drm/ttm/ttm_tt.h
+++ b/include/drm/ttm/ttm_tt.h
@@ -129,6 +129,11 @@ static inline bool ttm_tt_is_populated(struct ttm_tt *tt)
return tt->page_flags & TTM_TT_FLAG_PRIV_POPULATED;
}
+static inline bool ttm_tt_is_swapped(const struct ttm_tt *tt)
+{
+ return tt->page_flags & TTM_TT_FLAG_SWAPPED;
+}
+
/**
* ttm_tt_create
*
--
2.46.0
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