drm/i915/gtt: Avoid calling kcalloc in a loop when allocating temp bitmaps
On each call to gen8_alloc_va_range_3lvl we're allocating temporary
bitmaps needed for error handling. Unfortunately, when we increase
address space size (48b ppgtt) we do additional (512 - 4) calls to
kcalloc, increasing latency between exec and actual start of execution
on the GPU. Let's just do a single kcalloc, we can also drop the size
from free_gen8_temp_bitmaps since it's no longer used.
v2: Use GFP_TEMPORARY to make the allocations reclaimable.
v3: Drop the 2D array, just allocate a single block.
v4: Rebase to handle gen8_preallocate_top_level_pdps.
v5: Align misaligned bracket.
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Correct kcalloc arguments as suggested by Chris.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index bdb7adc..8786281 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1164,13 +1164,8 @@
}
static void
-free_gen8_temp_bitmaps(unsigned long *new_pds, unsigned long **new_pts,
- uint32_t pdpes)
+free_gen8_temp_bitmaps(unsigned long *new_pds, unsigned long *new_pts)
{
- int i;
-
- for (i = 0; i < pdpes; i++)
- kfree(new_pts[i]);
kfree(new_pts);
kfree(new_pds);
}
@@ -1180,29 +1175,20 @@
*/
static
int __must_check alloc_gen8_temp_bitmaps(unsigned long **new_pds,
- unsigned long ***new_pts,
+ unsigned long **new_pts,
uint32_t pdpes)
{
- int i;
unsigned long *pds;
- unsigned long **pts;
+ unsigned long *pts;
- pds = kcalloc(BITS_TO_LONGS(pdpes), sizeof(unsigned long), GFP_KERNEL);
+ pds = kcalloc(BITS_TO_LONGS(pdpes), sizeof(unsigned long), GFP_TEMPORARY);
if (!pds)
return -ENOMEM;
- pts = kcalloc(pdpes, sizeof(unsigned long *), GFP_KERNEL);
- if (!pts) {
- kfree(pds);
- return -ENOMEM;
- }
-
- for (i = 0; i < pdpes; i++) {
- pts[i] = kcalloc(BITS_TO_LONGS(I915_PDES),
- sizeof(unsigned long), GFP_KERNEL);
- if (!pts[i])
- goto err_out;
- }
+ pts = kcalloc(pdpes, BITS_TO_LONGS(I915_PDES) * sizeof(unsigned long),
+ GFP_TEMPORARY);
+ if (!pts)
+ goto err_out;
*new_pds = pds;
*new_pts = pts;
@@ -1210,7 +1196,7 @@
return 0;
err_out:
- free_gen8_temp_bitmaps(pds, pts, pdpes);
+ free_gen8_temp_bitmaps(pds, pts);
return -ENOMEM;
}
@@ -1231,7 +1217,7 @@
{
struct i915_hw_ppgtt *ppgtt =
container_of(vm, struct i915_hw_ppgtt, base);
- unsigned long *new_page_dirs, **new_page_tables;
+ unsigned long *new_page_dirs, *new_page_tables;
struct drm_device *dev = vm->dev;
struct i915_page_directory *pd;
const uint64_t orig_start = start;
@@ -1258,14 +1244,14 @@
ret = gen8_ppgtt_alloc_page_directories(vm, pdp, start, length,
new_page_dirs);
if (ret) {
- free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
+ free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
return ret;
}
/* For every page directory referenced, allocate page tables */
gen8_for_each_pdpe(pd, pdp, start, length, temp, pdpe) {
ret = gen8_ppgtt_alloc_pagetabs(vm, pd, start, length,
- new_page_tables[pdpe]);
+ new_page_tables + pdpe * BITS_TO_LONGS(I915_PDES));
if (ret)
goto err_out;
}
@@ -1316,20 +1302,21 @@
gen8_setup_page_directory(ppgtt, pdp, pd, pdpe);
}
- free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
+ free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
mark_tlbs_dirty(ppgtt);
return 0;
err_out:
while (pdpe--) {
- for_each_set_bit(temp, new_page_tables[pdpe], I915_PDES)
+ for_each_set_bit(temp, new_page_tables + pdpe *
+ BITS_TO_LONGS(I915_PDES), I915_PDES)
free_pt(dev, pdp->page_directory[pdpe]->page_table[temp]);
}
for_each_set_bit(pdpe, new_page_dirs, pdpes)
free_pd(dev, pdp->page_directory[pdpe]);
- free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
+ free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
mark_tlbs_dirty(ppgtt);
return ret;
}
@@ -1481,7 +1468,7 @@
static int gen8_preallocate_top_level_pdps(struct i915_hw_ppgtt *ppgtt)
{
- unsigned long *new_page_dirs, **new_page_tables;
+ unsigned long *new_page_dirs, *new_page_tables;
uint32_t pdpes = I915_PDPES_PER_PDP(dev);
int ret;
@@ -1501,7 +1488,7 @@
if (!ret)
*ppgtt->pdp.used_pdpes = *new_page_dirs;
- free_gen8_temp_bitmaps(new_page_dirs, new_page_tables, pdpes);
+ free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
return ret;
}