From 3a41a05d70b4fb455256fd3a8348e186f156c310 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Micha=C5=82=20Winiarski?= Date: Thu, 3 Sep 2015 19:22:18 +0200 Subject: [PATCH] drm/i915/gtt: Avoid calling kcalloc in a loop when allocating temp bitmaps MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Cc: Mika Kuoppala Cc: Michel Thierry Signed-off-by: Michał Winiarski Reviewed-by: Chris Wilson [danvet: Correct kcalloc arguments as suggested by Chris.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_gtt.c | 49 +++++++++++------------------ 1 file changed, 18 insertions(+), 31 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index bdb7adc7359e..87862813cfde 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1164,13 +1164,8 @@ unwind_out: } 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 @@ free_gen8_temp_bitmaps(unsigned long *new_pds, unsigned long **new_pts, */ 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 @@ int __must_check alloc_gen8_temp_bitmaps(unsigned long **new_pds, return 0; err_out: - free_gen8_temp_bitmaps(pds, pts, pdpes); + free_gen8_temp_bitmaps(pds, pts); return -ENOMEM; } @@ -1231,7 +1217,7 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm, { 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 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm, 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 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm, 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 void gen8_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m) 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 @@ static int gen8_preallocate_top_level_pdps(struct i915_hw_ppgtt *ppgtt) 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; } -- 2.20.1