6.12-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Hellström thomas.hellstrom@linux.intel.com
commit 5c87fee3c96ce898ad681552404a66c7605193c0 upstream.
VRAM+TT bos that are evicted from VRAM to TT may remain in TT also after a revalidation following eviction or suspend.
This manifests itself as applications becoming sluggish after buffer objects get evicted or after a resume from suspend or hibernation.
If the bo supports placement in both VRAM and TT, and we are on DGFX, mark the TT placement as fallback. This means that it is tried only after VRAM + eviction.
This flaw has probably been present since the xe module was upstreamed but use a Fixes: commit below where backporting is likely to be simple. For earlier versions we need to open- code the fallback algorithm in the driver.
v2: - Remove check for dgfx. (Matthew Auld) - Update the xe_dma_buf kunit test for the new strategy (CI) - Allow dma-buf to pin in current placement (CI) - Make xe_bo_validate() for pinned bos a NOP.
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/5995 Fixes: a78a8da51b36 ("drm/ttm: replace busy placement with flags v6") Cc: Matthew Brost matthew.brost@intel.com Cc: Matthew Auld matthew.auld@intel.com Cc: stable@vger.kernel.org # v6.9+ Signed-off-by: Thomas Hellström thomas.hellstrom@linux.intel.com Reviewed-by: Matthew Auld matthew.auld@intel.com Link: https://lore.kernel.org/r/20250904160715.2613-2-thomas.hellstrom@linux.intel... (cherry picked from commit cb3d7b3b46b799c96b54f8e8fe36794a55a77f0b) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/xe/tests/xe_bo.c | 2 +- drivers/gpu/drm/xe/tests/xe_dma_buf.c | 10 +--------- drivers/gpu/drm/xe/xe_bo.c | 16 ++++++++++++---- drivers/gpu/drm/xe/xe_bo.h | 2 +- drivers/gpu/drm/xe/xe_dma_buf.c | 2 +- 5 files changed, 16 insertions(+), 16 deletions(-)
--- a/drivers/gpu/drm/xe/tests/xe_bo.c +++ b/drivers/gpu/drm/xe/tests/xe_bo.c @@ -222,7 +222,7 @@ static int evict_test_run_tile(struct xe }
xe_bo_lock(external, false); - err = xe_bo_pin_external(external); + err = xe_bo_pin_external(external, false); xe_bo_unlock(external); if (err) { KUNIT_FAIL(test, "external bo pin err=%pe\n", --- a/drivers/gpu/drm/xe/tests/xe_dma_buf.c +++ b/drivers/gpu/drm/xe/tests/xe_dma_buf.c @@ -89,15 +89,7 @@ static void check_residency(struct kunit return; }
- /* - * If on different devices, the exporter is kept in system if - * possible, saving a migration step as the transfer is just - * likely as fast from system memory. - */ - if (params->mem_mask & XE_BO_FLAG_SYSTEM) - KUNIT_EXPECT_TRUE(test, xe_bo_is_mem_type(exported, XE_PL_TT)); - else - KUNIT_EXPECT_TRUE(test, xe_bo_is_mem_type(exported, mem_type)); + KUNIT_EXPECT_TRUE(test, xe_bo_is_mem_type(exported, mem_type));
if (params->force_different_devices) KUNIT_EXPECT_TRUE(test, xe_bo_is_mem_type(imported, XE_PL_TT)); --- a/drivers/gpu/drm/xe/xe_bo.c +++ b/drivers/gpu/drm/xe/xe_bo.c @@ -157,6 +157,8 @@ static void try_add_system(struct xe_dev
bo->placements[*c] = (struct ttm_place) { .mem_type = XE_PL_TT, + .flags = (bo_flags & XE_BO_FLAG_VRAM_MASK) ? + TTM_PL_FLAG_FALLBACK : 0, }; *c += 1; } @@ -1743,6 +1745,7 @@ uint64_t vram_region_gpu_offset(struct t /** * xe_bo_pin_external - pin an external BO * @bo: buffer object to be pinned + * @in_place: Pin in current placement, don't attempt to migrate. * * Pin an external (not tied to a VM, can be exported via dma-buf / prime FD) * BO. Unique call compared to xe_bo_pin as this function has it own set of @@ -1750,7 +1753,7 @@ uint64_t vram_region_gpu_offset(struct t * * Returns 0 for success, negative error code otherwise. */ -int xe_bo_pin_external(struct xe_bo *bo) +int xe_bo_pin_external(struct xe_bo *bo, bool in_place) { struct xe_device *xe = xe_bo_device(bo); int err; @@ -1759,9 +1762,11 @@ int xe_bo_pin_external(struct xe_bo *bo) xe_assert(xe, xe_bo_is_user(bo));
if (!xe_bo_is_pinned(bo)) { - err = xe_bo_validate(bo, NULL, false); - if (err) - return err; + if (!in_place) { + err = xe_bo_validate(bo, NULL, false); + if (err) + return err; + }
if (xe_bo_is_vram(bo)) { spin_lock(&xe->pinned.lock); @@ -1913,6 +1918,9 @@ int xe_bo_validate(struct xe_bo *bo, str .no_wait_gpu = false, };
+ if (xe_bo_is_pinned(bo)) + return 0; + if (vm) { lockdep_assert_held(&vm->lock); xe_vm_assert_held(vm); --- a/drivers/gpu/drm/xe/xe_bo.h +++ b/drivers/gpu/drm/xe/xe_bo.h @@ -173,7 +173,7 @@ static inline void xe_bo_unlock_vm_held( } }
-int xe_bo_pin_external(struct xe_bo *bo); +int xe_bo_pin_external(struct xe_bo *bo, bool in_place); int xe_bo_pin(struct xe_bo *bo); void xe_bo_unpin_external(struct xe_bo *bo); void xe_bo_unpin(struct xe_bo *bo); --- a/drivers/gpu/drm/xe/xe_dma_buf.c +++ b/drivers/gpu/drm/xe/xe_dma_buf.c @@ -72,7 +72,7 @@ static int xe_dma_buf_pin(struct dma_buf return ret; }
- ret = xe_bo_pin_external(bo); + ret = xe_bo_pin_external(bo, true); xe_assert(xe, !ret);
return 0;