[RFC PATCH v3 13/21] drm/exec: Rework contended locking
Christian König
christian.koenig at amd.com
Wed May 22 05:52:16 UTC 2024
Am 21.05.24 um 09:16 schrieb Thomas Hellström:
> If contention and backoff occurs during a drm_exec ww transaction,
> the contended lock is not locked again until the next orinary
> attempt to lock a dma_resv lock. However, with the introduction of
> drm_exec_trylock(), that doesn't work, since the locking of the
> contended lock needs to be a sleeping lock. Neither can we ignore
> locking the contended lock during a trylock since that would violate
> at least the ww_mutex annotations.
>
> So resolve this by actually locking the contended lock during
> drm_exec_retry_on_contention(). However, this introduces a new point
> of failure since locking the contended lock may return -EINTR.
>
> Hence drm_exec_retry_on_contention() must take an error parameter and
> also return a value indicating success.
After thinking more about that I have to pretty clearly NAK this.
It's an intentional design decision to guarantee that at the start of
the loop no object is locked.
This is because Sima and I wanted to integrate userptr handling into
drm_exec as well in the long term.
I think we should just document that drm_exec_trylock() can't be used to
lock the first BO in the loop and explicitly WARN if that's the case.
Regards,
Christian.
>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Somalapuram Amaranath <Amaranath.Somalapuram 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>
> ---
> .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 16 ++++-----
> drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 6 ++--
> drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c | 4 +--
> drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 8 ++---
> drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c | 8 ++---
> drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c | 4 +--
> drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c | 8 ++---
> drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 2 +-
> drivers/gpu/drm/drm_exec.c | 35 ++++++++++++++-----
> drivers/gpu/drm/drm_gpuvm.c | 8 ++---
> drivers/gpu/drm/imagination/pvr_job.c | 2 +-
> drivers/gpu/drm/msm/msm_gem_submit.c | 2 +-
> drivers/gpu/drm/nouveau/nouveau_uvmm.c | 2 +-
> drivers/gpu/drm/tests/drm_exec_test.c | 12 +++----
> drivers/gpu/drm/xe/xe_gt_pagefault.c | 4 +--
> drivers/gpu/drm/xe/xe_vm.c | 10 +++---
> include/drm/drm_exec.h | 23 +++++++++---
> 17 files changed, 92 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> index e4d4e55c08ad..4a08a692aa1f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> @@ -1152,12 +1152,12 @@ static int reserve_bo_and_vm(struct kgd_mem *mem,
> drm_exec_init(&ctx->exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
> drm_exec_until_all_locked(&ctx->exec) {
> ret = amdgpu_vm_lock_pd(vm, &ctx->exec, 2);
> - drm_exec_retry_on_contention(&ctx->exec);
> + ret = drm_exec_retry_on_contention(&ctx->exec, ret);
> if (unlikely(ret))
> goto error;
>
> ret = drm_exec_prepare_obj(&ctx->exec, &bo->tbo.base, 1);
> - drm_exec_retry_on_contention(&ctx->exec);
> + ret = drm_exec_retry_on_contention(&ctx->exec, ret);
> if (unlikely(ret))
> goto error;
> }
> @@ -1199,14 +1199,14 @@ static int reserve_bo_and_cond_vms(struct kgd_mem *mem,
>
> ret = amdgpu_vm_lock_pd(entry->bo_va->base.vm,
> &ctx->exec, 2);
> - drm_exec_retry_on_contention(&ctx->exec);
> + ret = drm_exec_retry_on_contention(&ctx->exec, ret);
> if (unlikely(ret))
> goto error;
> ++ctx->n_vms;
> }
>
> ret = drm_exec_prepare_obj(&ctx->exec, &bo->tbo.base, 1);
> - drm_exec_retry_on_contention(&ctx->exec);
> + ret = drm_exec_retry_on_contention(&ctx->exec, ret);
> if (unlikely(ret))
> goto error;
> }
> @@ -2619,7 +2619,7 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
> list_for_each_entry(peer_vm, &process_info->vm_list_head,
> vm_list_node) {
> ret = amdgpu_vm_lock_pd(peer_vm, &exec, 2);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> if (unlikely(ret))
> goto unreserve_out;
> }
> @@ -2631,7 +2631,7 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
>
> gobj = &mem->bo->tbo.base;
> ret = drm_exec_prepare_obj(&exec, gobj, 1);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> if (unlikely(ret))
> goto unreserve_out;
> }
> @@ -2875,7 +2875,7 @@ int amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct dma_fence __rcu *
> list_for_each_entry(peer_vm, &process_info->vm_list_head,
> vm_list_node) {
> ret = amdgpu_vm_lock_pd(peer_vm, &exec, 2);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> if (unlikely(ret)) {
> pr_err("Locking VM PD failed, ret: %d\n", ret);
> goto ttm_reserve_fail;
> @@ -2891,7 +2891,7 @@ int amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct dma_fence __rcu *
>
> gobj = &mem->bo->tbo.base;
> ret = drm_exec_prepare_obj(&exec, gobj, 1);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> if (unlikely(ret)) {
> pr_err("drm_exec_prepare_obj failed, ret: %d\n", ret);
> goto ttm_reserve_fail;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index ec888fc6ead8..299e46a6d934 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -897,7 +897,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
>
> drm_exec_until_all_locked(&p->exec) {
> r = amdgpu_vm_lock_pd(&fpriv->vm, &p->exec, 1 + p->gang_size);
> - drm_exec_retry_on_contention(&p->exec);
> + r = drm_exec_retry_on_contention(&p->exec, r);
> if (unlikely(r))
> goto out_free_user_pages;
>
> @@ -905,7 +905,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
> /* One fence for TTM and one for each CS job */
> r = drm_exec_prepare_obj(&p->exec, &e->bo->tbo.base,
> 1 + p->gang_size);
> - drm_exec_retry_on_contention(&p->exec);
> + r = drm_exec_retry_on_contention(&p->exec, r);
> if (unlikely(r))
> goto out_free_user_pages;
>
> @@ -915,7 +915,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
> if (p->uf_bo) {
> r = drm_exec_prepare_obj(&p->exec, &p->uf_bo->tbo.base,
> 1 + p->gang_size);
> - drm_exec_retry_on_contention(&p->exec);
> + r = drm_exec_retry_on_contention(&p->exec, r);
> if (unlikely(r))
> goto out_free_user_pages;
> }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c
> index cfdf558b48b6..8b2b86c7a6c5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c
> @@ -74,7 +74,7 @@ int amdgpu_map_static_csa(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> if (likely(!r))
> r = drm_exec_lock_obj(&exec, &bo->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r)) {
> DRM_ERROR("failed to reserve CSA,PD BOs: err=%d\n", r);
> goto error;
> @@ -114,7 +114,7 @@ int amdgpu_unmap_static_csa(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> if (likely(!r))
> r = drm_exec_lock_obj(&exec, &bo->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r)) {
> DRM_ERROR("failed to reserve CSA,PD BOs: err=%d\n", r);
> goto error;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> index 67c234bcf89f..17e16c971e21 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> @@ -239,12 +239,12 @@ static void amdgpu_gem_object_close(struct drm_gem_object *obj,
> drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);
> drm_exec_until_all_locked(&exec) {
> r = drm_exec_prepare_obj(&exec, &bo->tbo.base, 1);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto out_unlock;
>
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto out_unlock;
> }
> @@ -776,13 +776,13 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
> drm_exec_until_all_locked(&exec) {
> if (gobj) {
> r = drm_exec_lock_obj(&exec, gobj);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error;
> }
>
> r = amdgpu_vm_lock_pd(&fpriv->vm, &exec, 2);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error;
> }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c
> index 5ca5c47ab54e..1b1a5147606e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c
> @@ -1221,12 +1221,12 @@ int amdgpu_mes_ctx_map_meta_data(struct amdgpu_device *adev,
> drm_exec_until_all_locked(&exec) {
> r = drm_exec_lock_obj(&exec,
> &ctx_data->meta_data_obj->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error_fini_exec;
>
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error_fini_exec;
> }
> @@ -1292,12 +1292,12 @@ int amdgpu_mes_ctx_unmap_meta_data(struct amdgpu_device *adev,
> drm_exec_until_all_locked(&exec) {
> r = drm_exec_lock_obj(&exec,
> &ctx_data->meta_data_obj->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto out_unlock;
>
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto out_unlock;
> }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
> index e22cb2b5cd92..72b8213e352c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
> @@ -77,7 +77,7 @@ int amdgpu_seq64_map(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> if (likely(!r))
> r = drm_exec_lock_obj(&exec, &bo->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error;
> }
> @@ -138,7 +138,7 @@ void amdgpu_seq64_unmap(struct amdgpu_device *adev, struct amdgpu_fpriv *fpriv)
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> if (likely(!r))
> r = drm_exec_lock_obj(&exec, &bo->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error;
> }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c
> index e01c1c8e64c4..63392ce43945 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c
> @@ -89,12 +89,12 @@ static int map_ring_data(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> drm_exec_init(&exec, 0, 0);
> drm_exec_until_all_locked(&exec) {
> r = drm_exec_lock_obj(&exec, &bo->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error_fini_exec;
>
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto error_fini_exec;
> }
> @@ -152,12 +152,12 @@ static int unmap_ring_data(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> drm_exec_init(&exec, 0, 0);
> drm_exec_until_all_locked(&exec) {
> r = drm_exec_lock_obj(&exec, &bo->tbo.base);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto out_unlock;
>
> r = amdgpu_vm_lock_pd(vm, &exec, 0);
> - drm_exec_retry_on_contention(&exec);
> + r = drm_exec_retry_on_contention(&exec, r);
> if (unlikely(r))
> goto out_unlock;
> }
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 386875e6eb96..a3aa7fd22f6a 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -1499,7 +1499,7 @@ static int svm_range_reserve_bos(struct svm_validate_context *ctx, bool intr)
> vm = drm_priv_to_vm(pdd->drm_priv);
>
> r = amdgpu_vm_lock_pd(vm, &ctx->exec, 2);
> - drm_exec_retry_on_contention(&ctx->exec);
> + r = drm_exec_retry_on_contention(&ctx->exec, r);
> if (unlikely(r)) {
> pr_debug("failed %d to reserve bo\n", r);
> goto unreserve_out;
> diff --git a/drivers/gpu/drm/drm_exec.c b/drivers/gpu/drm/drm_exec.c
> index 2da094bdf8a4..3770a5d30213 100644
> --- a/drivers/gpu/drm/drm_exec.c
> +++ b/drivers/gpu/drm/drm_exec.c
> @@ -28,12 +28,12 @@
> * drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT);
> * drm_exec_until_all_locked(&exec) {
> * ret = drm_exec_prepare_obj(&exec, boA, 1);
> - * drm_exec_retry_on_contention(&exec);
> + * ret = drm_exec_retry_on_contention(&exec, ret);
> * if (ret)
> * goto error;
> *
> * ret = drm_exec_prepare_obj(&exec, boB, 1);
> - * drm_exec_retry_on_contention(&exec);
> + * ret = drm_exec_retry_on_contention(&exec, ret);
> * if (ret)
> * goto error;
> * }
> @@ -48,7 +48,8 @@
> */
>
> /* Dummy value used to initially enter the retry loop */
> -#define DRM_EXEC_DUMMY ((void *)~0)
> +#define DRM_EXEC_DUMMY ERR_PTR(-ESTALE)
> +#define DRM_EXEC_CONTENDED ERR_PTR(-EDEADLK)
>
> /* Unlock all objects and drop references */
> static void drm_exec_unlock_all(struct drm_exec *exec)
> @@ -131,8 +132,7 @@ bool drm_exec_cleanup(struct drm_exec *exec)
> return true;
> }
>
> - drm_exec_unlock_all(exec);
> - exec->num_objects = 0;
> + exec->contended = NULL;
> return true;
> }
> EXPORT_SYMBOL(drm_exec_cleanup);
> @@ -194,6 +194,27 @@ static int drm_exec_lock_contended(struct drm_exec *exec)
> return ret;
> }
>
> +/**
> + * drm_exec_handle_contended() - Perform cleanup before a ww transaction restart
> + * @exec: Pointer to the drm_exec object.
> + *
> + * Unlocks all held resvs and re-locks the contended object.
> + *
> + * Return: 0 on success, negative error code on failure.
> + */
> +int drm_exec_handle_contended(struct drm_exec *exec)
> +{
> + int ret;
> +
> + drm_exec_unlock_all(exec);
> + exec->num_objects = 0;
> + ret = drm_exec_lock_contended(exec);
> + exec->contended = DRM_EXEC_CONTENDED;
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_exec_handle_contended);
> +
> /**
> * drm_exec_lock_obj - lock a GEM object for use
> * @exec: the drm_exec object with the state
> @@ -209,10 +230,6 @@ int drm_exec_lock_obj(struct drm_exec *exec, struct drm_gem_object *obj)
> {
> int ret;
>
> - ret = drm_exec_lock_contended(exec);
> - if (unlikely(ret))
> - return ret;
> -
> if (exec->prelocked == obj) {
> drm_gem_object_put(exec->prelocked);
> exec->prelocked = NULL;
> diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c
> index f9eb56f24bef..0923d6ae18e2 100644
> --- a/drivers/gpu/drm/drm_gpuvm.c
> +++ b/drivers/gpu/drm/drm_gpuvm.c
> @@ -1254,18 +1254,18 @@ drm_gpuvm_exec_lock(struct drm_gpuvm_exec *vm_exec)
>
> drm_exec_until_all_locked(exec) {
> ret = drm_gpuvm_prepare_vm(gpuvm, exec, num_fences);
> - drm_exec_retry_on_contention(exec);
> + ret = drm_exec_retry_on_contention(exec, ret);
> if (ret)
> goto err;
>
> ret = drm_gpuvm_prepare_objects(gpuvm, exec, num_fences);
> - drm_exec_retry_on_contention(exec);
> + ret = drm_exec_retry_on_contention(exec, ret);
> if (ret)
> goto err;
>
> if (vm_exec->extra.fn) {
> ret = vm_exec->extra.fn(vm_exec);
> - drm_exec_retry_on_contention(exec);
> + ret = drm_exec_retry_on_contention(exec, ret);
> if (ret)
> goto err;
> }
> @@ -1346,7 +1346,7 @@ drm_gpuvm_exec_lock_range(struct drm_gpuvm_exec *vm_exec,
> drm_exec_until_all_locked(exec) {
> ret = drm_gpuvm_prepare_range(gpuvm, exec, addr, range,
> vm_exec->num_fences);
> - drm_exec_retry_on_contention(exec);
> + ret = drm_exec_retry_on_contention(exec, ret);
> if (ret)
> goto err;
> }
> diff --git a/drivers/gpu/drm/imagination/pvr_job.c b/drivers/gpu/drm/imagination/pvr_job.c
> index 78c2f3c6dce0..6e0ce6c4576c 100644
> --- a/drivers/gpu/drm/imagination/pvr_job.c
> +++ b/drivers/gpu/drm/imagination/pvr_job.c
> @@ -574,7 +574,7 @@ prepare_job_resvs_for_each(struct drm_exec *exec, struct pvr_job_data *job_data,
> drm_exec_until_all_locked(exec) {
> int err = jobs_lock_all_objs(exec, job_data, job_count);
>
> - drm_exec_retry_on_contention(exec);
> + err = drm_exec_retry_on_contention(exec, err);
> if (err)
> return err;
> }
> diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
> index fba78193127d..01992b43ea4b 100644
> --- a/drivers/gpu/drm/msm/msm_gem_submit.c
> +++ b/drivers/gpu/drm/msm/msm_gem_submit.c
> @@ -259,7 +259,7 @@ static int submit_lock_objects(struct msm_gem_submit *submit)
> for (unsigned i = 0; i < submit->nr_bos; i++) {
> struct drm_gem_object *obj = submit->bos[i].obj;
> ret = drm_exec_prepare_obj(&submit->exec, obj, 1);
> - drm_exec_retry_on_contention(&submit->exec);
> + ret = drm_exec_retry_on_contention(&submit->exec, ret);
> if (ret)
> goto error;
> }
> diff --git a/drivers/gpu/drm/nouveau/nouveau_uvmm.c b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
> index ee02cd833c5e..0c871634fdfb 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
> @@ -1350,7 +1350,7 @@ nouveau_uvmm_bind_job_submit(struct nouveau_job *job,
> drm_exec_init(exec, vme->flags, 0);
> drm_exec_until_all_locked(exec) {
> ret = bind_lock_validate(job, exec, vme->num_fences);
> - drm_exec_retry_on_contention(exec);
> + ret = drm_exec_retry_on_contention(exec, ret);
> if (ret) {
> op = list_last_op(&bind_job->ops);
> goto unwind;
> diff --git a/drivers/gpu/drm/tests/drm_exec_test.c b/drivers/gpu/drm/tests/drm_exec_test.c
> index 81f928a429ba..28558fdb08df 100644
> --- a/drivers/gpu/drm/tests/drm_exec_test.c
> +++ b/drivers/gpu/drm/tests/drm_exec_test.c
> @@ -63,7 +63,7 @@ static void test_lock(struct kunit *test)
> drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
> drm_exec_until_all_locked(&exec) {
> ret = drm_exec_lock_obj(&exec, &gobj);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> KUNIT_EXPECT_EQ(test, ret, 0);
> if (ret)
> break;
> @@ -83,14 +83,14 @@ static void test_lock_unlock(struct kunit *test)
> drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
> drm_exec_until_all_locked(&exec) {
> ret = drm_exec_lock_obj(&exec, &gobj);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> KUNIT_EXPECT_EQ(test, ret, 0);
> if (ret)
> break;
>
> drm_exec_unlock_obj(&exec, &gobj);
> ret = drm_exec_lock_obj(&exec, &gobj);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> KUNIT_EXPECT_EQ(test, ret, 0);
> if (ret)
> break;
> @@ -110,13 +110,13 @@ static void test_duplicates(struct kunit *test)
> drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);
> drm_exec_until_all_locked(&exec) {
> ret = drm_exec_lock_obj(&exec, &gobj);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> KUNIT_EXPECT_EQ(test, ret, 0);
> if (ret)
> break;
>
> ret = drm_exec_lock_obj(&exec, &gobj);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> KUNIT_EXPECT_EQ(test, ret, 0);
> if (ret)
> break;
> @@ -137,7 +137,7 @@ static void test_prepare(struct kunit *test)
> drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
> drm_exec_until_all_locked(&exec) {
> ret = drm_exec_prepare_obj(&exec, &gobj, 1);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> KUNIT_EXPECT_EQ(test, ret, 0);
> if (ret)
> break;
> diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> index 040dd142c49c..20ec1ab1b52d 100644
> --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> @@ -200,7 +200,7 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)
> drm_exec_init(&exec, 0, 0);
> drm_exec_until_all_locked(&exec) {
> ret = xe_pf_begin(&exec, vma, atomic, tile->id);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> if (ret)
> goto unlock_dma_resv;
>
> @@ -543,7 +543,7 @@ static int handle_acc(struct xe_gt *gt, struct acc *acc)
> drm_exec_init(&exec, 0, 0);
> drm_exec_until_all_locked(&exec) {
> ret = xe_pf_begin(&exec, vma, true, tile->id);
> - drm_exec_retry_on_contention(&exec);
> + ret = drm_exec_retry_on_contention(&exec, ret);
> if (ret)
> break;
> }
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index e2ec148c9c33..335524e803e7 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -501,7 +501,7 @@ static void preempt_rebind_work_func(struct work_struct *w)
> bool done = false;
>
> err = xe_preempt_work_begin(&exec, vm, &done);
> - drm_exec_retry_on_contention(&exec);
> + err = drm_exec_retry_on_contention(&exec, err);
> if (err || done) {
> drm_exec_fini(&exec);
> if (err && xe_vm_validate_should_retry(&exec, err, &end))
> @@ -1052,7 +1052,7 @@ static void xe_vma_destroy_unlocked(struct xe_vma *vma)
> drm_exec_init(&exec, 0, 0);
> drm_exec_until_all_locked(&exec) {
> err = xe_vm_lock_vma(&exec, vma);
> - drm_exec_retry_on_contention(&exec);
> + err = drm_exec_retry_on_contention(&exec, err);
> if (XE_WARN_ON(err))
> break;
> }
> @@ -2148,11 +2148,11 @@ static struct xe_vma *new_vma(struct xe_vm *vm, struct drm_gpuva_op_map *op,
> err = 0;
> if (!bo->vm) {
> err = drm_exec_lock_obj(&exec, xe_vm_obj(vm));
> - drm_exec_retry_on_contention(&exec);
> + err = drm_exec_retry_on_contention(&exec, err);
> }
> if (!err) {
> err = drm_exec_lock_obj(&exec, &bo->ttm.base);
> - drm_exec_retry_on_contention(&exec);
> + err = drm_exec_retry_on_contention(&exec, err);
> }
> if (err) {
> drm_exec_fini(&exec);
> @@ -2884,7 +2884,7 @@ static int vm_bind_ioctl_ops_execute(struct xe_vm *vm,
> DRM_EXEC_IGNORE_DUPLICATES, 0);
> drm_exec_until_all_locked(&exec) {
> err = vm_bind_ioctl_ops_lock_and_prep(&exec, vm, vops);
> - drm_exec_retry_on_contention(&exec);
> + err = drm_exec_retry_on_contention(&exec, err);
> if (err)
> goto unlock;
>
> diff --git a/include/drm/drm_exec.h b/include/drm/drm_exec.h
> index aa786b828a0a..fafb40d96e38 100644
> --- a/include/drm/drm_exec.h
> +++ b/include/drm/drm_exec.h
> @@ -51,6 +51,8 @@ struct drm_exec {
> struct drm_gem_object *prelocked;
> };
>
> +int drm_exec_handle_contended(struct drm_exec *exec);
> +
> /**
> * drm_exec_obj() - Return the object for a give drm_exec index
> * @exec: Pointer to the drm_exec context
> @@ -113,15 +115,26 @@ __PASTE(__drm_exec_, __LINE__): \
> /**
> * drm_exec_retry_on_contention - restart the loop to grap all locks
> * @exec: drm_exec object
> + * @_ret: The current error status
> *
> * Control flow helper to continue when a contention was detected and we need to
> * clean up and re-start the loop to prepare all GEM objects.
> + *
> + * Return: If no loop restart occurred: The error status.
> */
> -#define drm_exec_retry_on_contention(exec) \
> - do { \
> - if (unlikely(drm_exec_is_contended(exec))) \
> - goto *__drm_exec_retry_ptr; \
> - } while (0)
> +#define drm_exec_retry_on_contention(exec, _ret) \
> + ({ \
> + struct drm_exec *__exec = (exec); \
> + int __ret = (_ret); \
> + \
> + if (unlikely(drm_exec_is_contended(__exec))) { \
> + WARN_ON(__ret != -EDEADLK); \
> + __ret = drm_exec_handle_contended(__exec); \
> + if (!__ret) \
> + goto *__drm_exec_retry_ptr; \
> + } \
> + __ret; \
> + })
>
> /**
> * drm_exec_is_contended - check for contention
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