linux-kernel - [PATCH v2 4/7] drm/amd: kill the outdated "Only the pthreads threading model is supported" checks

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Message-ID: <aXY_yLVHd63UlWtm@redhat.com>
Date: Sun, 25 Jan 2026 17:07:36 +0100
From: Oleg Nesterov <oleg@...hat.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Alice Ryhl <aliceryhl@...gle.com>,
	Boris Brezillon <boris.brezillon@...labora.com>,
	Christian König <christian.koenig@....com>,
	Felix Kuehling <felix.kuehling@....com>,
	Leon Romanovsky <leon@...nel.org>,
	Steven Price <steven.price@....com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>, linux-kernel@...r.kernel.org,
	amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
	linux-rdma@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH v2 4/7] drm/amd: kill the outdated "Only the pthreads
 threading model is supported" checks

Nowaday task->group_leader->mm != task->mm is only possible if
a) task is not a group leader and b) task->group_leader->mm == NULL
because task->group_leader has already exited using sys_exit().

I don't think that drm/amd tries to detect/nack this case.

Signed-off-by: Oleg Nesterov <oleg@...hat.com>
Reviewed-by: Christian König <christian.koenig@....com>
Acked-by: Felix Kuehling <felix.kuehling@....com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c   |  3 ---
 drivers/gpu/drm/amd/amdkfd/kfd_process.c | 10 ----------
 2 files changed, 13 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index a0f8ba382b9e..e44f158a11f0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2551,9 +2551,6 @@ void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
 	vm->task_info->task.pid = current->pid;
 	get_task_comm(vm->task_info->task.comm, current);
 
-	if (current->group_leader->mm != current->mm)
-		return;
-
 	vm->task_info->tgid = current->tgid;
 	get_task_comm(vm->task_info->process_name, current->group_leader);
 }
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index a085faac9fe1..f8ef18a3aa71 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -833,12 +833,6 @@ struct kfd_process *kfd_create_process(struct task_struct *thread)
 	if (!(thread->mm && mmget_not_zero(thread->mm)))
 		return ERR_PTR(-EINVAL);
 
-	/* Only the pthreads threading model is supported. */
-	if (thread->group_leader->mm != thread->mm) {
-		mmput(thread->mm);
-		return ERR_PTR(-EINVAL);
-	}
-
 	/* If the process just called exec(3), it is possible that the
 	 * cleanup of the kfd_process (following the release of the mm
 	 * of the old process image) is still in the cleanup work queue.
@@ -918,10 +912,6 @@ struct kfd_process *kfd_get_process(const struct task_struct *thread)
 	if (!thread->mm)
 		return ERR_PTR(-EINVAL);
 
-	/* Only the pthreads threading model is supported. */
-	if (thread->group_leader->mm != thread->mm)
-		return ERR_PTR(-EINVAL);
-
 	process = find_process(thread, false);
 	if (!process)
 		return ERR_PTR(-EINVAL);
-- 
2.52.0