[Bug 110481] performance hot issues in amdgpu_cs_ib_vm_chunk

https://bugs.freedesktop.org/show_bug.cgi?id=110481

--- Comment #1 from baopeng baopeng88_com@163.com --- performance hot stack:

start_thread -> impl_thrd_routine -> util_queue_thread_func -> amdgpu_cs_submit_ib -> amdgpu_cs_submit_raw -> drmCommandWriteRead -> ioctl -> el0_svc -> el0_svc_handler -> el0_svc_common -> __arm64_sys_ioctl -> ksys_ioctl -> do_vfs_ioctl -> amdgpu_drm_ioctl -> drm_ioctl -> drm_ioctl_kernel -> amdgpu_cs_ioctl -> amdgpu_bo_kmap-> ttm_bo_kmap -> vmap -> __get_vm_area_node -> alloc_vmap_area