Re: [rcu:dev.2019.03.20b 54/83] drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_process.c:50:1: error: type defaults to 'int' in declaration of 'DEFINE_SRCU'

[Rong Chen <rong.a.chen@intel.com>]

On 3/28/19 3:57 AM, Paul E. McKenney wrote:
> On Mon, Mar 25, 2019 at 02:34:27AM +0800, kbuild test robot wrote:
>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2019.03.20b
>> head:   6d4434b4b4df791620743178e1419de882b44c7b
>> commit: eb89abcb30733e3a2343dda23cb6d81cc17c60b3 [54/83] rcu: Forbid DEFINE{,_STATIC}_SRCU() from modules
>> config: x86_64-randconfig-b0-03250021 (attached as .config)
>> compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
>> reproduce:
>>          git checkout eb89abcb30733e3a2343dda23cb6d81cc17c60b3
>>          # save the attached .config to linux build tree
>>          make ARCH=x86_64
>>
>> All errors (new ones prefixed by >>):
>>
>>     drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_process.c:50:1: warning: data definition has no type or storage class
>>      DEFINE_SRCU(kfd_processes_srcu);
>>      ^~~~~~~~~~~
>>>> drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_process.c:50:1: error: type defaults to 'int' in declaration of 'DEFINE_SRCU' [-Werror=implicit-int]
>>     drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_process.c:50:1: warning: parameter names (without types) in function declaration
>>     cc1: some warnings being treated as errors
> I don't have that hardware, but does the following help?  (It at least
> builds for me, but your mileage may vary.)
>
> 							Thanx, Paul

Yes, the patch works for kbuild robot.

Thanks,
Rong Chen


>
> ------------------------------------------------------------------------
>
> commit b30be5a76070402912437fa23b43de11cb1973f4
> Author: Paul E. McKenney <paulmck@linux.ibm.com>
> Date:   Wed Mar 27 12:53:36 2019 -0700
>
>      drivers/gpu/drm/amd: Dynamically allocate kfd_processes_srcu
>      
>      Having DEFINE_SRCU() or DEFINE_STATIC_SRCU() in a loadable module
>      requires that the size of the reserved region be increased, which is
>      not something we really want to be doing.  This commit therefore removes
>      the DEFINE_STATIC_SRCU() from drivers/gpu/drm/amd/amdkfd/kfd_process.c in
>      favor of defining kfd_processes_srcu as a simple srcu_struct, initializing
>      it in amdgpu_amdkfd_init(), and cleaning it up in amdgpu_amdkfd_fini().
>      
>      Reported-by: kbuild test robot <lkp@intel.com>
>      Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
>      Cc: Oded Gabbay <oded.gabbay@gmail.com>
>      Cc: Alex Deucher <alexander.deucher@amd.com>
>      Cc: "Christian König" <christian.koenig@amd.com
>      Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
>      Cc: David Airlie <airlied@linux.ie>
>      Cc: Daniel Vetter <daniel@ffwll.ch>
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> index fe1d7368c1e6..eadb20dee867 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
> @@ -28,6 +28,8 @@
>   #include <linux/module.h>
>   #include <linux/dma-buf.h>
>   
> +extern struct srcu_struct kfd_processes_srcu;
> +
>   static const unsigned int compute_vmid_bitmap = 0xFF00;
>   
>   /* Total memory size in system memory and all GPU VRAM. Used to
> @@ -40,6 +42,8 @@ int amdgpu_amdkfd_init(void)
>   	struct sysinfo si;
>   	int ret;
>   
> +	ret = init_srcu_struct(&kfd_processes_srcu);
> +	WARN_ON(ret);
>   	si_meminfo(&si);
>   	amdgpu_amdkfd_total_mem_size = si.totalram - si.totalhigh;
>   	amdgpu_amdkfd_total_mem_size *= si.mem_unit;
> @@ -57,6 +61,7 @@ int amdgpu_amdkfd_init(void)
>   void amdgpu_amdkfd_fini(void)
>   {
>   	kgd2kfd_exit();
> +	cleanup_srcu_struct(&kfd_processes_srcu);
>   }
>   
>   void amdgpu_amdkfd_device_probe(struct amdgpu_device *adev)
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> index 4bdae78bab8e..98b694068b8a 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> @@ -47,7 +47,7 @@ struct mm_struct;
>   DEFINE_HASHTABLE(kfd_processes_table, KFD_PROCESS_TABLE_SIZE);
>   static DEFINE_MUTEX(kfd_processes_mutex);
>   
> -DEFINE_SRCU(kfd_processes_srcu);
> +struct srcu_struct kfd_processes_srcu;
>   
>   /* For process termination handling */
>   static struct workqueue_struct *kfd_process_wq;
>