Re: [PATCH RFC tip/core/rcu 3/4] drivers/gpu/drm/amd: Dynamically allocate kfd_processes_srcu
From: Kuehling, Felix
Date: Tue Apr 02 2019 - 13:41:03 EST
On 2019-04-02 10:29 a.m., Paul E. McKenney wrote:
> 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@xxxxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
> Tested-by: kbuild test robot <lkp@xxxxxxxxx>
> Cc: Oded Gabbay <oded.gabbay@xxxxxxxxx>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: "Christian KÃnig" <christian.koenig@xxxxxxx
> Cc: "David (ChunMing) Zhou" <David1.Zhou@xxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: <dri-devel@xxxxxxxxxxxxxxxxxxxxx>
> Cc: <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 5 +++++
> drivers/gpu/drm/amd/amdkfd/kfd_process.c | 2 +-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> 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);
kfd_processes_srcu only exists if kfd_process.c is compiled in. That
depends on CONFIG_HSA_AMD. So this should at least move into #ifdef a
few lines below.
However, it would be cleaner to move this initialization into kfd_init
in kfd_module.c, or better yet, into kfd_process_create_wq in
kfd_process.c. Then kfd_process_create_wq should be renamed to something
more generic, such as kfd_process_init.
> 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);
Similarly, this would be cleaner in kfd_exit in kfd_module.c or
kfd_process_destroy_wq in kfd_process.c, with that function similarly
renamed to kfd_process_fini.
I'm attaching a revised patch. It's only compile tested.
Regards,
 Felix
> }
>
> 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;
From 5857a9aa63957a5755ff81ae5c46533bca408c12 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx>
Date: Tue, 2 Apr 2019 07:29:32 -0700
Subject: [PATCH 1/1] drivers/gpu/drm/amd: Dynamically allocate
kfd_processes_srcu v2
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
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 kfd_process_init(), and cleaning it up in kfd_process_fini().
v2 (Felix Kuehling): Move srcu init and cleanup into kfd_process.c
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Tested-by (v1): kbuild test robot <lkp@xxxxxxxxx>
Cc: Oded Gabbay <oded.gabbay@xxxxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: "Christian König" <christian.koenig@xxxxxxx>
Cc: "David (ChunMing) Zhou" <David1.Zhou@xxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: <dri-devel@xxxxxxxxxxxxxxxxxxxxx>
Cc: <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_module.c | 8 ++++----
drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 4 ++--
drivers/gpu/drm/amd/amdkfd/kfd_process.c | 19 ++++++++++++-------
3 files changed, 18 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_module.c b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
index 932007e..e8e2c15 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_module.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
@@ -52,15 +52,15 @@ static int kfd_init(void)
if (err < 0)
goto err_topology;
- err = kfd_process_create_wq();
+ err = kfd_process_init();
if (err < 0)
- goto err_create_wq;
+ goto err_process;
kfd_debugfs_init();
return 0;
-err_create_wq:
+err_process:
kfd_topology_shutdown();
err_topology:
kfd_chardev_exit();
@@ -71,7 +71,7 @@ static int kfd_init(void)
static void kfd_exit(void)
{
kfd_debugfs_fini();
- kfd_process_destroy_wq();
+ kfd_process_fini();
kfd_topology_shutdown();
kfd_chardev_exit();
}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index 9e02309..9dd187c 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -708,8 +708,8 @@ struct amdkfd_ioctl_desc {
};
bool kfd_dev_is_large_bar(struct kfd_dev *dev);
-int kfd_process_create_wq(void);
-void kfd_process_destroy_wq(void);
+int kfd_process_init(void);
+void kfd_process_fini(void);
struct kfd_process *kfd_create_process(struct file *filep);
struct kfd_process *kfd_get_process(const struct task_struct *);
struct kfd_process *kfd_lookup_process_by_pasid(unsigned int pasid);
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index 4bdae78..f810911 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;
@@ -69,22 +69,25 @@ static void evict_process_worker(struct work_struct *work);
static void restore_process_worker(struct work_struct *work);
-int kfd_process_create_wq(void)
+int kfd_process_init(void)
{
+ int ret;
+
if (!kfd_process_wq)
kfd_process_wq = alloc_workqueue("kfd_process_wq", 0, 0);
if (!kfd_restore_wq)
kfd_restore_wq = alloc_ordered_workqueue("kfd_restore_wq", 0);
- if (!kfd_process_wq || !kfd_restore_wq) {
- kfd_process_destroy_wq();
+ if (!kfd_process_wq || !kfd_restore_wq)
return -ENOMEM;
- }
- return 0;
+ ret = init_srcu_struct(&kfd_processes_srcu);
+ WARN_ON(ret);
+
+ return ret;
}
-void kfd_process_destroy_wq(void)
+void kfd_process_fini(void)
{
if (kfd_process_wq) {
destroy_workqueue(kfd_process_wq);
@@ -94,6 +97,8 @@ void kfd_process_destroy_wq(void)
destroy_workqueue(kfd_restore_wq);
kfd_restore_wq = NULL;
}
+
+ cleanup_srcu_struct(&kfd_processes_srcu);
}
static void kfd_process_free_gpuvm(struct kgd_mem *mem,
--
2.7.4