Hi, Thomas!
Is this change ok for OpenACC/PTX?
On Mon, Apr 20, 2015 at 17:16:03 +0300, Ilya Verbin wrote:
> Currently if a compiler is configured with enabled offloading, the 'devices'
> array in libgomp is filled properly with a number of available devices.
> However, if a program is compiled with -foffload=disable, the resolve_device
> function returns a pointer to the device, and host-fallback is not happening.
> The patch below fixes this issue.
> make check-target-libgomp passed. OK for trunk?
>
>
> libgomp/
> * libgomp.h (struct gomp_device_descr): Add num_images.
> * target.c (resolve_device): Call gomp_init_device. Return NULL if
> there is no image loaded to the device.
> (gomp_offload_image_to_device): Increase num_images.
> (GOMP_offload_unregister): Decrease num_images.
> (GOMP_target): Don't call gomp_init_device.
> (GOMP_target_data): Ditto.
> (GOMP_target_update): Ditto.
> (gomp_target_init): Set num_images to 0.
> * testsuite/libgomp.c/target-1-disable.c: New test.
>
>
> diff --git a/libgomp/libgomp.h b/libgomp/libgomp.h
> index 5272f01..47a064a 100644
> --- a/libgomp/libgomp.h
> +++ b/libgomp/libgomp.h
> @@ -762,6 +762,9 @@ struct gomp_device_descr
> /* Set to true when device is initialized. */
> bool is_initialized;
>
> + /* Number of images offloaded to the device. */
> + int num_images;
> +
> /* OpenACC-specific data and functions. */
> /* This is mutable because of its mutable data_environ and target_data
> members. */
> diff --git a/libgomp/target.c b/libgomp/target.c
> index d8da783..f5126b9 100644
> --- a/libgomp/target.c
> +++ b/libgomp/target.c
> @@ -132,6 +132,14 @@ resolve_device (int device_id)
> if (device_id < 0 || device_id >= gomp_get_num_devices ())
> return NULL;
>
> + gomp_mutex_lock (&devices[device_id].lock);
> + if (!devices[device_id].is_initialized)
> + gomp_init_device (&devices[device_id]);
> + gomp_mutex_unlock (&devices[device_id].lock);
> +
> + if (devices[device_id].num_images <= 0)
> + return NULL;
> +
> return &devices[device_id];
> }
>
> @@ -697,6 +705,7 @@ gomp_offload_image_to_device (struct gomp_device_descr
> *devicep,
> struct addr_pair *target_table = NULL;
> int i, num_target_entries
> = devicep->load_image_func (devicep->target_id, target_data,
> &target_table);
> + devicep->num_images++;
>
> if (num_target_entries != num_funcs + num_vars)
> {
> @@ -831,6 +840,7 @@ GOMP_offload_unregister (void *host_table, enum
> offload_target_type target_type,
> }
>
> devicep->unload_image_func (devicep->target_id, target_data);
> + devicep->num_images--;
>
> /* Remove mapping from splay tree. */
> struct splay_tree_key_s k;
> @@ -966,11 +976,6 @@ GOMP_target (int device, void (*fn) (void *), const void
> *unused,
> return;
> }
>
> - gomp_mutex_lock (&devicep->lock);
> - if (!devicep->is_initialized)
> - gomp_init_device (devicep);
> - gomp_mutex_unlock (&devicep->lock);
> -
> void *fn_addr;
>
> if (devicep->capabilities & GOMP_OFFLOAD_CAP_NATIVE_EXEC)
> @@ -1034,11 +1039,6 @@ GOMP_target_data (int device, const void *unused,
> size_t mapnum,
> return;
> }
>
> - gomp_mutex_lock (&devicep->lock);
> - if (!devicep->is_initialized)
> - gomp_init_device (devicep);
> - gomp_mutex_unlock (&devicep->lock);
> -
> struct target_mem_desc *tgt
> = gomp_map_vars (devicep, mapnum, hostaddrs, NULL, sizes, kinds, false,
> false);
> @@ -1069,11 +1069,6 @@ GOMP_target_update (int device, const void *unused,
> size_t mapnum,
> || !(devicep->capabilities & GOMP_OFFLOAD_CAP_OPENMP_400))
> return;
>
> - gomp_mutex_lock (&devicep->lock);
> - if (!devicep->is_initialized)
> - gomp_init_device (devicep);
> - gomp_mutex_unlock (&devicep->lock);
> -
> gomp_update (devicep, mapnum, hostaddrs, sizes, kinds, false);
> }
>
> @@ -1265,6 +1260,7 @@ gomp_target_init (void)
> current_device.type = current_device.get_type_func ();
> current_device.mem_map.root = NULL;
> current_device.is_initialized = false;
> + current_device.num_images = 0;
> current_device.openacc.data_environ = NULL;
> for (i = 0; i < new_num_devices; i++)
> {
> diff --git a/libgomp/testsuite/libgomp.c/target-1-disable.c
> b/libgomp/testsuite/libgomp.c/target-1-disable.c
> new file mode 100644
> index 0000000..00ea143
> --- /dev/null
> +++ b/libgomp/testsuite/libgomp.c/target-1-disable.c
> @@ -0,0 +1,4 @@
> +/* { dg-options "-foffload=disable" } */
> +/* { dg-require-effective-target offload_device } */
> +
> +#include "target-1.c"
-- Ilya
