From 4a75460b0099618b2d79ffda615a9516dcd5c224 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Wed, 23 Jan 2019 08:16:56 +0000 Subject: [PATCH] [nvptx, libgomp] Fix cuMemAlloc with size zero Consider test-case: ... int main (void) { #pragma acc parallel async ; #pragma acc parallel async ; #pragma acc wait return 0; } ... This fails with: ... libgomp: cuMemAlloc error: invalid argument Segmentation fault (core dumped) ... The cuMemAlloc error is due to the fact that we're try to allocate 0 bytes. Fix this by preventing calling map_push with size zero argument in nvptx_exec. This also has the consequence that for the abort-1.c test-case, we end up calling cuMemFree during map_fini for the struct cuda_map allocated in map_init, which fails because an abort happened. Fix this by calling cuMemFree with CUDA_CALL_NOCHECK in cuda_map_destroy. 2019-01-23 Tom de Vries PR target/PR88946 * plugin/plugin-nvptx.c (cuda_map_destroy): Use CUDA_CALL_NOCHECK for cuMemFree. (nvptx_exec): Don't call map_push if mapnum == 0. * testsuite/libgomp.oacc-c-c++-common/pr88946.c: New test. From-SVN: r268178 --- libgomp/ChangeLog | 8 ++++ libgomp/plugin/plugin-nvptx.c | 48 +++++++++++++--------- .../testsuite/libgomp.oacc-c-c++-common/pr88946.c | 15 +++++++ 3 files changed, 51 insertions(+), 20 deletions(-) create mode 100644 libgomp/testsuite/libgomp.oacc-c-c++-common/pr88946.c diff --git a/libgomp/ChangeLog b/libgomp/ChangeLog index 30fb11d..660fc92 100644 --- a/libgomp/ChangeLog +++ b/libgomp/ChangeLog @@ -1,5 +1,13 @@ 2019-01-23 Tom de Vries + PR target/PR88946 + * plugin/plugin-nvptx.c (cuda_map_destroy): Use CUDA_CALL_NOCHECK for + cuMemFree. + (nvptx_exec): Don't call map_push if mapnum == 0. + * testsuite/libgomp.oacc-c-c++-common/pr88946.c: New test. + +2019-01-23 Tom de Vries + PR target/88941 PR target/88939 * plugin/plugin-nvptx.c (cuda_map_destroy): Handle map->active case. diff --git a/libgomp/plugin/plugin-nvptx.c b/libgomp/plugin/plugin-nvptx.c index 4a67191..ff90b67 100644 --- a/libgomp/plugin/plugin-nvptx.c +++ b/libgomp/plugin/plugin-nvptx.c @@ -260,7 +260,7 @@ cuda_map_destroy (struct cuda_map *map) atexit handler (PR83795). */ ; else - CUDA_CALL_ASSERT (cuMemFree, map->d); + CUDA_CALL_NOCHECK (cuMemFree, map->d); free (map); } @@ -1164,7 +1164,7 @@ nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs, struct ptx_stream *dev_str; void *kargs[1]; void *hp; - CUdeviceptr dp; + CUdeviceptr dp = 0; struct nvptx_thread *nvthd = nvptx_thread (); int warp_size = nvthd->ptx_dev->warp_size; const char *maybe_abort_msg = "(perhaps abort was called)"; @@ -1361,23 +1361,27 @@ nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs, dims[GOMP_DIM_VECTOR]); } - /* This reserves a chunk of a pre-allocated page of memory mapped on both - the host and the device. HP is a host pointer to the new chunk, and DP is - the corresponding device pointer. */ - pthread_mutex_lock (&ptx_event_lock); - dp = map_push (dev_str, mapnum * sizeof (void *)); - pthread_mutex_unlock (&ptx_event_lock); - - GOMP_PLUGIN_debug (0, " %s: prepare mappings\n", __FUNCTION__); - - /* Copy the array of arguments to the mapped page. */ - hp = alloca(sizeof(void *) * mapnum); - for (i = 0; i < mapnum; i++) - ((void **) hp)[i] = devaddrs[i]; + if (mapnum > 0) + { + /* This reserves a chunk of a pre-allocated page of memory mapped on both + the host and the device. HP is a host pointer to the new chunk, and DP is + the corresponding device pointer. */ + pthread_mutex_lock (&ptx_event_lock); + dp = map_push (dev_str, mapnum * sizeof (void *)); + pthread_mutex_unlock (&ptx_event_lock); + + GOMP_PLUGIN_debug (0, " %s: prepare mappings\n", __FUNCTION__); + + /* Copy the array of arguments to the mapped page. */ + hp = alloca(sizeof(void *) * mapnum); + for (i = 0; i < mapnum; i++) + ((void **) hp)[i] = devaddrs[i]; + + /* Copy the (device) pointers to arguments to the device */ + CUDA_CALL_ASSERT (cuMemcpyHtoD, dp, hp, + mapnum * sizeof (void *)); + } - /* Copy the (device) pointers to arguments to the device */ - CUDA_CALL_ASSERT (cuMemcpyHtoD, dp, hp, - mapnum * sizeof (void *)); GOMP_PLUGIN_debug (0, " %s: kernel %s: launch" " gangs=%u, workers=%u, vectors=%u\n", __FUNCTION__, targ_fn->launch->fn, dims[GOMP_DIM_GANG], @@ -1422,7 +1426,8 @@ nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs, CUDA_CALL_ASSERT (cuEventRecord, *e, dev_str->stream); - event_add (PTX_EVT_KNL, e, (void *)dev_str, 0); + if (mapnum > 0) + event_add (PTX_EVT_KNL, e, (void *)dev_str, 0); } #else r = CUDA_CALL_NOCHECK (cuCtxSynchronize, ); @@ -1439,7 +1444,10 @@ nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs, #ifndef DISABLE_ASYNC if (async < acc_async_noval) #endif - map_pop (dev_str); + { + if (mapnum > 0) + map_pop (dev_str); + } } void * openacc_get_current_cuda_context (void); diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/pr88946.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/pr88946.c new file mode 100644 index 0000000..ad56ded --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/pr88946.c @@ -0,0 +1,15 @@ +/* { dg-do run } */ + +int +main (void) +{ + #pragma acc parallel async + ; + + #pragma acc parallel async + ; + + #pragma acc wait + + return 0; +} -- 2.7.4