From: Jonas Hahnfeld Date: Mon, 8 Aug 2016 10:08:14 +0000 (+0000) Subject: Do not block on explicit task depending on proxy task X-Git-Tag: llvmorg-4.0.0-rc1~13076 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bedc371c9da61289d82b18acbe5f7bb0fc1d9869;p=platform%2Fupstream%2Fllvm.git Do not block on explicit task depending on proxy task Consider the following code: int dep; #pragma omp target nowait depend(out: dep) { sleep(1); } #pragma omp task depend(in: dep) { printf("Task with dependency\n"); } printf("Doing some work...\n"); In its current state the runtime will block on the second task and not continue execution. Differential Revision: https://reviews.llvm.org/D23116 llvm-svn: 277992 --- diff --git a/openmp/runtime/src/kmp_taskdeps.cpp b/openmp/runtime/src/kmp_taskdeps.cpp index 1460f8d..76cd7bc 100644 --- a/openmp/runtime/src/kmp_taskdeps.cpp +++ b/openmp/runtime/src/kmp_taskdeps.cpp @@ -482,7 +482,8 @@ __kmpc_omp_task_with_deps( ident_t *loc_ref, kmp_int32 gtid, kmp_task_t * new_ta bool serial = current_task->td_flags.team_serial || current_task->td_flags.tasking_ser || current_task->td_flags.final; #if OMP_45_ENABLED - serial = serial && !(new_taskdata->td_flags.proxy == TASK_PROXY); + kmp_task_team_t * task_team = thread->th.th_task_team; + serial = serial && !(task_team && task_team->tt.tt_found_proxy_tasks); #endif if ( !serial && ( ndeps > 0 || ndeps_noalias > 0 )) { @@ -507,14 +508,8 @@ __kmpc_omp_task_with_deps( ident_t *loc_ref, kmp_int32 gtid, kmp_task_t * new_ta return TASK_CURRENT_NOT_QUEUED; } } else { -#if OMP_45_ENABLED - kmp_task_team_t * task_team = thread->th.th_task_team; - if ( task_team && task_team->tt.tt_found_proxy_tasks ) - __kmpc_omp_wait_deps ( loc_ref, gtid, ndeps, dep_list, ndeps_noalias, noalias_dep_list ); - else -#endif - KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d ignored dependencies for task (serialized)" - "loc=%p task=%p\n", gtid, loc_ref, new_taskdata ) ); + KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d ignored dependencies for task (serialized)" + "loc=%p task=%p\n", gtid, loc_ref, new_taskdata ) ); } KA_TRACE(10, ("__kmpc_omp_task_with_deps(exit): T#%d task had no blocking dependencies : " diff --git a/openmp/runtime/src/kmp_tasking.c b/openmp/runtime/src/kmp_tasking.c index ac9a25f..2dda197 100644 --- a/openmp/runtime/src/kmp_tasking.c +++ b/openmp/runtime/src/kmp_tasking.c @@ -622,6 +622,7 @@ __kmp_task_finish( kmp_int32 gtid, kmp_task_t *task, kmp_taskdata_t *resumed_tas { kmp_taskdata_t * taskdata = KMP_TASK_TO_TASKDATA(task); kmp_info_t * thread = __kmp_threads[ gtid ]; + kmp_task_team_t * task_team = thread->th.th_task_team; // might be NULL for serial teams... kmp_int32 children = 0; #if OMPT_SUPPORT @@ -678,6 +679,12 @@ __kmp_task_finish( kmp_int32 gtid, kmp_task_t *task, kmp_taskdata_t *resumed_tas #if OMP_40_ENABLED if ( taskdata->td_taskgroup ) KMP_TEST_THEN_DEC32( (kmp_int32 *)(& taskdata->td_taskgroup->count) ); +#if OMP_45_ENABLED + } + // if we found proxy tasks there could exist a dependency chain + // with the proxy task as origin + if ( !( taskdata -> td_flags.team_serial || taskdata -> td_flags.tasking_ser ) || (task_team && task_team->tt.tt_found_proxy_tasks) ) { +#endif __kmp_release_deps(gtid,taskdata); #endif } @@ -715,7 +722,11 @@ __kmp_task_finish( kmp_int32 gtid, kmp_task_t *task, kmp_taskdata_t *resumed_tas if (resumed_task == NULL) { resumed_task = taskdata->td_parent; // In a serialized task, the resumed task is the parent } - else { + else +#if OMP_45_ENABLED + if ( !(task_team && task_team->tt.tt_found_proxy_tasks) ) +#endif + { // verify resumed task passed in points to parent KMP_DEBUG_ASSERT( resumed_task == taskdata->td_parent ); } diff --git a/openmp/runtime/test/tasking/bug_proxy_task_dep_waiting.c b/openmp/runtime/test/tasking/bug_proxy_task_dep_waiting.c new file mode 100644 index 0000000..c61b828 --- /dev/null +++ b/openmp/runtime/test/tasking/bug_proxy_task_dep_waiting.c @@ -0,0 +1,131 @@ +// RUN: %libomp-compile -lpthread && %libomp-run +#include +#include +#include +#include "omp_my_sleep.h" + +/* + An explicit task can have a dependency on a target task. If it is not + directly satisfied, the runtime should not wait but resume execution. +*/ + +// Compiler-generated code (emulation) +typedef long kmp_intptr_t; +typedef int kmp_int32; + +typedef char bool; + +typedef struct ident { + kmp_int32 reserved_1; /**< might be used in Fortran; see above */ + kmp_int32 flags; /**< also f.flags; KMP_IDENT_xxx flags; KMP_IDENT_KMPC identifies this union member */ + kmp_int32 reserved_2; /**< not really used in Fortran any more; see above */ +#if USE_ITT_BUILD + /* but currently used for storing region-specific ITT */ + /* contextual information. */ +#endif /* USE_ITT_BUILD */ + kmp_int32 reserved_3; /**< source[4] in Fortran, do not use for C++ */ + char const *psource; /**< String describing the source location. + The string is composed of semi-colon separated fields which describe the source file, + the function and a pair of line numbers that delimit the construct. + */ +} ident_t; + +typedef struct kmp_depend_info { + kmp_intptr_t base_addr; + size_t len; + struct { + bool in:1; + bool out:1; + } flags; +} kmp_depend_info_t; + +struct kmp_task; +typedef kmp_int32 (* kmp_routine_entry_t)( kmp_int32, struct kmp_task * ); + +typedef struct kmp_task { /* GEH: Shouldn't this be aligned somehow? */ + void * shareds; /**< pointer to block of pointers to shared vars */ + kmp_routine_entry_t routine; /**< pointer to routine to call for executing task */ + kmp_int32 part_id; /**< part id for the task */ +} kmp_task_t; + +#ifdef __cplusplus +extern "C" { +#endif +kmp_int32 __kmpc_global_thread_num ( ident_t * ); +kmp_task_t* +__kmpc_omp_task_alloc( ident_t *loc_ref, kmp_int32 gtid, kmp_int32 flags, + size_t sizeof_kmp_task_t, size_t sizeof_shareds, + kmp_routine_entry_t task_entry ); +void __kmpc_proxy_task_completed_ooo ( kmp_task_t *ptask ); +kmp_int32 __kmpc_omp_task_with_deps ( ident_t *loc_ref, kmp_int32 gtid, kmp_task_t * new_task, + kmp_int32 ndeps, kmp_depend_info_t *dep_list, + kmp_int32 ndeps_noalias, kmp_depend_info_t *noalias_dep_list ); +kmp_int32 +__kmpc_omp_task( ident_t *loc_ref, kmp_int32 gtid, kmp_task_t * new_task ); +#ifdef __cplusplus +} +#endif + +void *target(void *task) +{ + my_sleep( 0.1 ); + __kmpc_proxy_task_completed_ooo((kmp_task_t*) task); + return NULL; +} + +pthread_t target_thread; + +// User's code +int task_entry(kmp_int32 gtid, kmp_task_t *task) +{ + pthread_create(&target_thread, NULL, &target, task); + return 0; +} + +int main() +{ + int dep; + +/* + * Corresponds to: + #pragma omp target nowait depend(out: dep) + { + my_sleep( 0.1 ); + } +*/ + kmp_depend_info_t dep_info; + dep_info.base_addr = (long) &dep; + dep_info.len = sizeof(int); + // out = inout per spec and runtime expects this + dep_info.flags.in = 1; + dep_info.flags.out = 1; + + kmp_int32 gtid = __kmpc_global_thread_num(NULL); + kmp_task_t *proxy_task = __kmpc_omp_task_alloc(NULL,gtid,17,sizeof(kmp_task_t),0,&task_entry); + __kmpc_omp_task_with_deps(NULL,gtid,proxy_task,1,&dep_info,0,NULL); + + int first_task_finished = 0; + #pragma omp task shared(first_task_finished) depend(inout: dep) + { + first_task_finished = 1; + } + + int second_task_finished = 0; + #pragma omp task shared(second_task_finished) depend(in: dep) + { + second_task_finished = 1; + } + + // check that execution has been resumed and the runtime has not waited + // for the dependencies to be satisfied. + int error = (first_task_finished == 1); + error += (second_task_finished == 1); + + #pragma omp taskwait + + // by now all tasks should have finished + error += (first_task_finished != 1); + error += (second_task_finished != 1); + + return error; +}