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| author | Jonathan Peyton <jonathan.l.peyton@intel.com> | 2016-05-31 19:01:15 +0000 |
|---|---|---|
| committer | Jonathan Peyton <jonathan.l.peyton@intel.com> | 2016-05-31 19:01:15 +0000 |
| commit | 067325f935e3d43d4b2b6e2dbe122ba6daf35359 (patch) | |
| tree | 641cf5b938352eaf9dc44bc91ca2e40a588ecfcc /openmp/runtime/src/kmp_ftn_os.h | |
| parent | 96ef87e9105ad1cecd72981eaf970982f66b3725 (diff) | |
| download | bcm5719-llvm-067325f935e3d43d4b2b6e2dbe122ba6daf35359.tar.gz bcm5719-llvm-067325f935e3d43d4b2b6e2dbe122ba6daf35359.zip | |
Offer API for setting number of loop dispatch buffers
The problem is the lack of dispatch buffers when thousands of loops with nowait,
about 10 iterations each, are executed by hundreds of threads. We only have
built-in 7 dispatch buffers, but there is a need in dozens or hundreds of
buffers.
The problem can be fixed by setting KMP_MAX_DISP_BUF to bigger value. In order
to give users same possibility I changed build-time control into run-time one,
adding API just in case.
This change adds an environment variable KMP_DISP_NUM_BUFFERS and a new API
function kmp_set_disp_num_buffers(int num_buffers).
The KMP_DISP_NUM_BUFFERS envirable works only before serial initialization,
because during the serial initialization we already allocate buffers for the hot
team, so it is too late to change the number of buffers later (or we need to
reallocate buffers for all teams which sounds too complicated). The
kmp_set_defaults() routine does not work for this envirable, because it calls
serial initialization before reading the parameter string. So a new routine,
kmp_set_disp_num_buffers(), is created so that it can set our internal global
variable before the library initialization. If both the envirable and API used
the envirable wins.
Differential Revision: http://reviews.llvm.org/D20697
llvm-svn: 271318
Diffstat (limited to 'openmp/runtime/src/kmp_ftn_os.h')
| -rw-r--r-- | openmp/runtime/src/kmp_ftn_os.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/openmp/runtime/src/kmp_ftn_os.h b/openmp/runtime/src/kmp_ftn_os.h index 6dece35b573..04b455145f4 100644 --- a/openmp/runtime/src/kmp_ftn_os.h +++ b/openmp/runtime/src/kmp_ftn_os.h @@ -35,6 +35,7 @@ #define FTN_SET_LIBRARY kmp_set_library #define FTN_GET_LIBRARY kmp_get_library #define FTN_SET_DEFAULTS kmp_set_defaults + #define FTN_SET_DISP_NUM_BUFFERS kmp_set_disp_num_buffers #define FTN_SET_AFFINITY kmp_set_affinity #define FTN_GET_AFFINITY kmp_get_affinity #define FTN_GET_AFFINITY_MAX_PROC kmp_get_affinity_max_proc @@ -152,6 +153,7 @@ #define FTN_SET_LIBRARY kmp_set_library_ #define FTN_GET_LIBRARY kmp_get_library_ #define FTN_SET_DEFAULTS kmp_set_defaults_ + #define FTN_SET_DISP_NUM_BUFFERS kmp_set_disp_num_buffers_ #define FTN_SET_AFFINITY kmp_set_affinity_ #define FTN_GET_AFFINITY kmp_get_affinity_ #define FTN_GET_AFFINITY_MAX_PROC kmp_get_affinity_max_proc_ @@ -270,6 +272,7 @@ #define FTN_SET_LIBRARY KMP_SET_LIBRARY #define FTN_GET_LIBRARY KMP_GET_LIBRARY #define FTN_SET_DEFAULTS KMP_SET_DEFAULTS + #define FTN_SET_DISP_NUM_BUFFERS KMP_SET_DISP_NUM_BUFFERS #define FTN_SET_AFFINITY KMP_SET_AFFINITY #define FTN_GET_AFFINITY KMP_GET_AFFINITY #define FTN_GET_AFFINITY_MAX_PROC KMP_GET_AFFINITY_MAX_PROC @@ -388,6 +391,7 @@ #define FTN_SET_LIBRARY KMP_SET_LIBRARY_ #define FTN_GET_LIBRARY KMP_GET_LIBRARY_ #define FTN_SET_DEFAULTS KMP_SET_DEFAULTS_ + #define FTN_SET_DISP_NUM_BUFFERS KMP_SET_DISP_NUM_BUFFERS_ #define FTN_SET_AFFINITY KMP_SET_AFFINITY_ #define FTN_GET_AFFINITY KMP_GET_AFFINITY_ #define FTN_GET_AFFINITY_MAX_PROC KMP_GET_AFFINITY_MAX_PROC_ |
