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author | Tobias Burnus <tobias@codesourcery.com> | 2023-07-11 16:11:35 +0200 |
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committer | Tobias Burnus <tobias@codesourcery.com> | 2023-07-11 16:11:35 +0200 |
commit | 8c2fc744a25ec423ab1a317bf4e7d24315c40024 (patch) | |
tree | bbe8d7fad2d7af8c23e8b37e4918a27fd647d2c7 /libgomp/libgomp.texi | |
parent | b76d71564925abcabe6f5ad61d904b23c682cdfb (diff) | |
download | gcc-8c2fc744a25ec423ab1a317bf4e7d24315c40024.zip gcc-8c2fc744a25ec423ab1a317bf4e7d24315c40024.tar.gz gcc-8c2fc744a25ec423ab1a317bf4e7d24315c40024.tar.bz2 |
libgomp: Update OpenMP memory allocation doc, fix omp_high_bw_mem_space
libgomp/
* allocator.c (omp_init_allocator): Use malloc for
omp_high_bw_mem_space when the memkind lib is unavailable
instead of returning omp_null_allocator.
* libgomp.texi (OpenMP 5.0): Fix typo.
(Memory allocation with libmemkind): Document implementation
in more detail.
Diffstat (limited to 'libgomp/libgomp.texi')
-rw-r--r-- | libgomp/libgomp.texi | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/libgomp/libgomp.texi b/libgomp/libgomp.texi index 7d27cc5..d1a5e67 100644 --- a/libgomp/libgomp.texi +++ b/libgomp/libgomp.texi @@ -192,7 +192,7 @@ The OpenMP 4.5 specification is fully supported. env variable @tab Y @tab @item Nested-parallel changes to @var{max-active-levels-var} ICV @tab Y @tab @item @code{requires} directive @tab P - @tab complete but no non-host devices provides @code{unified_shared_memory} + @tab complete but no non-host device provides @code{unified_shared_memory} @item @code{teams} construct outside an enclosing target region @tab Y @tab @item Non-rectangular loop nests @tab P @tab Full support for C/C++, partial for Fortran @item @code{!=} as relational-op in canonical loop form for C/C++ @tab Y @tab @@ -4634,6 +4634,17 @@ smaller number. On non-host devices, the value of the @node Memory allocation with libmemkind @section Memory allocation with libmemkind +For the memory spaces, the following applies: +@itemize +@item @code{omp_default_mem_space} is supported +@item @code{omp_const_mem_space} maps to @code{omp_default_mem_space} +@item @code{omp_low_lat_mem_space} maps to @code{omp_default_mem_space} +@item @code{omp_large_cap_mem_space} maps to @code{omp_default_mem_space}, + unless the memkind library is available +@item @code{omp_high_bw_mem_space} maps to @code{omp_default_mem_space}, + unless the memkind library is available +@end itemize + On Linux systems, where the @uref{https://github.com/memkind/memkind, memkind library} (@code{libmemkind.so.0}) is available at runtime, it is used when creating memory allocators requesting @@ -4641,9 +4652,24 @@ creating memory allocators requesting @itemize @item the memory space @code{omp_high_bw_mem_space} @item the memory space @code{omp_large_cap_mem_space} -@item the partition trait @code{omp_atv_interleaved} +@item the partition trait @code{omp_atv_interleaved}; note that for + @code{omp_large_cap_mem_space} the allocation will not be interleaved @end itemize +Additional notes: +@itemize +@item The @code{pinned} trait is unsupported. +@item For the @code{partition} trait, the partition part size will be the same + as the requested size (i.e. @code{interleaved} or @code{blocked} has no + effect), except for @code{interleaved} when the memkind library is + available. Furthermore, for @code{nearest} the memory might not be + on the same NUMA node as thread that allocated the memory; on Linux, + this is in particular the case when the memory placement policy is + set to preferred. +@item The @code{access} trait has no effect such that memory is always + accessible by all threads. +@item The @code{sync_hint} trait has no effect. +@end itemize @c --------------------------------------------------------------------- @c Offload-Target Specifics |