[Openmp-commits] [PATCH] D122667: llvm14 patch: hwloc include directory for libompd

[Bernhard Kaindl via Phabricator via Openmp-commits]

bernhardkaindl added a comment.

In D122667#3455056 <https://reviews.llvm.org/D122667#3455056>, @tianshilei1992 wrote:

> An add-up to this patch is, if both `ompd` and `omp` depend on `hwloc` (like including `hwloc` headers`), both should set `target_link_libraries`. The dependence should be:
>
>   omp---->hwloc
>            ^
>   ompd-----|
>
> The transitive dependence is bad practice.

The dependency at the build failure is: 
openmp/libompd/src/omp-icv.cpp:21:
-> openmp/runtime/src/kmp.h:96:
--> #include "hwloc.h"

The size of struct dispatch_shared_info / dispatch_shared_info_t depends on if #KMP_USE_HWLOC is set, from `openmp/runtime/src/kmp.h`

  #if KMP_USE_HWLOC
    // When linking with libhwloc, the ORDERED EPCC test slows down on big
    // machines (> 48 cores). Performance analysis showed that a cache thrash
    // was occurring and this padding helps alleviate the problem.
    char padding[64];
  #endif
  } dispatch_shared_info_t;

ompd does not appear to use seems to use hwloc-related directly, but I'd say risking to break code just to avoid the include path in libompd does not appear to be worth any breakage.

I uploaded my revision as https://reviews.llvm.org/D123888


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