replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fix hwloc topology traversal code unable to handle situation where L2 cache is common for the packages 

Currently cores within package that share the same L2 cache are grouped together.
The current logic behind this assumes that the L2 cache is always at deeper
(or the same) level than the package itself. In case when L2 cache is common
for all packages (and the packages are at deeper level than L2 cache) the whole of
the further topology discovery fails to find any computational units resulting in
following assertion:

Assertion failure at kmp_affinity.cpp(715): nActiveThreads == __kmp_avail_proc.
OMP: Error #13: Assertion failure at kmp_affinity.cpp(715).

This patch adds a bit of a logic that prevents such situation from occurring.

Differential Revision: https://reviews.llvm.org/D61796

llvm-svn: 360890
This commit is contained in:
Paul Osmialowski 2019-05-16 13:16:24 +00:00
parent 73643b5041
commit 0732fcc7d5
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
openmp/runtime/src/kmp_affinity.cpp
View File

@ -530,7 +530,7 @@ static int __kmp_hwloc_process_obj_core_pu(AddrUnsPair *addrPair,
static int __kmp_hwloc_check_numa() {
hwloc_topology_t &tp = __kmp_hwloc_topology;
hwloc_obj_t hT, hC, hL, hN, hS; // hwloc objects (pointers to)
int depth;
int depth, l2cache_depth, package_depth;
// Get some PU
hT = hwloc_get_obj_by_type(tp, HWLOC_OBJ_PU, 0);
@ -548,8 +548,10 @@ static int __kmp_hwloc_check_numa() {
}
}
package_depth = hwloc_get_type_depth(tp, HWLOC_OBJ_PACKAGE);
l2cache_depth = hwloc_get_cache_type_depth(tp, 2, HWLOC_OBJ_CACHE_UNIFIED);
// check tile, get object by depth because of multiple caches possible
depth = hwloc_get_cache_type_depth(tp, 2, HWLOC_OBJ_CACHE_UNIFIED);
depth = (l2cache_depth < package_depth) ? package_depth : l2cache_depth;
hL = hwloc_get_ancestor_obj_by_depth(tp, depth, hT);
hC = NULL; // not used, but reset it here just in case
if (hL != NULL &&