http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55411
Bug #: 55411
Summary: OMP threads lose their OMP_WAIT_POLICY when another
OMP thread gets destructed
Classification: Unclassified
Product: gcc
Version: 4.6.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgomp
AssignedTo: [email protected]
ReportedBy: [email protected]
So there are 2 bugs:
* the omp workers of a boost::thread are ignoring OMP_WAIT_POLICY
* once the boost::thread gets destructed the main-thread's omp worker's
WAIT_POLICY get lost
used to compile the example:
g++ -fopenmp -lgomp -lboost_system -lboost_thread-mt -o foo.bin -O2 foo_omp.c
tested with gentoo:
Just run the example with `export OMP_WAIT_POLICY="ACTIVE"` and watch it in
another window with htop. First all created omp threads use 100%, then the
boost::thread and its omp workers are spawned (all with ~0% cpu usage, still
the main-thread's omp workers use 100%). Then the boost::thread gets destructed
and the main-threads omp workers fallback to 0% cpu usage.
PS: It would be nice if there was a GOMP_DEBUG to enable a more verbose output,
esp. to debug GOMP_SPINCOUNT & OMP_PROC_BIND.
