Date: Sun, 17 May 2009 07:51:19 GMT From: Mikolaj Golub <to.my.trociny@gmail.com> To: freebsd-gnats-submit@FreeBSD.org Subject: gnu/134604: Memory leak in gcclibs/libgomp Message-ID: <200905170751.n4H7pJ9B009456@www.freebsd.org> Resent-Message-ID: <200905170800.n4H80867019834@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
>Number: 134604
>Category: gnu
>Synopsis: Memory leak in gcclibs/libgomp
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sun May 17 08:00:07 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator: Mikolaj Golub
>Release:
>Organization:
>Environment:
>Description:
#include <omp.h>
int n = 4, m = 2;
int main () {
for (;;) {
int i;
#pragma omp parallel for num_threads(m)
for(i = 0; i < 1; i++) {}
#pragma omp parallel for num_threads(n)
for(i = 0; i < 1; i++) {}
}
return 0;
}
When run on freebsd, this test shows constant growth of virtual memory usage.
Memory growth is observed only when m != n.
There is some discussion of this problem on freebsd-hackers:
http://lists.freebsd.org/pipermail/freebsd-hackers/2009-May/028552.html
The problem has also been reported to gcc mainstream:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40174
>How-To-Repeat:
Compile the test shown above with -fopenmp and run.
>Fix:
The problem is in libgomp/team.c. gomp_thread_start() does sem_init()
but sem_destroy() is never called.
Attached patch solves the problem for me.
Patch attached with submission follows:
--- contrib/gcclibs/libgomp/team.c.orig 2009-05-16 17:32:57.000000000 +0300
+++ contrib/gcclibs/libgomp/team.c 2009-05-16 19:16:37.000000000 +0300
@@ -164,9 +164,12 @@ new_team (unsigned nthreads, struct gomp
static void
free_team (struct gomp_team *team)
{
+ int i;
free (team->work_shares);
gomp_mutex_destroy (&team->work_share_lock);
gomp_barrier_destroy (&team->barrier);
+ for(i = 1; i < team->nthreads; i++)
+ gomp_sem_destroy (team->ordered_release[i]);
gomp_sem_destroy (&team->master_release);
free (team);
}
>Release-Note:
>Audit-Trail:
>Unformatted:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200905170751.n4H7pJ9B009456>