On 2018/12/13 11:51 PM, Thomas Schwinge wrote:
On Thu, 13 Dec 2018 23:28:49 +0800, Chung-Lin Tang<chunglin_t...@mentor.com>
wrote:
On 2018/12/7 6:26 AM, Julian Brown wrote:
On Thu, 6 Dec 2018 22:22:46 +0000
Julian Brown<jul...@codesourcery.com> wrote:
On Thu, 6 Dec 2018 21:42:14 +0100
Thomas Schwinge<tho...@codesourcery.com> wrote:
[...]
..., where the "Invalid read of size 8" happens, and which
eventually would try to "free (tgt)" again, via
libgomp/target.c:gomp_unmap_tgt:
attribute_hidden void
gomp_unmap_tgt (struct target_mem_desc *tgt)
{
/* Deallocate on target the tgt->tgt_start .. tgt->tgt_end
region. */ if (tgt->tgt_end)
gomp_free_device_memory (tgt->device_descr, tgt->to_free);
free (tgt->array);
free (tgt);
}
Is the "free (tgt)" in libgomp/target.c:gomp_unmap_vars_async wrong,
or something else?
I think I understand the problem now. In gomp_unmap_vars_async(), in the case of
tgt->list_count == 0 (i.e. no map arguments at all) the code should simply free
the tgt
and return, while the code in goacc_async_copyout_unmap_vars() didn't handle
this case
and always scheduled an asynchronous free of the tgt later, causing that
valgrind error
you see.
I am still testing the attached patch, but I think it is the right fix: I
reviewed what I
wrote and it seemed the way I organized things into a
goacc_async_copyout_unmap_vars() routine,
including the hackish refcount++, etc. is simply unneeded. I have deleted those
stuff
and consolidated things back into gomp_unmap_vars_async().
I'll update the whole patches later after complete testing, the attached is the
patch atop
of the prior async patches. (the small program you gave above does pass
valgrind now)
Julian, I didn't try the OG8 refcount changes, it's just too large a set of
changes to
reason about in so short time, maybe later when we are prepared to fix things
completely as
you noted what those patches were capable of.
Chung-Lin
diff -ru trunk-orig/libgomp/oacc-async.c trunk-work/libgomp/oacc-async.c
--- trunk-orig/libgomp/oacc-async.c 2018-12-14 21:06:06.649794724 +0800
+++ trunk-work/libgomp/oacc-async.c 2018-12-14 22:11:29.252251925 +0800
@@ -238,31 +238,6 @@
thr->default_async = async;
}
-static void
-goacc_async_unmap_tgt (void *ptr)
-{
- struct target_mem_desc *tgt = (struct target_mem_desc *) ptr;
-
- if (tgt->refcount > 1)
- tgt->refcount--;
- else
- gomp_unmap_tgt (tgt);
-}
-
-attribute_hidden void
-goacc_async_copyout_unmap_vars (struct target_mem_desc *tgt,
- struct goacc_asyncqueue *aq)
-{
- struct gomp_device_descr *devicep = tgt->device_descr;
-
- /* Increment reference to delay freeing of device memory until callback
- has triggered. */
- tgt->refcount++;
- gomp_unmap_vars_async (tgt, true, aq);
- devicep->openacc.async.queue_callback_func (aq, goacc_async_unmap_tgt,
- (void *) tgt);
-}
-
attribute_hidden void
goacc_async_free (struct gomp_device_descr *devicep,
struct goacc_asyncqueue *aq, void *ptr)
diff -ru trunk-orig/libgomp/oacc-int.h trunk-work/libgomp/oacc-int.h
--- trunk-orig/libgomp/oacc-int.h 2018-12-14 21:06:06.649794724 +0800
+++ trunk-work/libgomp/oacc-int.h 2018-12-14 22:11:43.379947915 +0800
@@ -104,8 +104,6 @@
void goacc_init_asyncqueues (struct gomp_device_descr *);
bool goacc_fini_asyncqueues (struct gomp_device_descr *);
-void goacc_async_copyout_unmap_vars (struct target_mem_desc *,
- struct goacc_asyncqueue *);
void goacc_async_free (struct gomp_device_descr *, struct goacc_asyncqueue *,
void *);
struct goacc_asyncqueue *get_goacc_asyncqueue (int);
diff -ru trunk-orig/libgomp/oacc-mem.c trunk-work/libgomp/oacc-mem.c
--- trunk-orig/libgomp/oacc-mem.c 2018-12-14 21:06:06.649794724 +0800
+++ trunk-work/libgomp/oacc-mem.c 2018-12-14 22:10:08.325998369 +0800
@@ -911,7 +911,7 @@
else
{
goacc_aq aq = get_goacc_asyncqueue (async);
- goacc_async_copyout_unmap_vars (t, aq);
+ gomp_unmap_vars_async (t, true, aq);
}
}
diff -ru trunk-orig/libgomp/oacc-parallel.c trunk-work/libgomp/oacc-parallel.c
--- trunk-orig/libgomp/oacc-parallel.c 2018-12-14 21:06:06.649794724 +0800
+++ trunk-work/libgomp/oacc-parallel.c 2018-12-14 22:09:51.918353575 +0800
@@ -245,7 +245,7 @@
{
acc_dev->openacc.async.exec_func (tgt_fn, mapnum, hostaddrs, devaddrs,
dims, tgt, aq);
- goacc_async_copyout_unmap_vars (tgt, aq);
+ gomp_unmap_vars_async (tgt, true, aq);
}
}
diff -ru trunk-orig/libgomp/target.c trunk-work/libgomp/target.c
--- trunk-orig/libgomp/target.c 2018-12-14 21:06:06.653794622 +0800
+++ trunk-work/libgomp/target.c 2018-12-14 20:42:03.629154346 +0800
@@ -1072,6 +1072,17 @@
return is_tgt_unmapped;
}
+static void
+gomp_unref_tgt (void *ptr)
+{
+ struct target_mem_desc *tgt = (struct target_mem_desc *) ptr;
+
+ if (tgt->refcount > 1)
+ tgt->refcount--;
+ else
+ gomp_unmap_tgt (tgt);
+}
+
/* Unmap variables described by TGT. If DO_COPYFROM is true, copy relevant
variables back from device to host: if it is false, it is assumed that this
has been done already. */
@@ -1130,10 +1141,11 @@
gomp_remove_var (devicep, k);
}
- if (tgt->refcount > 1)
- tgt->refcount--;
+ if (aq)
+ devicep->openacc.async.queue_callback_func (aq, gomp_unref_tgt,
+ (void *) tgt);
else
- gomp_unmap_tgt (tgt);
+ gomp_unref_tgt ((void *) tgt);
gomp_mutex_unlock (&devicep->lock);
}
