[SRU][Bionic][Cosmic][PATCH 1/1] drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set

Joseph Salisbury joseph.salisbury at canonical.com
Wed Oct 31 18:28:09 UTC 2018


From: Jason Ekstrand <jason at jlekstrand.net>

BugLink: https://bugs.launchpad.net/bugs/1798165

We attempt to get fences earlier in the hopes that everything will
already have fences and no callbacks will be needed.  If we do succeed
in getting a fence, getting one a second time will result in a duplicate
ref with no unref.  This is causing memory leaks in Vulkan applications
that create a lot of fences; playing for a few hours can, apparently,
bring down the system.

Cc: stable at vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107899
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
Signed-off-by: Sean Paul <seanpaul at chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180926071703.15257-1-jason.ekstrand@intel.com
(cherry picked from commit 337fe9f5c1e7de1f391c6a692531379d2aa2ee11)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 drivers/gpu/drm/drm_syncobj.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index cb4d09c..ba7cdec 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -96,6 +96,8 @@ static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj,
 {
 	int ret;
 
+	WARN_ON(*fence);
+
 	*fence = drm_syncobj_fence_get(syncobj);
 	if (*fence)
 		return 1;
@@ -704,6 +706,9 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
 
 	if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
 		for (i = 0; i < count; ++i) {
+			if (entries[i].fence)
+				continue;
+
 			drm_syncobj_fence_get_or_add_callback(syncobjs[i],
 							      &entries[i].fence,
 							      &entries[i].syncobj_cb,
-- 
2.7.4





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