From: John Stultz <john.stultz@linaro.org>
To: lkml <linux-kernel@vger.kernel.org>
Cc: Erik Gilling <konkers@android.com>,
Maarten Lankhorst <maarten.lankhorst@canonical.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
Rob Clark <robclark@gmail.com>,
Sumit Semwal <sumit.semwal@linaro.org>,
Greg KH <gregkh@linuxfoundation.org>,
dri-devel@lists.freedesktop.org,
Android Kernel Team <kernel-team@android.com>,
John Stultz <john.stultz@linaro.org>
Subject: [PATCH 15/30] staging: sync: Add reference counting to timelines
Date: Thu, 28 Feb 2013 16:43:11 -0800 [thread overview]
Message-ID: <1362098606-26469-16-git-send-email-john.stultz@linaro.org> (raw)
In-Reply-To: <1362098606-26469-1-git-send-email-john.stultz@linaro.org>
From: Erik Gilling <konkers@android.com>
If a timeline is destroyed while fences still hold pts on it, the reworked
fence release handler can cause the timeline to be freed before all it's points
are freed.
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Erik Gilling <konkers@android.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Clark <robclark@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: dri-devel@lists.freedesktop.org
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Erik Gilling <konkers@android.com>
[jstultz: Squished in compiler warning fix]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/staging/android/sync.c | 29 +++++++++++++----------------
drivers/staging/android/sync.h | 2 ++
2 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
index 7d4e9aa..61c27bd 100644
--- a/drivers/staging/android/sync.c
+++ b/drivers/staging/android/sync.c
@@ -51,6 +51,7 @@ struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,
if (obj == NULL)
return NULL;
+ kref_init(&obj->kref);
obj->ops = ops;
strlcpy(obj->name, name, sizeof(obj->name));
@@ -68,8 +69,10 @@ struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,
}
EXPORT_SYMBOL(sync_timeline_create);
-static void sync_timeline_free(struct sync_timeline *obj)
+static void sync_timeline_free(struct kref *kref)
{
+ struct sync_timeline *obj =
+ container_of(kref, struct sync_timeline, kref);
unsigned long flags;
if (obj->ops->release_obj)
@@ -84,17 +87,14 @@ static void sync_timeline_free(struct sync_timeline *obj)
void sync_timeline_destroy(struct sync_timeline *obj)
{
- unsigned long flags;
- bool needs_freeing;
-
- spin_lock_irqsave(&obj->child_list_lock, flags);
obj->destroyed = true;
- needs_freeing = list_empty(&obj->child_list_head);
- spin_unlock_irqrestore(&obj->child_list_lock, flags);
- if (needs_freeing)
- sync_timeline_free(obj);
- else
+ /*
+ * If this is not the last reference, signal any children
+ * that their parent is going away.
+ */
+
+ if (!kref_put(&obj->kref, sync_timeline_free))
sync_timeline_signal(obj);
}
EXPORT_SYMBOL(sync_timeline_destroy);
@@ -114,7 +114,6 @@ static void sync_timeline_remove_pt(struct sync_pt *pt)
{
struct sync_timeline *obj = pt->parent;
unsigned long flags;
- bool needs_freeing = false;
spin_lock_irqsave(&obj->active_list_lock, flags);
if (!list_empty(&pt->active_list))
@@ -124,13 +123,8 @@ static void sync_timeline_remove_pt(struct sync_pt *pt)
spin_lock_irqsave(&obj->child_list_lock, flags);
if (!list_empty(&pt->child_list)) {
list_del_init(&pt->child_list);
- needs_freeing = obj->destroyed &&
- list_empty(&obj->child_list_head);
}
spin_unlock_irqrestore(&obj->child_list_lock, flags);
-
- if (needs_freeing)
- sync_timeline_free(obj);
}
void sync_timeline_signal(struct sync_timeline *obj)
@@ -177,6 +171,7 @@ struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size)
return NULL;
INIT_LIST_HEAD(&pt->active_list);
+ kref_get(&parent->kref);
sync_timeline_add_pt(parent, pt);
return pt;
@@ -190,6 +185,8 @@ void sync_pt_free(struct sync_pt *pt)
sync_timeline_remove_pt(pt);
+ kref_put(&pt->parent->kref, sync_timeline_free);
+
kfree(pt);
}
EXPORT_SYMBOL(sync_pt_free);
diff --git a/drivers/staging/android/sync.h b/drivers/staging/android/sync.h
index 00c9bae..15863a6 100644
--- a/drivers/staging/android/sync.h
+++ b/drivers/staging/android/sync.h
@@ -80,6 +80,7 @@ struct sync_timeline_ops {
/**
* struct sync_timeline - sync object
+ * @kref: reference count on fence.
* @ops: ops that define the implementaiton of the sync_timeline
* @name: name of the sync_timeline. Useful for debugging
* @destoryed: set when sync_timeline is destroyed
@@ -90,6 +91,7 @@ struct sync_timeline_ops {
* @sync_timeline_list: membership in global sync_timeline_list
*/
struct sync_timeline {
+ struct kref kref;
const struct sync_timeline_ops *ops;
char name[32];
--
1.7.10.4
next prev parent reply other threads:[~2013-03-01 0:48 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-01 0:42 [RFC][PATCH 00/30] staging: Android sync driver John Stultz
2013-03-01 0:42 ` [PATCH 01/30] staging: sync: Add synchronization framework John Stultz
2013-03-01 0:42 ` [PATCH 02/30] staging: sw_sync: Add cpu based sync driver John Stultz
2013-03-01 0:42 ` [PATCH 03/30] staging: sync: Add timestamps to sync_pts John Stultz
2013-03-01 0:43 ` [PATCH 04/30] staging: sync: Add debugfs support John Stultz
2013-03-01 0:43 ` [PATCH 05/30] staging: sw_sync: Add debug support John Stultz
2013-03-01 0:43 ` [PATCH 06/30] staging: sync: Add ioctl to get fence data John Stultz
2013-03-01 0:43 ` [PATCH 07/30] staging: sw_sync: Add fill_driver_data support John Stultz
2013-03-01 0:43 ` [PATCH 08/30] staging: sync: Add poll support John Stultz
2013-03-01 0:43 ` [PATCH 09/30] staging: sync: Allow async waits to be canceled John Stultz
2013-03-01 0:43 ` [PATCH 10/30] staging: sync: Export sync API symbols John Stultz
2013-03-01 2:00 ` Greg KH
2013-03-01 3:59 ` John Stultz
2013-03-01 8:21 ` Erik Gilling
2013-03-01 13:55 ` Greg KH
2013-03-01 16:30 ` Erik Gilling
2013-03-01 22:47 ` Erik Gilling
2013-03-01 0:43 ` [PATCH 11/30] staging: sw_sync: Export sw_sync API John Stultz
2013-03-01 0:43 ` [PATCH 12/30] staging: sync: Reorder sync_fence_release John Stultz
2013-03-01 0:43 ` [PATCH 13/30] staging: sync: Optimize fence merges John Stultz
2013-03-01 0:43 ` [PATCH 14/30] staging: sync: Add internal refcounting to fences John Stultz
2013-03-01 0:43 ` John Stultz [this message]
2013-03-01 0:43 ` [PATCH 16/30] staging: sync: Fix error paths John Stultz
2013-03-01 0:43 ` [PATCH 17/30] staging: sw_sync: " John Stultz
2013-03-01 0:43 ` [PATCH 18/30] staging: sync: Change wait timeout to mirror poll semantics John Stultz
2013-03-01 0:43 ` [PATCH 19/30] staging: sync: Dump sync state to console on timeout John Stultz
2013-03-01 0:43 ` [PATCH 20/30] staging: sync: Improve timeout dump messages John Stultz
2013-03-01 0:43 ` [PATCH 21/30] staging: sync: Dump sync state on fence errors John Stultz
2013-03-01 0:43 ` [PATCH 22/30] staging: sync: Protect unlocked access to fence status John Stultz
2013-03-01 0:43 ` [PATCH 23/30] staging: sync: Update new fence status with sync_fence_signal_pt John Stultz
2013-03-01 0:43 ` [PATCH 24/30] staging: sync: Use proper barriers when waiting indefinitely John Stultz
2013-03-01 0:43 ` [PATCH 25/30] staging: sync: Refactor sync debug printing John Stultz
2013-03-01 0:43 ` [PATCH 26/30] staging: sw_sync: Convert to use new value_str debug ops John Stultz
2013-03-01 0:43 ` [PATCH 27/30] staging: sync: Add tracepoint support John Stultz
2013-03-01 0:43 ` [PATCH 28/30] staging: sync: Fix race condition between merge and signal John Stultz
2013-03-01 0:43 ` [PATCH 29/30] staging: sync: Don't log wait timeouts when timeout = 0 John Stultz
2013-03-01 0:43 ` [PATCH 30/30] staging: sync: Fix timeout = 0 wait behavior John Stultz
2013-03-01 1:59 ` [RFC][PATCH 00/30] staging: Android sync driver Greg KH
2013-03-01 16:20 ` Erik Gilling
2013-03-03 18:42 ` Daniel Vetter
2013-03-03 18:52 ` animelovin
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