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Groups > linux.kernel > #1435303 > unrolled thread
| Started by | Gustavo Padovan <gustavo@padovan.org> |
|---|---|
| First post | 2016-07-01 15:10 +0200 |
| Last post | 2016-07-01 15:30 +0200 |
| Articles | 5 — 2 participants |
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[PATCH v2 0/4] dma-buf/sync_file: rework fences on struct sync_file Gustavo Padovan <gustavo@padovan.org> - 2016-07-01 15:10 +0200
[PATCH v2 1/4] dma-buf/fence-array: add fence_is_array() Gustavo Padovan <gustavo@padovan.org> - 2016-07-01 15:10 +0200
[PATCH v2 4/4] Documentation: add doc for sync_file_get_fence() Gustavo Padovan <gustavo@padovan.org> - 2016-07-01 15:10 +0200
[PATCH v2 2/4] dma-buf/sync_file: rework fence storage in struct file Gustavo Padovan <gustavo@padovan.org> - 2016-07-01 15:10 +0200
Re: [PATCH v2 2/4] dma-buf/sync_file: rework fence storage in struct file Chris Wilson <chris@chris-wilson.co.uk> - 2016-07-01 15:30 +0200
| From | Gustavo Padovan <gustavo@padovan.org> |
|---|---|
| Date | 2016-07-01 15:10 +0200 |
| Subject | [PATCH v2 0/4] dma-buf/sync_file: rework fences on struct sync_file |
| Message-ID | <rQ6mJ-72X-5@gated-at.bofh.it> |
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Hi all, This is an attempt to improve fence support on Sync File. The basic idea is to have only sync_file->fence and store all fences there, either as normal fences or fence_arrays. That way we can remove some potential duplication when using fence_array with sync_file: the duplication of the array of fences and the duplication of fence_add_callback() for all fences. Now when creating a new sync_file during the merge process sync_file_set_fence() will set sync_file->fence based on the number of fences for that sync_file. If there is more than one fence a fence_array is created. One important advantage approach is that we only add one fence callback now, no matter how many fences there are in a sync_file - the individual callbacks are added by fence_array. This patchset also adds sync_file_get_fence() to retrieve fence from a sync_file file descriptor. Please review! Thanks! Gustavo --- Changes since PATCH v1 Comments from Chris Wilson) - use sizeof(*fence) to reallocate array - fix typo in comments - protect num_fences sum against overflows - use array->base instead of casting the to struct fence - remove ternary if from ops comparison in fence_is_array() - add EXPORT_SYMBOL(fence_array_ops) Changes since RFC v2 (Comments from Chris Wilson and Christian König): - struct sync_file lost status member in favor of fence_is_signaled() - drop use of fence_array_teardown() - use sizeof(*fence) to allocate only an array on fence pointers Changes since RFC v1 (Comments from Chris Wilson and Christian König): - Not using fence_ops anymore. - fence_is_array() was created to differentiate fence from fence_array - fence_array_teardown() is now exported and used under fence_is_array() - struct sync_file lost num_fences member Gustavo Padovan (4): dma-buf/fence-array: add fence_is_array() dma-buf/sync_file: rework fence storage in struct file dma-buf/sync_file: add sync_file_get_fence() Documentation: add doc for sync_file_get_fence() Documentation/sync_file.txt | 15 +++ drivers/dma-buf/fence-array.c | 1 + drivers/dma-buf/sync_file.c | 190 ++++++++++++++++++++++++----------- drivers/staging/android/sync_debug.c | 13 ++- include/linux/fence-array.h | 10 ++ include/linux/sync_file.h | 18 ++-- 6 files changed, 172 insertions(+), 75 deletions(-) -- 2.5.5
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| From | Gustavo Padovan <gustavo@padovan.org> |
|---|---|
| Date | 2016-07-01 15:10 +0200 |
| Subject | [PATCH v2 1/4] dma-buf/fence-array: add fence_is_array() |
| Message-ID | <rQ6mJ-72X-13@gated-at.bofh.it> |
| In reply to | #1435303 |
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Add helper to check if fence is array.
v2: Comments from Chris Wilson
- remove ternary if from ops comparison
- add EXPORT_SYMBOL(fence_array_ops)
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/dma-buf/fence-array.c | 1 +
include/linux/fence-array.h | 10 ++++++++++
2 files changed, 11 insertions(+)
diff --git a/drivers/dma-buf/fence-array.c b/drivers/dma-buf/fence-array.c
index a8731c8..ee50022 100644
--- a/drivers/dma-buf/fence-array.c
+++ b/drivers/dma-buf/fence-array.c
@@ -99,6 +99,7 @@ const struct fence_ops fence_array_ops = {
.wait = fence_default_wait,
.release = fence_array_release,
};
+EXPORT_SYMBOL(fence_array_ops);
/**
* fence_array_create - Create a custom fence array
diff --git a/include/linux/fence-array.h b/include/linux/fence-array.h
index 86baaa4..a44794e 100644
--- a/include/linux/fence-array.h
+++ b/include/linux/fence-array.h
@@ -52,6 +52,16 @@ struct fence_array {
extern const struct fence_ops fence_array_ops;
/**
+ * fence_is_array - check if a fence is from the array subsclass
+ *
+ * Return true if it is a fence_array and false otherwise.
+ */
+static inline bool fence_is_array(struct fence *fence)
+{
+ return fence->ops == &fence_array_ops;
+}
+
+/**
* to_fence_array - cast a fence to a fence_array
* @fence: fence to cast to a fence_array
*
--
2.5.5
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| From | Gustavo Padovan <gustavo@padovan.org> |
|---|---|
| Date | 2016-07-01 15:10 +0200 |
| Subject | [PATCH v2 4/4] Documentation: add doc for sync_file_get_fence() |
| Message-ID | <rQ6mK-72X-31@gated-at.bofh.it> |
| In reply to | #1435303 |
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Document the new function added to sync_file.c v2: Adapt to fence_array Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> --- Documentation/sync_file.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/sync_file.txt b/Documentation/sync_file.txt index e8e2eba..ae2dbad1 100644 --- a/Documentation/sync_file.txt +++ b/Documentation/sync_file.txt @@ -64,6 +64,21 @@ The sync_file fd now can be sent to userspace. If the creation process fail, or the sync_file needs to be released by any other reason fput(sync_file->file) should be used. +Receiving Sync Files from Userspace +----------------------------------- + +When userspace needs to send an in-fence to the driver it pass file descriptor +of the Sync File to the kernel. The kernel then can retrieve the fences +from it. + +Interface: + struct fence *sync_file_get_fence(int fd); + + +The function return a struct fence pointer referencing the fence(s) in the Sync +File. + + References: [1] struct sync_file in include/linux/sync_file.h [2] All interfaces mentioned above defined in include/linux/sync_file.h -- 2.5.5
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| From | Gustavo Padovan <gustavo@padovan.org> |
|---|---|
| Date | 2016-07-01 15:10 +0200 |
| Subject | [PATCH v2 2/4] dma-buf/sync_file: rework fence storage in struct file |
| Message-ID | <rQ6mK-72X-27@gated-at.bofh.it> |
| In reply to | #1435303 |
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Create sync_file->fence to abstract the type of fence we are using for
each sync_file. If only one fence is present we use a normal struct fence
but if there is more fences to be added to the sync_file a fence_array
is created.
This change cleans up sync_file a bit. We don't need to have sync_file_cb
array anymore. Instead, as we always have one fence, only one fence
callback is registered per sync_file.
v4: Comments from Chris Wilson
- use sizeof(*fence) to reallocate array
- fix typo in comments
- protect num_fences sum against overflows
- use array->base instead of casting the to struct fence
v3: Comments from Chris Wilson and Christian König
- struct sync_file lost status member in favor of fence_is_signaled()
- drop use of fence_array_teardown()
- use sizeof(*fence) to allocate only an array on fence pointers
v2: Comments from Chris Wilson and Christian König
- Not using fence_ops anymore
- fence_is_array() was created to differentiate fence from fence_array
- fence_array_teardown() is now exported and used under fence_is_array()
- struct sync_file lost num_fences member
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/dma-buf/sync_file.c | 166 ++++++++++++++++++++++-------------
drivers/staging/android/sync_debug.c | 13 ++-
include/linux/sync_file.h | 17 ++--
3 files changed, 121 insertions(+), 75 deletions(-)
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index 9aaa608..12dbf17 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -28,11 +28,11 @@
static const struct file_operations sync_file_fops;
-static struct sync_file *sync_file_alloc(int size)
+static struct sync_file *sync_file_alloc(void)
{
struct sync_file *sync_file;
- sync_file = kzalloc(size, GFP_KERNEL);
+ sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
if (!sync_file)
return NULL;
@@ -45,6 +45,8 @@ static struct sync_file *sync_file_alloc(int size)
init_waitqueue_head(&sync_file->wq);
+ INIT_LIST_HEAD(&sync_file->cb.node);
+
return sync_file;
err:
@@ -54,14 +56,11 @@ err:
static void fence_check_cb_func(struct fence *f, struct fence_cb *cb)
{
- struct sync_file_cb *check;
struct sync_file *sync_file;
- check = container_of(cb, struct sync_file_cb, cb);
- sync_file = check->sync_file;
+ sync_file = container_of(cb, struct sync_file, cb);
- if (atomic_dec_and_test(&sync_file->status))
- wake_up_all(&sync_file->wq);
+ wake_up_all(&sync_file->wq);
}
/**
@@ -76,22 +75,18 @@ struct sync_file *sync_file_create(struct fence *fence)
{
struct sync_file *sync_file;
- sync_file = sync_file_alloc(offsetof(struct sync_file, cbs[1]));
+ sync_file = sync_file_alloc();
if (!sync_file)
return NULL;
- sync_file->num_fences = 1;
- atomic_set(&sync_file->status, 1);
+ sync_file->fence = fence;
+
snprintf(sync_file->name, sizeof(sync_file->name), "%s-%s%llu-%d",
fence->ops->get_driver_name(fence),
fence->ops->get_timeline_name(fence), fence->context,
fence->seqno);
- sync_file->cbs[0].fence = fence;
- sync_file->cbs[0].sync_file = sync_file;
- if (fence_add_callback(fence, &sync_file->cbs[0].cb,
- fence_check_cb_func))
- atomic_dec(&sync_file->status);
+ fence_add_callback(fence, &sync_file->cb, fence_check_cb_func);
return sync_file;
}
@@ -121,14 +116,48 @@ err:
return NULL;
}
-static void sync_file_add_pt(struct sync_file *sync_file, int *i,
- struct fence *fence)
+static int sync_file_set_fence(struct sync_file *sync_file,
+ struct fence **fences, int num_fences)
+{
+ struct fence_array *array;
+
+ /*
+ * The reference for the fences in the new sync_file and held
+ * in add_fence() during the merge procedure, so for num_fences == 1
+ * we already own a new reference to the fence. For num_fence > 1
+ * we own the reference of the fence_array creation.
+ */
+ if (num_fences == 1) {
+ sync_file->fence = fences[0];
+ } else {
+ array = fence_array_create(num_fences, fences,
+ fence_context_alloc(1), 1, false);
+ if (!array)
+ return -ENOMEM;
+
+ sync_file->fence = &array->base;
+ }
+
+ return 0;
+}
+
+static struct fence **get_fences(struct sync_file *sync_file, int *num_fences)
+{
+ if (fence_is_array(sync_file->fence)) {
+ struct fence_array *array = to_fence_array(sync_file->fence);
+ *num_fences = array->num_fences;
+ return array->fences;
+ } else {
+ *num_fences = 1;
+ return &sync_file->fence;
+ }
+}
+
+static void add_fence(struct fence **fences, int *i, struct fence *fence)
{
- sync_file->cbs[*i].fence = fence;
- sync_file->cbs[*i].sync_file = sync_file;
+ fences[*i] = fence;
- if (!fence_add_callback(fence, &sync_file->cbs[*i].cb,
- fence_check_cb_func)) {
+ if (!fence_is_signaled(fence)) {
fence_get(fence);
(*i)++;
}
@@ -147,16 +176,24 @@ static void sync_file_add_pt(struct sync_file *sync_file, int *i,
static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
struct sync_file *b)
{
- int num_fences = a->num_fences + b->num_fences;
struct sync_file *sync_file;
- int i, i_a, i_b;
- unsigned long size = offsetof(struct sync_file, cbs[num_fences]);
+ struct fence **fences, **a_fences, **b_fences;
+ int i, i_a, i_b, num_fences, a_num_fences, b_num_fences;
- sync_file = sync_file_alloc(size);
+ sync_file = sync_file_alloc();
if (!sync_file)
return NULL;
- atomic_set(&sync_file->status, num_fences);
+ a_fences = get_fences(a, &a_num_fences);
+ b_fences = get_fences(b, &b_num_fences);
+ if (a_num_fences > INT_MAX - b_num_fences)
+ return NULL;
+
+ num_fences = a_num_fences + b_num_fences;
+
+ fences = kcalloc(num_fences, sizeof(*fences), GFP_KERNEL);
+ if (!fences)
+ goto err;
/*
* Assume sync_file a and b are both ordered and have no
@@ -165,55 +202,66 @@ static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
* If a sync_file can only be created with sync_file_merge
* and sync_file_create, this is a reasonable assumption.
*/
- for (i = i_a = i_b = 0; i_a < a->num_fences && i_b < b->num_fences; ) {
- struct fence *pt_a = a->cbs[i_a].fence;
- struct fence *pt_b = b->cbs[i_b].fence;
+ for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {
+ struct fence *pt_a = a_fences[i_a];
+ struct fence *pt_b = b_fences[i_b];
if (pt_a->context < pt_b->context) {
- sync_file_add_pt(sync_file, &i, pt_a);
+ add_fence(fences, &i, pt_a);
i_a++;
} else if (pt_a->context > pt_b->context) {
- sync_file_add_pt(sync_file, &i, pt_b);
+ add_fence(fences, &i, pt_b);
i_b++;
} else {
if (pt_a->seqno - pt_b->seqno <= INT_MAX)
- sync_file_add_pt(sync_file, &i, pt_a);
+ add_fence(fences, &i, pt_a);
else
- sync_file_add_pt(sync_file, &i, pt_b);
+ add_fence(fences, &i, pt_b);
i_a++;
i_b++;
}
}
- for (; i_a < a->num_fences; i_a++)
- sync_file_add_pt(sync_file, &i, a->cbs[i_a].fence);
+ for (; i_a < a_num_fences; i_a++)
+ add_fence(fences, &i, a_fences[i_a]);
+
+ for (; i_b < b_num_fences; i_b++)
+ add_fence(fences, &i, b_fences[i_b]);
- for (; i_b < b->num_fences; i_b++)
- sync_file_add_pt(sync_file, &i, b->cbs[i_b].fence);
+ if (num_fences > i) {
+ fences = krealloc(fences, i * sizeof(*fences),
+ GFP_KERNEL);
+ if (!fences)
+ goto err;
+ }
+
+ if (sync_file_set_fence(sync_file, fences, i) < 0) {
+ kfree(fences);
+ goto err;
+ }
- if (num_fences > i)
- atomic_sub(num_fences - i, &sync_file->status);
- sync_file->num_fences = i;
+ fence_add_callback(sync_file->fence, &sync_file->cb,
+ fence_check_cb_func);
strlcpy(sync_file->name, name, sizeof(sync_file->name));
return sync_file;
+
+err:
+ fput(sync_file->file);
+ return NULL;
+
}
static void sync_file_free(struct kref *kref)
{
struct sync_file *sync_file = container_of(kref, struct sync_file,
kref);
- int i;
-
- for (i = 0; i < sync_file->num_fences; ++i) {
- fence_remove_callback(sync_file->cbs[i].fence,
- &sync_file->cbs[i].cb);
- fence_put(sync_file->cbs[i].fence);
- }
+ fence_remove_callback(sync_file->fence, &sync_file->cb);
+ fence_put(sync_file->fence);
kfree(sync_file);
}
@@ -232,9 +280,9 @@ static unsigned int sync_file_poll(struct file *file, poll_table *wait)
poll_wait(file, &sync_file->wq, wait);
- status = atomic_read(&sync_file->status);
+ status = fence_is_signaled(sync_file->fence);
- if (!status)
+ if (status)
return POLLIN;
if (status < 0)
return POLLERR;
@@ -315,8 +363,9 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
{
struct sync_file_info info;
struct sync_fence_info *fence_info = NULL;
+ struct fence **fences;
__u32 size;
- int ret, i;
+ int num_fences, ret, i;
if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
return -EFAULT;
@@ -324,6 +373,8 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
if (info.flags || info.pad)
return -EINVAL;
+ fences = get_fences(sync_file, &num_fences);
+
/*
* Passing num_fences = 0 means that userspace doesn't want to
* retrieve any sync_fence_info. If num_fences = 0 we skip filling
@@ -333,16 +384,16 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
if (!info.num_fences)
goto no_fences;
- if (info.num_fences < sync_file->num_fences)
+ if (info.num_fences < num_fences)
return -EINVAL;
- size = sync_file->num_fences * sizeof(*fence_info);
+ size = num_fences * sizeof(*fence_info);
fence_info = kzalloc(size, GFP_KERNEL);
if (!fence_info)
return -ENOMEM;
- for (i = 0; i < sync_file->num_fences; ++i)
- sync_fill_fence_info(sync_file->cbs[i].fence, &fence_info[i]);
+ for (i = 0; i < num_fences; i++)
+ sync_fill_fence_info(fences[i], &fence_info[i]);
if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
size)) {
@@ -352,11 +403,8 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
no_fences:
strlcpy(info.name, sync_file->name, sizeof(info.name));
- info.status = atomic_read(&sync_file->status);
- if (info.status >= 0)
- info.status = !info.status;
-
- info.num_fences = sync_file->num_fences;
+ info.status = fence_is_signaled(sync_file->fence);
+ info.num_fences = num_fences;
if (copy_to_user((void __user *)arg, &info, sizeof(info)))
ret = -EFAULT;
diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c
index 5f57499..0638a06 100644
--- a/drivers/staging/android/sync_debug.c
+++ b/drivers/staging/android/sync_debug.c
@@ -159,10 +159,15 @@ static void sync_print_sync_file(struct seq_file *s,
int i;
seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name,
- sync_status_str(atomic_read(&sync_file->status)));
-
- for (i = 0; i < sync_file->num_fences; ++i)
- sync_print_fence(s, sync_file->cbs[i].fence, true);
+ sync_status_str(!fence_is_signaled(sync_file->fence)));
+
+ if (fence_is_array(sync_file->fence)) {
+ struct fence_array *array = to_fence_array(sync_file->fence);
+ for (i = 0; i < array->num_fences; ++i)
+ sync_print_fence(s, array->fences[i], true);
+ } else {
+ sync_print_fence(s, sync_file->fence, true);
+ }
}
static int sync_debugfs_show(struct seq_file *s, void *unused)
diff --git a/include/linux/sync_file.h b/include/linux/sync_file.h
index c6ffe8b..2efc5ec 100644
--- a/include/linux/sync_file.h
+++ b/include/linux/sync_file.h
@@ -19,12 +19,7 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/fence.h>
-
-struct sync_file_cb {
- struct fence_cb cb;
- struct fence *fence;
- struct sync_file *sync_file;
-};
+#include <linux/fence-array.h>
/**
* struct sync_file - sync file to export to the userspace
@@ -32,10 +27,9 @@ struct sync_file_cb {
* @kref: reference count on fence.
* @name: name of sync_file. Useful for debugging
* @sync_file_list: membership in global file list
- * @num_fences: number of sync_pts in the fence
* @wq: wait queue for fence signaling
- * @status: 0: signaled, >0:active, <0: error
- * @cbs: sync_pts callback information
+ * @fence: fence with the fences in the sync_file
+ * @cb: fence callback information
*/
struct sync_file {
struct file *file;
@@ -44,12 +38,11 @@ struct sync_file {
#ifdef CONFIG_DEBUG_FS
struct list_head sync_file_list;
#endif
- int num_fences;
wait_queue_head_t wq;
- atomic_t status;
- struct sync_file_cb cbs[];
+ struct fence *fence;
+ struct fence_cb cb;
};
struct sync_file *sync_file_create(struct fence *fence);
--
2.5.5
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| From | Chris Wilson <chris@chris-wilson.co.uk> |
|---|---|
| Date | 2016-07-01 15:30 +0200 |
| Subject | Re: [PATCH v2 2/4] dma-buf/sync_file: rework fence storage in struct file |
| Message-ID | <rQ6G5-79F-21@gated-at.bofh.it> |
| In reply to | #1435312 |
On Fri, Jul 01, 2016 at 10:05:05AM -0300, Gustavo Padovan wrote:
> @@ -333,16 +384,16 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
> if (!info.num_fences)
> goto no_fences;
>
> - if (info.num_fences < sync_file->num_fences)
> + if (info.num_fences < num_fences)
> return -EINVAL;
>
> - size = sync_file->num_fences * sizeof(*fence_info);
> + size = num_fences * sizeof(*fence_info);
> fence_info = kzalloc(size, GFP_KERNEL);
Does size get used elsewhere? Otherwise it would be safer to reduce this
to kcalloc(num_fences, sizeof(*fence_info), GFP_KERNEL)
> if (!fence_info)
> return -ENOMEM;
>
> diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c
> index 5f57499..0638a06 100644
> --- a/drivers/staging/android/sync_debug.c
> +++ b/drivers/staging/android/sync_debug.c
> @@ -159,10 +159,15 @@ static void sync_print_sync_file(struct seq_file *s,
> int i;
>
> seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name,
> - sync_status_str(atomic_read(&sync_file->status)));
> -
> - for (i = 0; i < sync_file->num_fences; ++i)
> - sync_print_fence(s, sync_file->cbs[i].fence, true);
> + sync_status_str(!fence_is_signaled(sync_file->fence)));
> +
> + if (fence_is_array(sync_file->fence)) {
> + struct fence_array *array = to_fence_array(sync_file->fence);
checkpatch will complain about the missing line between decl and code
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
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