Useful for getting a quick looks at the state of synchronization. This is especially nice when a graphics pipeline locks up and you want to see what is no longer making progress.
Signed-off-by: Erik Gilling konkers@android.com --- drivers/base/sync.c | 176 +++++++++++++++++++++++++++++++++++++++++++++++++- include/linux/sync.h | 20 +++++- 2 files changed, 191 insertions(+), 5 deletions(-)
diff --git a/drivers/base/sync.c b/drivers/base/sync.c index ea0b664..49fcfc4 100644 --- a/drivers/base/sync.c +++ b/drivers/base/sync.c @@ -14,10 +14,12 @@ * */
+#include <linux/debugfs.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/kernel.h> #include <linux/sched.h> +#include <linux/seq_file.h> #include <linux/slab.h> #include <linux/sync.h> #include <linux/uaccess.h> @@ -27,10 +29,17 @@ static void sync_fence_signal_pt(struct sync_pt *pt); static int _sync_pt_has_signaled(struct sync_pt *pt);
+static LIST_HEAD(sync_timeline_list_head); +static DEFINE_SPINLOCK(sync_timeline_list_lock); + +static LIST_HEAD(sync_fence_list_head); +static DEFINE_SPINLOCK(sync_fence_list_lock); + struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops, int size, const char *name) { struct sync_timeline *obj; + unsigned long flags;
if (size < sizeof(struct sync_timeline)) return NULL; @@ -48,9 +57,27 @@ struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops, INIT_LIST_HEAD(&obj->active_list_head); spin_lock_init(&obj->active_list_lock);
+ spin_lock_irqsave(&sync_timeline_list_lock, flags); + list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head); + spin_unlock_irqrestore(&sync_timeline_list_lock, flags); + return obj; }
+static void sync_timeline_free(struct sync_timeline *obj) +{ + unsigned long flags; + + if (obj->ops->release_obj) + obj->ops->release_obj(obj); + + spin_lock_irqsave(&sync_timeline_list_lock, flags); + list_del(&obj->sync_timeline_list); + spin_unlock_irqrestore(&sync_timeline_list_lock, flags); + + kfree(obj); +} + void sync_timeline_destroy(struct sync_timeline *obj) { unsigned long flags; @@ -62,7 +89,7 @@ void sync_timeline_destroy(struct sync_timeline *obj) spin_unlock_irqrestore(&obj->child_list_lock, flags);
if (needs_freeing) - kfree(obj); + sync_timeline_free(obj); else sync_timeline_signal(obj); } @@ -95,7 +122,7 @@ static void sync_timeline_remove_pt(struct sync_pt *pt) spin_unlock_irqrestore(&obj->child_list_lock, flags);
if (needs_freeing) - kfree(obj); + sync_timeline_free(obj); }
void sync_timeline_signal(struct sync_timeline *obj) @@ -206,6 +233,7 @@ static const struct file_operations sync_fence_fops = { static struct sync_fence *sync_fence_alloc(const char *name) { struct sync_fence *fence; + unsigned long flags;
fence = kzalloc(sizeof(struct sync_fence), GFP_KERNEL); if (fence == NULL) @@ -223,6 +251,11 @@ static struct sync_fence *sync_fence_alloc(const char *name) spin_lock_init(&fence->waiter_list_lock);
init_waitqueue_head(&fence->wq); + + spin_lock_irqsave(&sync_fence_list_lock, flags); + list_add_tail(&fence->sync_fence_list, &sync_fence_list_head); + spin_unlock_irqrestore(&sync_fence_list_lock, flags); + return fence;
err: @@ -451,8 +484,14 @@ int sync_fence_wait(struct sync_fence *fence, long timeout) static int sync_fence_release(struct inode *inode, struct file *file) { struct sync_fence *fence = file->private_data; + unsigned long flags;
sync_fence_free_pts(fence); + + spin_lock_irqsave(&sync_fence_list_lock, flags); + list_del(&fence->sync_fence_list); + spin_unlock_irqrestore(&sync_fence_list_lock, flags); + kfree(fence);
return 0; @@ -523,8 +562,141 @@ static long sync_fence_ioctl(struct file *file, unsigned int cmd,
case SYNC_IOC_MERGE: return sync_fence_ioctl_merge(fence, arg); + default: return -ENOTTY; } }
+#ifdef CONFIG_DEBUG_FS +static const char *sync_status_str(int status) +{ + if (status > 0) + return "signaled"; + else if (status == 0) + return "active"; + else + return "error"; +} + +static void sync_print_pt(struct seq_file *s, struct sync_pt *pt, bool fence) +{ + int status = pt->status; + seq_printf(s, " %s%spt %s", + fence ? pt->parent->name : "", + fence ? "_" : "", + sync_status_str(status)); + if (pt->status) { + struct timeval tv = ktime_to_timeval(pt->timestamp); + seq_printf(s, "@%ld.%06ld", tv.tv_sec, tv.tv_usec); + } + + if (pt->parent->ops->print_pt) { + seq_printf(s, ": "); + pt->parent->ops->print_pt(s, pt); + } + + seq_printf(s, "\n"); +} + +static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj) +{ + struct list_head *pos; + unsigned long flags; + + seq_printf(s, "%s %s", obj->name, obj->ops->driver_name); + + if (obj->ops->print_obj) { + seq_printf(s, ": "); + obj->ops->print_obj(s, obj); + } + + seq_printf(s, "\n"); + + spin_lock_irqsave(&obj->child_list_lock, flags); + list_for_each(pos, &obj->child_list_head) { + struct sync_pt *pt = + container_of(pos, struct sync_pt, child_list); + sync_print_pt(s, pt, false); + } + spin_unlock_irqrestore(&obj->child_list_lock, flags); +} + +static void sync_print_fence(struct seq_file *s, struct sync_fence *fence) +{ + struct list_head *pos; + unsigned long flags; + + seq_printf(s, "%s: %s\n", fence->name, sync_status_str(fence->status)); + + list_for_each(pos, &fence->pt_list_head) { + struct sync_pt *pt = + container_of(pos, struct sync_pt, pt_list); + sync_print_pt(s, pt, true); + } + + spin_lock_irqsave(&fence->waiter_list_lock, flags); + list_for_each(pos, &fence->waiter_list_head) { + struct sync_fence_waiter *waiter = + container_of(pos, struct sync_fence_waiter, + waiter_list); + + seq_printf(s, "waiter %pF %p\n", waiter->callback, + waiter->callback_data); + } + spin_unlock_irqrestore(&fence->waiter_list_lock, flags); +} + +static int sync_debugfs_show(struct seq_file *s, void *unused) +{ + unsigned long flags; + struct list_head *pos; + + seq_printf(s, "objs:\n--------------\n"); + + spin_lock_irqsave(&sync_timeline_list_lock, flags); + list_for_each(pos, &sync_timeline_list_head) { + struct sync_timeline *obj = + container_of(pos, struct sync_timeline, + sync_timeline_list); + + sync_print_obj(s, obj); + seq_printf(s, "\n"); + } + spin_unlock_irqrestore(&sync_timeline_list_lock, flags); + + seq_printf(s, "fences:\n--------------\n"); + + spin_lock_irqsave(&sync_fence_list_lock, flags); + list_for_each(pos, &sync_fence_list_head) { + struct sync_fence *fence = + container_of(pos, struct sync_fence, sync_fence_list); + + sync_print_fence(s, fence); + seq_printf(s, "\n"); + } + spin_unlock_irqrestore(&sync_fence_list_lock, flags); + return 0; +} + +static int sync_debugfs_open(struct inode *inode, struct file *file) +{ + return single_open(file, sync_debugfs_show, inode->i_private); +} + +static const struct file_operations sync_debugfs_fops = { + .open = sync_debugfs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static __init int sync_debugfs_init(void) +{ + debugfs_create_file("sync", S_IRUGO, NULL, NULL, &sync_debugfs_fops); + return 0; +} + +late_initcall(sync_debugfs_init); + +#endif diff --git a/include/linux/sync.h b/include/linux/sync.h index b9ee821..e1a20c4 100644 --- a/include/linux/sync.h +++ b/include/linux/sync.h @@ -41,6 +41,10 @@ struct sync_fence; * must be callable from atomic context * @free_pt: called before sync_pt is freed * @release_obj: called before sync_timeline is freed + * @print_obj: print aditional debug information about sync_timeline. + * should not print a newline + * @print_pt: print aditional debug information about sync_pt. + * should not print a newline */ struct sync_timeline_ops { const char *driver_name; @@ -59,6 +63,13 @@ struct sync_timeline_ops {
/* optional */ void (*release_obj)(struct sync_timeline *sync_timeline); + + /* optional */ + void (*print_obj)(struct seq_file *s, + struct sync_timeline *sync_timeline); + + /* optional */ + void (*print_pt)(struct seq_file *s, struct sync_pt *sync_pt); };
/** @@ -70,6 +81,7 @@ struct sync_timeline_ops { * @child_list_lock: lock protecting @child_list_head, destroyed, and * sync_pt.status * @active_list_head: list of active (unsignaled/errored) sync_pts + * @sync_timeline_list: membership in global sync_timeline_list */ struct sync_timeline { const struct sync_timeline_ops *ops; @@ -83,6 +95,8 @@ struct sync_timeline {
struct list_head active_list_head; spinlock_t active_list_lock; + + struct list_head sync_timeline_list; };
/** @@ -122,6 +136,7 @@ struct sync_pt { * @status: 1: signaled, 0:active, <0: error * * @wq: wait queue for fence signaling + * @sync_fence_list: membership in global fence list */ struct sync_fence { struct file *file; @@ -135,6 +150,8 @@ struct sync_fence { int status;
wait_queue_head_t wq; + + struct list_head sync_fence_list; };
/** @@ -283,9 +300,6 @@ int sync_fence_wait_async(struct sync_fence *fence, */ int sync_fence_wait(struct sync_fence *fence, long timeout);
-/* useful for sync driver's debug print handlers */ -const char *sync_status_str(int status); - #endif /* __KERNEL__ */
/**