Em Tue, 14 Aug 2018 09:33:16 +0200
Hans Verkuil <hverk...@xs4all.nl> escreveu:
> On 13/08/18 17:15, Mauro Carvalho Chehab wrote:
> > Em Sat, 4 Aug 2018 14:45:26 +0200
> > Hans Verkuil <hverk...@xs4all.nl> escreveu:
> >
> >> From: Hans Verkuil <hans.verk...@cisco.com>
> >>
> >> Keep track of the number of requests and request objects of a media
> >> device. Helps to verify that all request-related memory is freed.
Ok. So, let's skip it on your next patchset. Debugfs can
be added any time after the requests API main patchset gets merged.
> >>
> >> Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
> >
> >
> >
> >> ---
> >> drivers/media/media-device.c | 41 +++++++++++++++++++++++++++++++++++
> >> drivers/media/media-devnode.c | 17 +++++++++++++++
> >> drivers/media/media-request.c | 5 +++++
> >> include/media/media-device.h | 11 ++++++++++
> >> include/media/media-devnode.h | 4 ++++
> >> include/media/media-request.h | 2 ++
> >> 6 files changed, 80 insertions(+)
> >>
> >> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> >> index 4b9a8de05562..28a891b53886 100644
> >> --- a/drivers/media/media-device.c
> >> +++ b/drivers/media/media-device.c
> >> @@ -691,6 +691,23 @@ void media_device_unregister_entity(struct
> >> media_entity *entity)
> >> }
> >> EXPORT_SYMBOL_GPL(media_device_unregister_entity);
> >>
> >> +#ifdef CONFIG_DEBUG_FS
> >
> > Patch itself looks good. Yet, perhaps we could request both
> > CONFIG_DEBUG_FS and CONFIG_VIDEO_ADV_DEBUG.
> >
> > Also, instead of ifdef, please use IS_ENABLED for DEBUG_FS. That tends
> > to be safer long term.
> >
> > With that:
> >
> > Reviewed-by: Mauro Carvalho Chehab <mchehab+sams...@kernel.org>
>
> I don't intend to merge this patch yet. I'm not happy with it: I would
> really like to count the objects per-request instead of globally, and
> provide some more information about requests and their objects.
>
> It was really a quick hack so that I could verify that all requests and
> objects are properly freed.
>
> Regards,
>
> Hans
>
> >
> >> +/*
> >> + * Log the state of media requests.
> >> + * Very useful for debugging.
> >> + */
> >> +static int media_device_requests(struct seq_file *file, void *priv)
> >> +{
> >> + struct media_device *dev = dev_get_drvdata(file->private);
> >> +
> >> + seq_printf(file, "number of requests: %d\n",
> >> + atomic_read(&dev->num_requests));
> >> + seq_printf(file, "number of request objects: %d\n",
> >> + atomic_read(&dev->num_request_objects));
> >> + return 0;
> >> +}
> >> +#endif
> >> +
> >> /**
> >> * media_device_init() - initialize a media device
> >> * @mdev: The media device
> >> @@ -713,6 +730,9 @@ void media_device_init(struct media_device *mdev)
> >> mutex_init(&mdev->graph_mutex);
> >> ida_init(&mdev->entity_internal_idx);
> >>
> >> + atomic_set(&mdev->num_requests, 0);
> >> + atomic_set(&mdev->num_request_objects, 0);
> >> +
> >> dev_dbg(mdev->dev, "Media device initialized\n");
> >> }
> >> EXPORT_SYMBOL_GPL(media_device_init);
> >> @@ -764,6 +784,26 @@ int __must_check __media_device_register(struct
> >> media_device *mdev,
> >>
> >> dev_dbg(mdev->dev, "Media device registered\n");
> >>
> >> +#ifdef CONFIG_DEBUG_FS
> >> + if (!media_top_dir)
> >> + return 0;
> >> +
> >> + mdev->media_dir = debugfs_create_dir(dev_name(&devnode->dev),
> >> + media_top_dir);
> >> + if (IS_ERR_OR_NULL(mdev->media_dir)) {
> >> + dev_warn(mdev->dev, "Failed to create debugfs dir\n");
> >> + return 0;
> >> + }
> >> + mdev->requests_file = debugfs_create_devm_seqfile(&devnode->dev,
> >> + "requests", mdev->media_dir, media_device_requests);
> >> + if (IS_ERR_OR_NULL(mdev->requests_file)) {
> >> + dev_warn(mdev->dev, "Failed to create requests file\n");
> >> + debugfs_remove_recursive(mdev->media_dir);
> >> + mdev->media_dir = NULL;
> >> + return 0;
> >> + }
> >> +#endif
> >> +
> >> return 0;
> >> }
> >> EXPORT_SYMBOL_GPL(__media_device_register);
> >> @@ -841,6 +881,7 @@ void media_device_unregister(struct media_device *mdev)
> >>
> >> dev_dbg(mdev->dev, "Media device unregistered\n");
> >>
> >> + debugfs_remove_recursive(mdev->media_dir);
> >> device_remove_file(&mdev->devnode->dev, &dev_attr_model);
> >> media_devnode_unregister(mdev->devnode);
> >> /* devnode free is handled in media_devnode_*() */
> >> diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c
> >> index 6b87a721dc49..4358ed22f208 100644
> >> --- a/drivers/media/media-devnode.c
> >> +++ b/drivers/media/media-devnode.c
> >> @@ -53,6 +53,12 @@ static dev_t media_dev_t;
> >> static DEFINE_MUTEX(media_devnode_lock);
> >> static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES);
> >>
> >> +/*
> >> + * debugfs
> >> + */
> >> +struct dentry *media_top_dir;
> >> +
> >> +
> >> /* Called when the last user of the media device exits. */
> >> static void media_devnode_release(struct device *cd)
> >> {
> >> @@ -259,6 +265,8 @@ int __must_check media_devnode_register(struct
> >> media_device *mdev,
> >> goto cdev_add_error;
> >> }
> >>
> >> + dev_set_drvdata(&devnode->dev, mdev);
> >> +
> >> /* Part 4: Activate this minor. The char device can now be used. */
> >> set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
> >>
> >> @@ -310,6 +318,14 @@ static int __init media_devnode_init(void)
> >> return ret;
> >> }
> >>
> >> +#ifdef CONFIG_DEBUG_FS
> >> + media_top_dir = debugfs_create_dir("media", NULL);
> >> + if (IS_ERR_OR_NULL(media_top_dir)) {
> >> + pr_warn("Failed to create debugfs media dir\n");
> >> + media_top_dir = NULL;
> >> + }
> >> +#endif
> >> +
> >> ret = bus_register(&media_bus_type);
> >> if (ret < 0) {
> >> unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
> >> @@ -322,6 +338,7 @@ static int __init media_devnode_init(void)
> >>
> >> static void __exit media_devnode_exit(void)
> >> {
> >> + debugfs_remove_recursive(media_top_dir);
> >> bus_unregister(&media_bus_type);
> >> unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
> >> }
> >> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
> >> index a5b70a4e613b..8ba97a9c4bf1 100644
> >> --- a/drivers/media/media-request.c
> >> +++ b/drivers/media/media-request.c
> >> @@ -72,6 +72,7 @@ static void media_request_release(struct kref *kref)
> >> mdev->ops->req_free(req);
> >> else
> >> kfree(req);
> >> + atomic_dec(&mdev->num_requests);
> >> }
> >>
> >> void media_request_put(struct media_request *req)
> >> @@ -318,6 +319,7 @@ int media_request_alloc(struct media_device *mdev,
> >> get_task_comm(comm, current);
> >> snprintf(req->debug_str, sizeof(req->debug_str), "%s:%d",
> >> comm, fd);
> >> + atomic_inc(&mdev->num_requests);
> >> dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
> >>
> >> fd_install(fd, filp);
> >> @@ -342,6 +344,7 @@ static void media_request_object_release(struct kref
> >> *kref)
> >> if (WARN_ON(req))
> >> media_request_object_unbind(obj);
> >> obj->ops->release(obj);
> >> + atomic_dec(&obj->mdev->num_request_objects);
> >> }
> >>
> >> struct media_request_object *
> >> @@ -405,10 +408,12 @@ int media_request_object_bind(struct media_request
> >> *req,
> >> obj->req = req;
> >> obj->ops = ops;
> >> obj->priv = priv;
> >> + obj->mdev = req->mdev;
> >>
> >> list_add_tail(&obj->list, &req->objects);
> >> req->num_incomplete_objects++;
> >> ret = 0;
> >> + atomic_inc(&obj->mdev->num_request_objects);
> >>
> >> unlock:
> >> spin_unlock_irqrestore(&req->lock, flags);
> >> diff --git a/include/media/media-device.h b/include/media/media-device.h
> >> index 110b89567671..2de0606938d4 100644
> >> --- a/include/media/media-device.h
> >> +++ b/include/media/media-device.h
> >> @@ -21,6 +21,7 @@
> >>
> >> #include <linux/list.h>
> >> #include <linux/mutex.h>
> >> +#include <linux/atomic.h>
> >>
> >> #include <media/media-devnode.h>
> >> #include <media/media-entity.h>
> >> @@ -107,6 +108,10 @@ struct media_device_ops {
> >> * @ops: Operation handler callbacks
> >> * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
> >> * other operations that stop or start streaming.
> >> + * @num_requests: number of associated requests
> >> + * @num_request_objects: number of associated request objects
> >> + * @media_dir: DebugFS media directory
> >> + * @requests_file: DebugFS requests file
> >> *
> >> * This structure represents an abstract high-level media device. It
> >> allows easy
> >> * access to entities and provides basic media device-level support. The
> >> @@ -179,6 +184,12 @@ struct media_device {
> >> const struct media_device_ops *ops;
> >>
> >> struct mutex req_queue_mutex;
> >> + atomic_t num_requests;
> >> + atomic_t num_request_objects;
> >> +
> >> + /* debugfs */
> >> + struct dentry *media_dir;
> >> + struct dentry *requests_file;
> >> };
> >>
> >> /* We don't need to include pci.h or usb.h here */
> >> diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h
> >> index dc2f64e1b08f..984b62b634d3 100644
> >> --- a/include/media/media-devnode.h
> >> +++ b/include/media/media-devnode.h
> >> @@ -28,9 +28,13 @@
> >> #include <linux/fs.h>
> >> #include <linux/device.h>
> >> #include <linux/cdev.h>
> >> +#include <linux/debugfs.h>
> >>
> >> struct media_device;
> >>
> >> +/* DebugFS top-level media directory */
> >> +extern struct dentry *media_top_dir;
> >> +
> >> /*
> >> * Flag to mark the media_devnode struct as registered. Drivers must not
> >> touch
> >> * this flag directly, it will be set and cleared by
> >> media_devnode_register and
> >> diff --git a/include/media/media-request.h b/include/media/media-request.h
> >> index fd08d7a431a1..76727d4a89c3 100644
> >> --- a/include/media/media-request.h
> >> +++ b/include/media/media-request.h
> >> @@ -210,6 +210,7 @@ struct media_request_object_ops {
> >> * struct media_request_object - An opaque object that belongs to a media
> >> * request
> >> *
> >> + * @mdev: Media device this object belongs to
> >> * @ops: object's operations
> >> * @priv: object's priv pointer
> >> * @req: the request this object belongs to (can be NULL)
> >> @@ -221,6 +222,7 @@ struct media_request_object_ops {
> >> * another struct that contains the actual data for this request object.
> >> */
> >> struct media_request_object {
> >> + struct media_device *mdev;
> >> const struct media_request_object_ops *ops;
> >> void *priv;
> >> struct media_request *req;
> >
> >
> >
> > Thanks,
> > Mauro
> >
>
Thanks,
Mauro
