Messages in this thread | | | Date | Tue, 30 Jul 2019 08:46:57 +0200 | From | Greg KH <> | Subject | Re: [PATCH v5] PM / wakeup: show wakeup sources stats in sysfs |
| |
On Mon, Jul 29, 2019 at 07:43:09PM -0700, Tri Vo wrote: > Userspace can use wakeup_sources debugfs node to plot history of suspend > blocking wakeup sources over device's boot cycle. This information can > then be used (1) for power-specific bug reporting and (2) towards > attributing battery consumption to specific processes over a period of > time. > > However, debugfs doesn't have stable ABI. For this reason, create a > 'struct device' to expose wakeup sources statistics in sysfs under > /sys/class/wakeup/wakeup<ID>/*.
I agree with Rafael here, no need for the extra "wakeup" in the device name as you are in the "wakeup" namespace already.
If you have an IDA-allocated name, there's no need for the extra 'wakeup' at all.
> +int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws) > +{ > + struct device *dev; > + int id; > + > + id = ida_simple_get(&wakeup_ida, 0, 0, GFP_KERNEL); > + if (id < 0) > + return id;
No lock needed for this ida? Are you sure?
> + ws->id = id; > + > + dev = device_create_with_groups(wakeup_class, parent, MKDEV(0, 0), ws, > + wakeup_source_groups, "wakeup%d", > + ws->id); > + if (IS_ERR(dev)) { > + ida_simple_remove(&wakeup_ida, ws->id); > + return PTR_ERR(dev); > + } > + > + ws->dev = dev; > + return 0; > +} > +EXPORT_SYMBOL_GPL(wakeup_source_sysfs_add); > + > +/** > + * wakeup_source_sysfs_remove - Remove wakeup_source attributes from sysfs. > + * @ws: Wakeup source to be removed from sysfs. > + */ > +void wakeup_source_sysfs_remove(struct wakeup_source *ws) > +{ > + device_unregister(ws->dev); > + ida_simple_remove(&wakeup_ida, ws->id);
Again, no lock, is that ok? I think ida's can work without a lock, but not always, sorry, I don't remember the rules anymore given the recent changes in that code.
thanks,
greg k-h
| |