Messages in this thread | | | From | KOSAKI Motohiro <> | Date | Thu, 11 Oct 2012 18:33:23 -0400 | Subject | Re: [PATCH 2/2]suppress "Device nodeX does not have a release() function" warning |
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On Thu, Oct 11, 2012 at 1:26 AM, Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> wrote: > When calling unregister_node(), the function shows following message at > device_release(). > > "Device 'node2' does not have a release() function, it is broken and must > be fixed." > > The reason is node's device struct does not have a release() function. > > So the patch registers node_device_release() to the device's release() > function for suppressing the warning message. Additionally, the patch adds > memset() to initialize a node struct into register_node(). Because the node > struct is part of node_devices[] array and it cannot be freed by > node_device_release(). So if system reuses the node struct, it has a garbage. > > CC: David Rientjes <rientjes@google.com> > CC: Jiang Liu <liuj97@gmail.com> > Cc: Minchan Kim <minchan.kim@gmail.com> > CC: Andrew Morton <akpm@linux-foundation.org> > CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> > Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> > --- > drivers/base/node.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > Index: linux-3.6/drivers/base/node.c > =================================================================== > --- linux-3.6.orig/drivers/base/node.c 2012-10-11 10:04:02.149758748 +0900 > +++ linux-3.6/drivers/base/node.c 2012-10-11 10:20:34.111806931 +0900 > @@ -252,6 +252,14 @@ static inline void hugetlb_register_node > static inline void hugetlb_unregister_node(struct node *node) {} > #endif > > +static void node_device_release(struct device *dev) > +{ > +#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HUGETLBFS) > + struct node *node_dev = to_node(dev); > + > + flush_work(&node_dev->node_work); > +#endif > +}
The patch description don't explain why this flush_work() is needed.
> /* > * register_node - Setup a sysfs device for a node. > @@ -263,8 +271,11 @@ int register_node(struct node *node, int > { > int error; > > + memset(node, 0, sizeof(*node)); > +
You should add a comment why we need initialize a node here. A lot of developers don't have hotplug knowledge.
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