lkml.org 
[lkml]   [2012]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC PATCH v4 12/13] memory-hotplug : add node_device_release
    At 07/18/2012 06:17 PM, Yasuaki Ishimatsu 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.
    >
    > So the patch implements node_device_release()
    >
    > CC: David Rientjes <rientjes@google.com>
    > CC: Jiang Liu <liuj97@gmail.com>
    > CC: Len Brown <len.brown@intel.com>
    > CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    > CC: Paul Mackerras <paulus@samba.org>
    > CC: Christoph Lameter <cl@linux.com>
    > Cc: Minchan Kim <minchan.kim@gmail.com>
    > CC: Andrew Morton <akpm@linux-foundation.org>
    > CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    > CC: Wen Congyang <wency@cn.fujitsu.com>
    > Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
    >
    > ---
    > drivers/base/node.c | 7 +++++++
    > 1 file changed, 7 insertions(+)
    >
    > Index: linux-3.5-rc6/drivers/base/node.c
    > ===================================================================
    > --- linux-3.5-rc6.orig/drivers/base/node.c 2012-07-18 18:24:29.191121066 +0900
    > +++ linux-3.5-rc6/drivers/base/node.c 2012-07-18 18:25:47.111146983 +0900
    > @@ -252,6 +252,12 @@ static inline void hugetlb_register_node
    > static inline void hugetlb_unregister_node(struct node *node) {}
    > #endif
    >
    > +static void node_device_release(struct device *dev)
    > +{
    > + struct node *node_dev = to_node(dev);
    > +
    > + memset(node_dev, 0, sizeof(struct node));

    This line is wrong. node_dev->work_struct may be queued in workqueue.
    So, it is very dangerous to clear node_dev->work_struct here.
    In my test, it will cause kernel panicked.

    Thanks
    Wen Congyang
    > +}
    >
    > /*
    > * register_node - Setup a sysfs device for a node.
    > @@ -265,6 +271,7 @@ int register_node(struct node *node, int
    >
    > node->dev.id = num;
    > node->dev.bus = &node_subsys;
    > + node->dev.release = node_device_release;
    > error = device_register(&node->dev);
    >
    > if (!error){
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html
    > Please read the FAQ at http://www.tux.org/lkml/
    >



    \
     
     \ /
      Last update: 2012-07-27 09:01    [W:0.049 / U:12.204 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site