Re: [PATCH 1/4] memory-hotplug: add memory_block_release

[Yasuaki Ishimatsu]

Hi Chen,

2012/09/27 19:20, Ni zhan Chen wrote:
> Hi Congyang,
>
> 2012/9/27 <wency@xxxxxxxxxxxxxx>
>
> > From: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
> >
> > When calling remove_memory_block(), the function shows following message at
> > device_release().
> >
> > Device 'memory528' does not have a release() function, it is broken and
> > must
> > be fixed.
>
> What's the difference between the patch and original implemetation?

The implementation is for removing a memory_block. So the purpose is
same as original one. But original code is bad manner. kobject_cleanup()
is called by remove_memory_block() at last. But release function for
releasing memory_block is not registered. As a result, the kernel message
is shown. IMHO, memory_block should be release by the releae function.

Thanks,
Yasuaki Ishimatsu

> > remove_memory_block() calls kfree(mem). I think it shouled be called from
> > device_release(). So the patch implements memory_block_release()
> >
> > CC: David Rientjes <rientjes@xxxxxxxxxx>
> > CC: Jiang Liu <liuj97@xxxxxxxxx>
> > CC: Len Brown <len.brown@xxxxxxxxx>
> > CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> > CC: Paul Mackerras <paulus@xxxxxxxxx>
> > Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
> > CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> > CC: Wen Congyang <wency@xxxxxxxxxxxxxx>
> > Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
> > ---
> >   drivers/base/memory.c |    9 ++++++++-
> >   1 files changed, 8 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> > index 7dda4f7..da457e5 100644
> > --- a/drivers/base/memory.c
> > +++ b/drivers/base/memory.c
> > @@ -70,6 +70,13 @@ void unregister_memory_isolate_notifier(struct
> > notifier_block *nb)
> >   }
> >   EXPORT_SYMBOL(unregister_memory_isolate_notifier);
> >
> > +static void release_memory_block(struct device *dev)
> > +{
> > +       struct memory_block *mem = container_of(dev, struct memory_block,
> > dev);
> > +
> > +       kfree(mem);
> > +}
> > +
> >   /*
> >    * register_memory - Setup a sysfs device for a memory block
> >    */
> > @@ -80,6 +87,7 @@ int register_memory(struct memory_block *memory)
> >
> >          memory->dev.bus = &memory_subsys;
> >          memory->dev.id = memory->start_section_nr / sections_per_block;
> > +       memory->dev.release = release_memory_block;
> >
> >          error = device_register(&memory->dev);
> >          return error;
> > @@ -630,7 +638,6 @@ int remove_memory_block(unsigned long node_id, struct
> > mem_section *section,
> >                  mem_remove_simple_file(mem, phys_device);
> >                  mem_remove_simple_file(mem, removable);
> >                  unregister_memory(mem);
> > -               kfree(mem);
> >          } else
> >                  kobject_put(&mem->dev.kobj);
> >
> > --
> > 1.7.1
> >
> > --
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