Re: Cannot hot remove a memory device

["Rafael J. Wysocki" <rjw@sisk.pl>]

Hi,

Thanks for your report.

On Thursday, August 01, 2013 05:37:21 PM Yasuaki Ishimatsu wrote:
> By following commit, I cannot hot remove a memory device.
> 
> ACPI / memhotplug: Bind removable memory blocks to ACPI device nodes
> commit e2ff39400d81233374e780b133496a2296643d7d
> 
> Details are follows:
> When I add a memory device, acpi_memory_enable_device() always fails
> as follows:
> 
> ...
> [ 1271.114116]  [ffffea121c400000-ffffea121c7fffff] PMD -> [ffff880813c00000-ffff880813ffffff] on node 3
> [ 1271.128682]  [ffffea121c800000-ffffea121cbfffff] PMD -> [ffff880813800000-ffff880813bfffff] on node 3
> [ 1271.143298]  [ffffea121cc00000-ffffea121cffffff] PMD -> [ffff880813000000-ffff8808133fffff] on node 3
> [ 1271.157799]  [ffffea121d000000-ffffea121d3fffff] PMD -> [ffff880812c00000-ffff880812ffffff] on node 3
> [ 1271.172341]  [ffffea121d400000-ffffea121d7fffff] PMD -> [ffff880812800000-ffff880812bfffff] on node 3
> [ 1271.186872]  [ffffea121d800000-ffffea121dbfffff] PMD -> [ffff880812400000-ffff8808127fffff] on node 3
> [ 1271.201481]  [ffffea121dc00000-ffffea121dffffff] PMD -> [ffff880812000000-ffff8808123fffff] on node 3
> [ 1271.216041]  [ffffea121e000000-ffffea121e3fffff] PMD -> [ffff880811c00000-ffff880811ffffff] on node 3
> [ 1271.230623]  [ffffea121e400000-ffffea121e7fffff] PMD -> [ffff880811800000-ffff880811bfffff] on node 3
> [ 1271.245148]  [ffffea121e800000-ffffea121ebfffff] PMD -> [ffff880811400000-ffff8808117fffff] on node 3
> [ 1271.259683]  [ffffea121ec00000-ffffea121effffff] PMD -> [ffff880811000000-ffff8808113fffff] on node 3
> [ 1271.274194]  [ffffea121f000000-ffffea121f3fffff] PMD -> [ffff880810c00000-ffff880810ffffff] on node 3
> [ 1271.288764]  [ffffea121f400000-ffffea121f7fffff] PMD -> [ffff880810800000-ffff880810bfffff] on node 3
> ...	
> [ 1271.325841] acpi PNP0C80:03: acpi_memory_enable_device() error

Well, the only new way acpi_memory_enable_device() can fail after that commit
is a failure in acpi_bind_memory_blocks().

This means that either handle is NULL, which I think we can exclude, because
acpi_memory_enable_device() wouldn't be called at all if that were the case, or
there's a more subtle error in acpi_bind_one().

One that comes to mind is that we may be calling acpi_bind_one() twice for the
same memory region, in which it will trigger -EINVAL from the sanity check in
there.

Also you may try to increase ACPI_MAX_PHYSICAL_NODE (in acpi_bus.h) and see if
that helps.

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.