Reviewed-by: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
On 8/21/18 6:44 AM, David Hildenbrand wrote:
> Let's perform all checking + offlining + removing under
> device_hotplug_lock, so nobody can mess with these devices via
> sysfs concurrently.
>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Rashmica Gupta <rashmica.g@xxxxxxxxx>
> Cc: Balbir Singh <bsingharora@xxxxxxxxx>
> Cc: Michael Neuling <mikey@xxxxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
> arch/powerpc/platforms/powernv/memtrace.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
> index ef7181d4fe68..473e59842ec5 100644
> --- a/arch/powerpc/platforms/powernv/memtrace.c
> +++ b/arch/powerpc/platforms/powernv/memtrace.c
> @@ -74,9 +74,13 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages)
> {
> u64 end_pfn = start_pfn + nr_pages - 1;
>
> + lock_device_hotplug();
> +
> if (walk_memory_range(start_pfn, end_pfn, NULL,
> - check_memblock_online))
> + check_memblock_online)) {
> + unlock_device_hotplug();
> return false;
> + }
>
> walk_memory_range(start_pfn, end_pfn, (void *)MEM_GOING_OFFLINE,
> change_memblock_state);
> @@ -84,14 +88,16 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages)
> if (offline_pages(start_pfn, nr_pages)) {
> walk_memory_range(start_pfn, end_pfn, (void *)MEM_ONLINE,
> change_memblock_state);
> + unlock_device_hotplug();
> return false;
> }
>
> walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE,
> change_memblock_state);
>
> - remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
> + __remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
>
> + unlock_device_hotplug();
> return true;
> }
>
>
