Re: [PATCH v2 4/8] powernv/memtrace: always online added memory blocks

Wei Yang
2020-03-17T22:05:04Z

On Tue, Mar 17, 2020 at 11:49:38AM +0100, David Hildenbrand wrote:
>Let's always try to online the re-added memory blocks. In case add_memory()
>already onlined the added memory blocks, the first device_online() call
>will fail and stop processing the remaining memory blocks.
>
>This avoids manually having to check memhp_auto_online.
>
>Note: PPC always onlines all hotplugged memory directly from the kernel
>as well - something that is handled by user space on other
>architectures.
>
>Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>Cc: Paul Mackerras <paulus@samba.org>
>Cc: Michael Ellerman <mpe@ellerman.id.au>
>Cc: Andrew Morton <akpm@linux-foundation.org>
>Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>Cc: Michal Hocko <mhocko@kernel.org>
>Cc: Oscar Salvador <osalvador@suse.de>
>Cc: "Rafael J. Wysocki" <rafael@kernel.org>
>Cc: Baoquan He <bhe@redhat.com>
>Cc: Wei Yang <richard.weiyang@gmail.com>
>Cc: linuxppc-dev@lists.ozlabs.org
>Signed-off-by: David Hildenbrand <david@redhat.com>

Looks good.

Reviewed-by: Wei Yang <richard.weiyang@gmail.com>

>---
> arch/powerpc/platforms/powernv/memtrace.c | 14 ++++----------
> 1 file changed, 4 insertions(+), 10 deletions(-)
>
>diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
>index d6d64f8718e6..13b369d2cc45 100644
>--- a/arch/powerpc/platforms/powernv/memtrace.c
>+++ b/arch/powerpc/platforms/powernv/memtrace.c
>@@ -231,16 +231,10 @@ static int memtrace_online(void)
> continue;
> }
>
>- /*
>- * If kernel isn't compiled with the auto online option
>- * we need to online the memory ourselves.
>- */
>- if (!memhp_auto_online) {
>- lock_device_hotplug();
>- walk_memory_blocks(ent->start, ent->size, NULL,
>- online_mem_block);
>- unlock_device_hotplug();
>- }
>+ lock_device_hotplug();
>+ walk_memory_blocks(ent->start, ent->size, NULL,
>+ online_mem_block);
>+ unlock_device_hotplug();
>
> /*
> * Memory was added successfully so clean up references to it
>--
>2.24.1

--
Wei Yang
Help you, Help me