[patch 066/166] powernv/memtrace: always online added memory blocks

Andrew Morton
2020-04-07T03:07:32Z

From: David Hildenbrand <david@redhat.com>
Subject: powernv/memtrace: always online added memory blocks

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.

Link: http://lkml.kernel.org/r/20200317104942.11178-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

arch/powerpc/platforms/powernv/memtrace.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)

--- a/arch/powerpc/platforms/powernv/memtrace.c~powernv-memtrace-always-online-added-memory-blocks
+++ a/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
_