2019-09-26 10:19:47

by Alastair D'Silva

[permalink] [raw]
Subject: [PATCH v4 6/6] powerpc: Don't flush caches when adding memory

From: Alastair D'Silva <[email protected]>

This operation takes a significant amount of time when hotplugging
large amounts of memory (~50 seconds with 890GB of persistent memory).

This was orignally in commit fb5924fddf9e
("powerpc/mm: Flush cache on memory hot(un)plug") to support memtrace,
but the flush on add is not needed as it is flushed on remove.

Signed-off-by: Alastair D'Silva <[email protected]>
---
arch/powerpc/mm/mem.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index a2758e473d58..9afb77a8c8d5 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -142,8 +142,6 @@ int __ref arch_add_memory(int nid, u64 start, u64 size,
return -EFAULT;
}

- flush_dcache_range_chunked(start, start + size, FLUSH_CHUNK_SIZE);
-
return __add_pages(nid, start_pfn, nr_pages, restrictions);
}

--
2.21.0