hulk inclusion category: performance bugzilla: https://gitee.com/openeuler/kernel/issues/I9N68A CVE: NA

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After committing df0ad0579ac9 (‘mm: align larger anonymous mappings on THP boundaries’), memory read latency increased significantly on arm64 but not x86_64, so it's temporarily disabled on arm64 and we'll turn it back on once it's fixed.

Signed-off-by: Ze Zuo zuoze1@huawei.com --- mm/mmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/mmap.c b/mm/mmap.c index 6cd5d3f607e5..77e66c5a1f46 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1848,7 +1848,8 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, * so use shmem's get_unmapped_area in case it can be huge. */ get_area = shmem_get_unmapped_area; - } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { + } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + !IS_ENABLED(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)) { /* Ensures that larger anonymous mappings are THP aligned. */ get_area = thp_get_unmapped_area; }