From: Kefeng Wang <wangkefeng.wang@huawei.com> hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I98AW9 CVE: NA ------------------------------------------------- Let's document the new thp_mapping_align sysfs interfaces for transhuge. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- Documentation/admin-guide/mm/transhuge.rst | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index 22f0e0009371..e52cd57bb512 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -211,6 +211,15 @@ possible to enable/disable it by configurate the corresponding bit:: echo 0x2 >/sys/kernel/mm/transparent_hugepage/thp_exec_enabled echo 0x3 >/sys/kernel/mm/transparent_hugepage/thp_exec_enabled +The kernel could try to enable other larger size mappings align other +than THP size, eg, 64K on arm64, BIT0 for file mapping, BIT1 for anon +mapping, it is disabled by default, and could enable this feature by +writing the corresponding bit to 1:: + + echo 0x1 >/sys/kernel/mm/transparent_hugepage/thp_mapping_align + echo 0x2 >/sys/kernel/mm/transparent_hugepage/thp_mapping_align + echo 0x3 >/sys/kernel/mm/transparent_hugepage/thp_mapping_align + khugepaged will be automatically started when one or more hugepage sizes are enabled (either by directly setting "always" or "madvise", or by setting "inherit" while the top-level enabled is set to "always" -- 2.39.2