hulk inclusion
category: performance
bugzilla: 187468, https://gitee.com/openeuler/kernel/issues/I61HVC

--------------------------------

Patch d8a759b5 ("mm, page_alloc: double zone's batchsize") change the
default batchsize. For some machines with large memory, the value seems to
be too large. Although percpu_pagelist_fraction can be used to revise the
batchsize but needs to be adjusted based on managed memory.
So add a new sysctl percpu_max_batchsize to revise the batchsize to adapt
different scenarios.
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>