x86/mm/tlb: Do not make is_lazy dirty for no reason

mainline inclusion
from mainline-v5.13-rc1
commit 09c5272e
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZV2C


CVE: NA

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

Blindly writing to is_lazy for no reason, when the written value is
identical to the old value, makes the cacheline dirty for no reason.
Avoid making such writes to prevent cache coherency traffic for no
reason.

Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20210220231712.2475218-7-namit@vmware.com


Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Chen Wandun <chenwandun@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>