On 2024/3/19 0:33, Mike Rapoport wrote:
> On Mon, Mar 18, 2024 at 09:57:14PM +0800, thunder.leizhen@xxxxxxxxxxxxxxx wrote:
>> From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
>>
>> The local variable 'page_poisoning_requested' is assigned true at only
>> one point. It can be eliminated by moving the code that depends on it
>> to the location where it is assigned true. This also make the moved
>> code to be compiled only if CONFIG_PAGE_POISONING is set.
>
> I don't see it as much of an improvement and code readability becomes worse
> IMO.
Yes, the moved branch will be optimized by the compiler if CONFIG_PAGE_POISONING is
not set. But for a reader, he can simply skip over that moved branch when
CONFIG_PAGE_POISONING is not set.
>
>> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
>> ---
>> mm/mm_init.c | 17 +++++++----------
>> 1 file changed, 7 insertions(+), 10 deletions(-)
>>
>> diff --git a/mm/mm_init.c b/mm/mm_init.c
>> index 549e76af8f82a8e..3eb217130bcb2b5 100644
>> --- a/mm/mm_init.c
>> +++ b/mm/mm_init.c
>> @@ -2614,7 +2614,6 @@ DEFINE_STATIC_KEY_MAYBE(CONFIG_DEBUG_VM, check_pages_enabled);
>> */
>> static void __init mem_debugging_and_hardening_init(void)
>> {
>> - bool page_poisoning_requested = false;
>> bool want_check_pages = false;
>>
>> #ifdef CONFIG_PAGE_POISONING
>> @@ -2626,18 +2625,16 @@ static void __init mem_debugging_and_hardening_init(void)
>> (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
>> debug_pagealloc_enabled())) {
>> static_branch_enable(&_page_poisoning_enabled);
>> - page_poisoning_requested = true;
>> want_check_pages = true;
>> - }
>> -#endif
>>
>> - if ((_init_on_alloc_enabled_early || _init_on_free_enabled_early) &&
>> - page_poisoning_requested) {
>> - pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
>> - "will take precedence over init_on_alloc and init_on_free\n");
>> - _init_on_alloc_enabled_early = false;
>> - _init_on_free_enabled_early = false;
>> + if (_init_on_alloc_enabled_early || _init_on_free_enabled_early) {
>> + pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, "
>> + "will take precedence over init_on_alloc and init_on_free\n");
>> + _init_on_alloc_enabled_early = false;
>> + _init_on_free_enabled_early = false;
>> + }
>> }
>> +#endif
>>
>> if (_init_on_alloc_enabled_early) {
>> want_check_pages = true;
>> --
>> 2.34.1
>>
>
--
Regards,
Zhen Lei
