Re: [PATCH] mm/mmap: use SZ_{8M, 128M} helper macro

[Yajun Deng <yajun.deng@linux.dev>]

On 2024/1/30 17:11, Mike Rapoport wrote:
> On Fri, Jan 26, 2024 at 04:59:05PM +0800, Yajun Deng wrote:
>> Use SZ_{8M, 128M} macro intead of the number in init_user_reserve and
>> reserve_mem_notifier.
>>
>> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
>> ---
>>   mm/mmap.c | 8 ++++----
>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/mm/mmap.c b/mm/mmap.c
>> index 476de5daf598..f90924b2a6d2 100644
>> --- a/mm/mmap.c
>> +++ b/mm/mmap.c
>> @@ -3845,7 +3845,7 @@ static int init_user_reserve(void)
>>   
>>   	free_kbytes = K(global_zone_page_state(NR_FREE_PAGES));
>>   
>> -	sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17);
>> +	sysctl_user_reserve_kbytes = min(free_kbytes / 32, SZ_128M);
> (1UL << 17) != SZ_128M
I am sorry for this, I didn't realize that the unit was kbyte.
>
>>   	return 0;
>>   }
>>   subsys_initcall(init_user_reserve);
>> @@ -3866,7 +3866,7 @@ static int init_admin_reserve(void)
>>   
>>   	free_kbytes = K(global_zone_page_state(NR_FREE_PAGES));
>>   
>> -	sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13);
>> +	sysctl_admin_reserve_kbytes = min(free_kbytes / 32, SZ_8M);
>>   	return 0;
>>   }
>>   subsys_initcall(init_admin_reserve);
>> @@ -3898,12 +3898,12 @@ static int reserve_mem_notifier(struct notifier_block *nb,
>>   	case MEM_ONLINE:
>>   		/* Default max is 128MB. Leave alone if modified by operator. */
>>   		tmp = sysctl_user_reserve_kbytes;
>> -		if (0 < tmp && tmp < (1UL << 17))
>> +		if (tmp > 0 && tmp < SZ_128M)
>>   			init_user_reserve();
>>   
>>   		/* Default max is 8MB.  Leave alone if modified by operator. */
>>   		tmp = sysctl_admin_reserve_kbytes;
>> -		if (0 < tmp && tmp < (1UL << 13))
>> +		if (tmp > 0 && tmp < SZ_8M)
> (1UL << 13) != SZ_8M
>
>>   			init_admin_reserve();
>>   
>>   		break;
>> -- 
>> 2.25.1
>>
>>