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

From: Mike Rapoport
Date: Tue Jan 30 2024 - 04:12:02 EST


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@xxxxxxxxx>
> ---
> 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

> 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
>
>

--
Sincerely yours,
Mike.