On Sat, Apr 20, 2024 at 01:15:45PM +0800, Dawei Li wrote:
> In general it's preferable to avoid placing cpumasks on the stack, as
> for large values of NR_CPUS these can consume significant amounts of
> stack space and make stack overflows more likely.
>
> Since the cpumask var resides in __init function, which means it's free
> of any concurrenct access, it can be safely marked with static to get
> rid of allocation on stack.
>
> while at it, mark it with __initdata to keep it from persistently
> consumed memory.
I do not see the need for this - it does not fix a bug and it
complicates things.
If the size is a real concern the normal pattern is to allocate
and not declare it __initdata.
Yes - __initdata is used in some place.
I suggest to leave it as is unless we are fixing a real bug here.
Sam
>
> Signed-off-by: Dawei Li <dawei.li@xxxxxxxxxxxx>
> ---
> arch/sparc/mm/init_64.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
> index 1ca9054d9b97..088d9c103dcc 100644
> --- a/arch/sparc/mm/init_64.c
> +++ b/arch/sparc/mm/init_64.c
> @@ -1438,7 +1438,7 @@ static int __init numa_attach_mlgroup(struct mdesc_handle *md, u64 grp,
> static int __init numa_parse_mdesc_group(struct mdesc_handle *md, u64 grp,
> int index)
> {
> - cpumask_t mask;
> + static cpumask_t mask __initdata;
> int cpu;
>
> numa_parse_mdesc_group_cpus(md, grp, &mask);
> --
> 2.27.0
