Re: [PATCH v5 2/3] kernel/fork.c: get totalram_pages from memblock to calculate max_threads

[Mike Rapoport]

On Tue, Jul 09, 2024 at 02:36:08AM +0000, Wei Yang wrote:
> Since we plan to move the accounting into __free_pages_core(),
> totalram_pages may not represent the total usable pages on system
> at this point when defer_init is enabled.
> 
> Instead we can get the total estimated pages from memblock directly.
> 
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> CC: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
> CC: David Hildenbrand <david@xxxxxxxxxx>
> CC: Oleg Nesterov <oleg@xxxxxxxxxx>

Acked-by: Mike Rapoport <rppt@xxxxxxxxxx>

> ---
>  kernel/fork.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 279efadabbf2..d6c2a4ccd532 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -44,6 +44,7 @@
>  #include <linux/fs.h>
>  #include <linux/mm.h>
>  #include <linux/mm_inline.h>
> +#include <linux/memblock.h>
>  #include <linux/nsproxy.h>
>  #include <linux/capability.h>
>  #include <linux/cpu.h>
> @@ -999,7 +1000,7 @@ void __init __weak arch_task_cache_init(void) { }
>  static void set_max_threads(unsigned int max_threads_suggested)
>  {
>  	u64 threads;
> -	unsigned long nr_pages = totalram_pages();
> +	unsigned long nr_pages = memblock_estimated_nr_free_pages();
>  
>  	/*
>  	 * The number of threads shall be limited such that the thread
> -- 
> 2.34.1
> 

-- 
Sincerely yours,
Mike.