Re: [PATCH v9 bpf-next 1/9] x86/Kconfig: select HAVE_ARCH_HUGE_VMALLOC with HAVE_ARCH_HUGE_VMAP

On Tue, 2022-03-29 at 19:13 +0000, Song Liu wrote:

quoted

I don't think we should tie this to vmap_allow_huge by definition.
Also, what it does is try 2MB pages for allocations larger than
2MB.
For smaller allocations it doesn't try or "prefer" them.

How about something like:

#define VM_TRY_HUGE_VMAP        0x00001000      /* try PMD_SIZE
mapping if size-per-node >= PMD_SIZE */

Seems reasonable name. I don't know if "size-per-node >= PMD_SIZE" is
going to be useful information. Maybe something like:

/* Allow for huge pages on HAVE_ARCH_HUGE_VMALLOC_FLAG arch's */