Re: [PATCH v2 1/4] mm: bypass mmap_miss heuristic for VM_EXEC readahead

Kiryl Shutsemau
2026-03-20T14:26:58Z

On Fri, Mar 20, 2026 at 06:58:51AM -0700, Usama Arif wrote:
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 6cd7974d4adab..7d89c6b384cc4 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -3331,7 +3331,7 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf)
> }
> }
>
> - if (!(vm_flags & VM_SEQ_READ)) {
> + if (!(vm_flags & (VM_SEQ_READ | VM_EXEC))) {

Strictly speaking the fact that the file mapped as executable doesn't
mean we are serving instruction fetch page fault.

FAULT_FLAG_INSTRUCTION would be the signal, but it is only provided by
handful of architectures.

VM_EXEC is good enough proxy.

Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>

--
Kiryl Shutsemau / Kirill A. Shutemov