From dd2b4e04c09808ff921e3460a608537d1a94595d Mon Sep 17 00:00:00 2001 From: Kevin Brodsky Date: Thu, 22 Jan 2026 17:02:21 +0000 Subject: selftests/mm: introduce helper to read every page FORCE_READ(*addr) ensures that the compiler will emit a load from addr. Several tests need to trigger such a load for a range of pages, ensuring that every page is faulted in, if it wasn't already. Introduce a new helper force_read_pages() that does exactly that and replace existing loops with a call to it. The step size (regular/huge page size) is preserved for all loops, except in split_huge_page_test. Reading every byte is unnecessary; we now read every huge page, matching the following call to check_huge_file(). Link: https://lkml.kernel.org/r/20260122170224.4056513-7-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Reviewed-by: Dev Jain Reviewed-by: Muhammad Usama Anjum Acked-by: David Hildenbrand (Red Hat) Cc: Jason Gunthorpe Cc: John Hubbard Cc: Lorenzo Stoakes Cc: Mark Brown Cc: Paolo Abeni Cc: Ryan Roberts Cc: SeongJae Park Cc: Shuah Khan Cc: wang lian Cc: Yunsheng Lin Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/vm_util.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'tools/testing/selftests/mm/vm_util.h') diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 6ad32b1830f1..522f7f9050f5 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -54,6 +54,13 @@ static inline unsigned int pshift(void) return __page_shift; } +static inline void force_read_pages(char *addr, unsigned int nr_pages, + size_t pagesize) +{ + for (unsigned int i = 0; i < nr_pages; i++) + FORCE_READ(addr[i * pagesize]); +} + bool detect_huge_zeropage(void); /* -- cgit v1.2.3