From 0ba09b1733878afe838fe35c310715fda3d46428 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 4 Dec 2022 12:51:59 -0800 Subject: Revert "mm: align larger anonymous mappings on THP boundaries" This reverts commit f35b5d7d676e59e401690b678cd3cfec5e785c23. It has been reported to cause huge performance regressions on some loads (will-it-scale.per_process_ops, but also building the kernel with clang). The commit did speed up gcc builds by a small amount, so it's not an unambiguous regression, but until the big regressions are understood, let's revert it. Reported-by: kernel test robot Link: https://lore.kernel.org/r/202210181535.7144dd15-yujie.liu@intel.com Reported-by: Nathan Chancellor Link: https://lore.kernel.org/lkml/Y1DNQaoPWxE%2BrGce@dev-arch.thelio-3990X/ Cc: Huang, Ying Cc: Rik van Riel Cc: Andrew Morton Cc: Yang Shi Signed-off-by: Linus Torvalds --- mm/mmap.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 74a84eb33b90..a5eb2f175da0 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1779,9 +1779,6 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, */ pgoff = 0; get_area = shmem_get_unmapped_area; - } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { - /* Ensures that larger anonymous mappings are THP aligned. */ - get_area = thp_get_unmapped_area; } addr = get_area(file, addr, len, pgoff, flags); -- cgit v1.2.3