[PATCH] mm: remove VM_EXEC requirement for THP eligibility

From: Fangrui Song
Date: Wed Dec 20 2023 - 00:41:36 EST


Commit e6be37b2e7bd ("mm/huge_memory.c: add missing read-only THP
checking in transparent_hugepage_enabled()") introduced the VM_EXEC
requirement, which is not strictly needed.

lld's default --rosegment option and GNU ld's -z separate-code option
(default on Linux/x86 since binutils 2.31) create a read-only PT_LOAD
segment without the PF_X flag, which should be eligible for THP.

Certain architectures support medium and large code models, where
.lrodata may be placed in a separate read-only PT_LOAD segment, which
should be eligible for THP as well.

Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx>
---
include/linux/huge_mm.h | 1 -
1 file changed, 1 deletion(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index fa0350b0812a..4c9e67e9000f 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -126,7 +126,6 @@ static inline bool file_thp_enabled(struct vm_area_struct *vma)
inode = vma->vm_file->f_inode;

return (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS)) &&
- (vma->vm_flags & VM_EXEC) &&
!inode_is_open_for_write(inode) && S_ISREG(inode->i_mode);
}

--
2.43.0.472.g3155946c3a-goog