[PATCH v4 15/20] powerpc/mm: Avoid useless lock with single page fragments
From: Christophe Leroy <hidden>
Date: 2018-09-18 16:57:37
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
There is no point in taking the page table lock as pte_frag is always NULL when we have only one fragment. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/mm/pgtable-frag.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
index bc924822dcd6..ab4910e92aaf 100644
--- a/arch/powerpc/mm/pgtable-frag.c
+++ b/arch/powerpc/mm/pgtable-frag.c@@ -85,6 +85,9 @@ static pte_t *get_pte_from_cache(struct mm_struct *mm) { void *pte_frag, *ret; + if (PTE_FRAG_NR == 1) + return NULL; + spin_lock(&mm->page_table_lock); ret = mm->context.pte_frag; if (ret) {
--
2.13.3