From f385cb85a42fc4ba92464c2bfd2e2049d65353d3 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 23 Sep 2019 15:38:33 -0700 Subject: uprobe: collapse THP pmd after removing all uprobes After all uprobes are removed from the huge page (with PTE pgtable), it is possible to collapse the pmd and benefit from THP again. This patch does the collapse by calling collapse_pte_mapped_thp(). Link: http://lkml.kernel.org/r/20190815164525.1848545-7-songliubraving@fb.com Signed-off-by: Song Liu Acked-by: Kirill A. Shutemov Reported-by: kbuild test robot Reviewed-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/events/uprobes.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel') diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 27b596f14463..94d38a39d72e 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -26,6 +26,7 @@ #include #include #include +#include #include @@ -472,6 +473,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, struct page *old_page, *new_page; struct vm_area_struct *vma; int ret, is_register, ref_ctr_updated = 0; + bool orig_page_huge = false; is_register = is_swbp_insn(&opcode); uprobe = container_of(auprobe, struct uprobe, arch); @@ -529,6 +531,9 @@ retry: /* let go new_page */ put_page(new_page); new_page = NULL; + + if (PageCompound(orig_page)) + orig_page_huge = true; } put_page(orig_page); } @@ -547,6 +552,10 @@ put_old: if (ret && is_register && ref_ctr_updated) update_ref_ctr(uprobe, mm, -1); + /* try collapse pmd for compound page */ + if (!ret && orig_page_huge) + collapse_pte_mapped_thp(mm, vaddr); + return ret; } -- cgit v1.2.3