[v9,14/21] x86: mm: Don't display pages which aren't present in debugfs

Commit Message

Steven Price July 22, 2019, 3:42 p.m. UTC

For the /sys/kernel/debug/page_tables/ files, rather than outputing a
mostly empty line when a block of memory isn't present just skip the
line. This keeps the output shorter and will help with a future change
switching to using the generic page walk code as we no longer care about
the 'level' that the page table holes are at.

Signed-off-by: Steven Price <[e-mail]>
---
 arch/x86/mm/dump_pagetables.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Patch

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index ab67822fd2f4..95728027dd3b 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -301,8 +301,8 @@  static void note_page(struct seq_file *m, struct pg_state *st,
 		/*
 		 * Now print the actual finished series
 		 */
-		if (!st->marker->max_lines ||
-		    st->lines < st->marker->max_lines) {
+		if ((cur & _PAGE_PRESENT) && (!st->marker->max_lines ||
+		    st->lines < st->marker->max_lines)) {
 			pt_dump_seq_printf(m, st->to_dmesg,
 					   "0x%0*lx-0x%0*lx   ",
 					   width, st->start_address,
@@ -318,7 +318,8 @@  static void note_page(struct seq_file *m, struct pg_state *st,
 			printk_prot(m, st->current_prot, st->level,
 				    st->to_dmesg);
 		}
-		st->lines++;
+		if (cur & _PAGE_PRESENT)
+			st->lines++;
 
 		/*
 		 * We print markers for special areas of address space,