From 2364c963c65c7f3640ef515dfb2046b78bc9a975 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= <emmir@google.com>
Date: Fri, 2 Jun 2023 17:22:06 +0200
Subject: [PATCH] Log if prctl(SET_THP_DISABLE) doesn't work as expected.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

If prctl(SET_THP_DISABLE) is not used due to bad semantics, log it
for easier debugging.

Signed-off-by: Michał Mirosław <emmir@google.com>
---
 criu/kerndat.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/criu/kerndat.c b/criu/kerndat.c
index bc0c7ba05..d38e8898e 100644
--- a/criu/kerndat.c
+++ b/criu/kerndat.c
@@ -1324,6 +1324,8 @@ int kerndat_has_thp_disable(void)
 
 			parse_vmflags(str, &flags, &madv, &io_pf);
 			kdat.has_thp_disable = !(madv & (1 << MADV_NOHUGEPAGE));
+			if (!kdat.has_thp_disable)
+				pr_warn("prctl PR_SET_THP_DISABLE sets MADV_NOHUGEPAGE");
 			break;
 		}
 	}