On 25.10.22 17:26, Gerald Schaefer wrote:
hugepage-vmemmap test fails for s390 because it assumes a hugepagesize
of 2 MB, while we have 1 MB on s390. This results in iterating over two
hugepages. If they are consecutive in memory, check_page_flags() will
stumble over the additional head page. Otherwise, it will stumble over
non-huge pageflags, after crossing the first 1 MB hugepage.
Fix this by using 1 MB MAP_LENGTH for s390.
Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
---
tools/testing/selftests/vm/hugepage-vmemmap.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/tools/testing/selftests/vm/hugepage-vmemmap.c b/tools/testing/selftests/vm/hugepage-vmemmap.c
index 557bdbd4f87e..a4695f138cec 100644
--- a/tools/testing/selftests/vm/hugepage-vmemmap.c
+++ b/tools/testing/selftests/vm/hugepage-vmemmap.c
@@ -11,7 +11,14 @@
#include <sys/mman.h>
#include <fcntl.h>
+/*
+ * 1 MB hugepage size for s390
+ */
+#if defined(__s390x__)
+#define MAP_LENGTH (1UL * 1024 * 1024)
+#else
#define MAP_LENGTH (2UL * 1024 * 1024)
+#endif
Why not detect it at runtime, so this works on any architecture (e.g.,
ppc64 with 16 MiB IIRC and arm64 with weird sizes)?
A patch that adds such detection code is currently on its way upstream:
https://lore.kernel.org/all/20220927110120.106906-5-david@xxxxxxxxxx/T/#u
We could factor that out into vm_utils.c
--
Thanks,
David / dhildenb
