Hi Aneesh,
On Fri, Feb 11, 2022 at 05:22:13PM +0530, Aneesh Kumar K V wrote:
On 2/11/22 16:03, Mike Rapoport wrote:
On Fri, Feb 11, 2022 at 12:03:28PM +0530, Aneesh Kumar K.V wrote:
Keep it simple by using a #define and limiting hugepage size to 2M.
This keeps the test simpler instead of dynamically finding the page size
and huge page size.
Without this tests are broken w.r.t reading /proc/self/pagemap
if (pread(pagemap_fd, ent, sizeof(ent),
(uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
err(2, "read pagemap");
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
tools/testing/selftests/vm/ksm_tests.c | 9 ++++++++-
tools/testing/selftests/vm/transhuge-stress.c | 9 ++++++++-
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c
index 1436e1a9a3d3..cae72872152b 100644
--- a/tools/testing/selftests/vm/ksm_tests.c
+++ b/tools/testing/selftests/vm/ksm_tests.c
@@ -22,7 +22,14 @@
#define KSM_MERGE_ACROSS_NODES_DEFAULT true
#define MB (1ul << 20)
-#define PAGE_SHIFT 12
+#ifdef __powerpc64__
+#define PAGE_SHIFT 16
+#else
+#define PAGE_SHIFT 12
+#endif
Page size can be other than 4096 for other configurations as well. And even
on ppc64 it's not necessarily 64k.
But most common test config is with 64K page size.
Ideally page size in selftests/vm should be sysconf(_SC_PAGESIZE)
yes. As explained in commit message, the idea was to keep it simpler.
I think it's simple enough (compile tested on x86 only):
From 219577d87041f19f2c00dc7c23e0fd5aad8b02d5 Mon Sep 17 00:00:00 2001
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Date: Fri, 11 Feb 2022 15:24:13 +0200
Subject: [PATCH] selftest/vm: add helpers to detect PAGE_SIZE and PAGE_SHIFT
PAGE_SIZE is not 4096 in many configurations, particularily ppc64 uses
64K pages in majority of cases.
Add helpers to detect PAGE_SIZE and PAGE_SHIFT dynamically.
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
tools/testing/selftests/vm/gup_test.c | 3 +-
tools/testing/selftests/vm/ksm_tests.c | 8 +----
tools/testing/selftests/vm/transhuge-stress.c | 9 ++----
tools/testing/selftests/vm/util.h | 29 +++++++++++++++++++
4 files changed, 34 insertions(+), 15 deletions(-)
create mode 100644 tools/testing/selftests/vm/util.h
diff --git a/tools/testing/selftests/vm/gup_test.c b/tools/testing/selftests/vm/gup_test.c
index fe043f67798b..cda837a14736 100644
--- a/tools/testing/selftests/vm/gup_test.c
+++ b/tools/testing/selftests/vm/gup_test.c
@@ -10,8 +10,9 @@
#include <assert.h>
#include "../../../../mm/gup_test.h"
+#include "util.h"
+
#define MB (1UL << 20)
-#define PAGE_SIZE sysconf(_SC_PAGESIZE)
/* Just the flags we need, copied from mm.h: */
#define FOLL_WRITE 0x01 /* check pte is writable */
diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c
index cae72872152b..7faafd24446f 100644
--- a/tools/testing/selftests/vm/ksm_tests.c
+++ b/tools/testing/selftests/vm/ksm_tests.c
@@ -12,6 +12,7 @@
#include "../kselftest.h"
#include "../../../../include/vdso/time64.h"
+#include "util.h"
#define KSM_SYSFS_PATH "/sys/kernel/mm/ksm/"
#define KSM_FP(s) (KSM_SYSFS_PATH s)
@@ -22,17 +23,10 @@
#define KSM_MERGE_ACROSS_NODES_DEFAULT true
#define MB (1ul << 20)
-#ifdef __powerpc64__
-#define PAGE_SHIFT 16
-#else
-#define PAGE_SHIFT 12
-#endif
/*
* On ppc64 this will only work with radix 2M hugepage size
*/
#define HPAGE_SHIFT 21
-
-#define PAGE_SIZE (1 << PAGE_SHIFT)
#define HPAGE_SIZE (1 << HPAGE_SHIFT)
#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
diff --git a/tools/testing/selftests/vm/transhuge-stress.c b/tools/testing/selftests/vm/transhuge-stress.c
index b1f8d98355c5..baf90a745d28 100644
--- a/tools/testing/selftests/vm/transhuge-stress.c
+++ b/tools/testing/selftests/vm/transhuge-stress.c
@@ -16,17 +16,12 @@
#include <string.h>
#include <sys/mman.h>
-#ifdef __powerpc64__
-#define PAGE_SHIFT 16
-#else
-#define PAGE_SHIFT 12
-#endif
+#include "util.h"
+
/*
* On ppc64 this will only work with radix 2M hugepage size
*/
#define HPAGE_SHIFT 21
-
-#define PAGE_SIZE (1 << PAGE_SHIFT)
#define HPAGE_SIZE (1 << HPAGE_SHIFT)
#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
diff --git a/tools/testing/selftests/vm/util.h b/tools/testing/selftests/vm/util.h
new file mode 100644
index 000000000000..1c85d7583bac
--- /dev/null
+++ b/tools/testing/selftests/vm/util.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __KSELFTEST_VM_UTIL_H
+#define __KSELFTEST_VM_UTIL_H
+
+#include <string.h> /* ffsl() */
+#include <unistd.h> /* _SC_PAGESIZE */
+
+static unsigned __page_size;
+static unsigned __page_shift;
+
+static inline unsigned page_size(void)
+{
+ if (!__page_size)
+ __page_size = sysconf(_SC_PAGESIZE);
+ return __page_size;
+}
+
+static inline unsigned page_shift(void)
+{
+ if (!__page_shift)
+ __page_shift = (ffsl(page_size()) - 1);
+ return __page_shift;
+}
+
+#define PAGE_SHIFT (page_shift())
+#define PAGE_SIZE (page_size())
+
+#endif /* __KSELFTEST_VM_UTIL_H */
