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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: linux-mm@kvack.org, akpm@linux-foundation.org
Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
	Mike Rapoport <rppt@kernel.org>, Shuah Khan <shuah@kernel.org>,
	linux-kselftest@vger.kernel.org,
	Mike Rapoport <rppt@linux.ibm.com>,
	"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Subject: [PATCH v4 2/2] selftest/vm: add helpers to detect PAGE_SIZE and PAGE_SHIFT
Date: Mon,  7 Mar 2022 11:13:55 +0530	[thread overview]
Message-ID: <20220307054355.149820-2-aneesh.kumar@linux.ibm.com> (raw)
In-Reply-To: <20220307054355.149820-1-aneesh.kumar@linux.ibm.com>

From: Mike Rapoport <rppt@kernel.org>

PAGE_SIZE is not 4096 in many configurations, particularly ppc64 uses
64K pages in majority of cases.

Add helpers to detect PAGE_SIZE and PAGE_SHIFT dynamically.

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@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 tools/testing/selftests/vm/gup_test.c |  3 ++-
 tools/testing/selftests/vm/util.h     | 27 ++++++++++++++++++++++++---
 2 files changed, 26 insertions(+), 4 deletions(-)

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/util.h b/tools/testing/selftests/vm/util.h
index 0f0a0f345d76..b27d26199334 100644
--- a/tools/testing/selftests/vm/util.h
+++ b/tools/testing/selftests/vm/util.h
@@ -6,11 +6,32 @@
 #include <stdint.h>
 #include <sys/mman.h>
 #include <err.h>
+#include <string.h> /* ffsl() */
+#include <unistd.h> /* _SC_PAGESIZE */
 
-#define PAGE_SHIFT	12
-#define HPAGE_SHIFT	21
+static unsigned int __page_size;
+static unsigned int __page_shift;
 
-#define PAGE_SIZE (1 << PAGE_SHIFT)
+static inline unsigned int page_size(void)
+{
+	if (!__page_size)
+		__page_size = sysconf(_SC_PAGESIZE);
+	return __page_size;
+}
+
+static inline unsigned int 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())
+/*
+ * On ppc64 this will only work with radix 2M hugepage size
+ */
+#define HPAGE_SHIFT 21
 #define HPAGE_SIZE (1 << HPAGE_SHIFT)
 
 #define PAGEMAP_PRESENT(ent)	(((ent) & (1ull << 63)) != 0)
-- 
2.35.1


WARNING: multiple messages have this Message-ID (diff)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: linux-mm@kvack.org, akpm@linux-foundation.org
Cc: linuxppc-dev@lists.ozlabs.org, Mike Rapoport <rppt@linux.ibm.com>,
	linux-kselftest@vger.kernel.org,
	"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
	Shuah Khan <shuah@kernel.org>, Mike Rapoport <rppt@kernel.org>
Subject: [PATCH v4 2/2] selftest/vm: add helpers to detect PAGE_SIZE and PAGE_SHIFT
Date: Mon,  7 Mar 2022 11:13:55 +0530	[thread overview]
Message-ID: <20220307054355.149820-2-aneesh.kumar@linux.ibm.com> (raw)
In-Reply-To: <20220307054355.149820-1-aneesh.kumar@linux.ibm.com>

From: Mike Rapoport <rppt@kernel.org>

PAGE_SIZE is not 4096 in many configurations, particularly ppc64 uses
64K pages in majority of cases.

Add helpers to detect PAGE_SIZE and PAGE_SHIFT dynamically.

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@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 tools/testing/selftests/vm/gup_test.c |  3 ++-
 tools/testing/selftests/vm/util.h     | 27 ++++++++++++++++++++++++---
 2 files changed, 26 insertions(+), 4 deletions(-)

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/util.h b/tools/testing/selftests/vm/util.h
index 0f0a0f345d76..b27d26199334 100644
--- a/tools/testing/selftests/vm/util.h
+++ b/tools/testing/selftests/vm/util.h
@@ -6,11 +6,32 @@
 #include <stdint.h>
 #include <sys/mman.h>
 #include <err.h>
+#include <string.h> /* ffsl() */
+#include <unistd.h> /* _SC_PAGESIZE */
 
-#define PAGE_SHIFT	12
-#define HPAGE_SHIFT	21
+static unsigned int __page_size;
+static unsigned int __page_shift;
 
-#define PAGE_SIZE (1 << PAGE_SHIFT)
+static inline unsigned int page_size(void)
+{
+	if (!__page_size)
+		__page_size = sysconf(_SC_PAGESIZE);
+	return __page_size;
+}
+
+static inline unsigned int 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())
+/*
+ * On ppc64 this will only work with radix 2M hugepage size
+ */
+#define HPAGE_SHIFT 21
 #define HPAGE_SIZE (1 << HPAGE_SHIFT)
 
 #define PAGEMAP_PRESENT(ent)	(((ent) & (1ull << 63)) != 0)
-- 
2.35.1


  reply	other threads:[~2022-03-07  5:44 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-07  5:43 [PATCH v4 1/2] selftest/vm: Add util.h and and move helper functions there Aneesh Kumar K.V
2022-03-07  5:43 ` Aneesh Kumar K.V
2022-03-07  5:43 ` Aneesh Kumar K.V [this message]
2022-03-07  5:43   ` [PATCH v4 2/2] selftest/vm: add helpers to detect PAGE_SIZE and PAGE_SHIFT Aneesh Kumar K.V

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