[PATCH v2 0/5] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables

[PATCH v2 0/5] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables

[David Hildenbrand]

Excessive details on MADV_POPULATE_(READ|WRITE) can be found in patch #2.

v1 -> v2:
- "mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page
   tables"
-- Renamed patch/series to match what's happening -- prefault page tables
-- Clarified MADV_POPULATE_READ semantics on file holes and that we might
   want fallocate().
-- Updated/clarified description
-- Dropped -EINVAL and -EBUSY checks
-- Added a comment regarding FOLL_TOUCH and why we don't care that
   pages will get set dirty when triggering write-faults for now.
-- Reran and extended performance measurements by more fallocate()
   combinations

RFCv2 -> v1
- "mm: fix variable name in declaration of populate_vma_page_range()"
-- Added
- "mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault ..."
-- Fix detection of memory holes when we have to re-lookup the VMA
-- Return -EHWPOISON to user space when we hit HW poisoned pages
-- Make variable names in definition and declaration consistent
- "MAINTAINERS: add tools/testing/selftests/vm/ to MEMORY MANAGEMENT"
-- Added
- "selftests/vm: add protection_keys_32 / protection_keys_64 to gitignore"
-- Added
- "selftests/vm: add test for MADV_POPULATE_(READ|WRITE)"
-- Added

RFC -> RFCv2:
- Fix re-locking (-> set "locked = 1;")
- Don't mimic MAP_POPULATE semantics:
--> Explicit READ/WRITE request instead of selecting it automatically,
    which makes it more generic and better suited for some use cases (e.g., we
    usually want to prefault shmem writable)
--> Require proper access permissions
- Introduce and use faultin_vma_page_range()
--> Properly handle HWPOISON pages (FOLL_HWPOISON)
--> Require proper access permissions (!FOLL_FORCE)
- Let faultin_vma_page_range() check for compatible mappings/permissions
- Extend patch description and add some performance numbers


David Hildenbrand (5):
  mm: make variable names for populate_vma_page_range() consistent
  mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page
    tables
  MAINTAINERS: add tools/testing/selftests/vm/ to MEMORY MANAGEMENT
  selftests/vm: add protection_keys_32 / protection_keys_64 to gitignore
  selftests/vm: add test for MADV_POPULATE_(READ|WRITE)

 MAINTAINERS                                |   1 +
 arch/alpha/include/uapi/asm/mman.h         |   3 +
 arch/mips/include/uapi/asm/mman.h          |   3 +
 arch/parisc/include/uapi/asm/mman.h        |   3 +
 arch/xtensa/include/uapi/asm/mman.h        |   3 +
 include/uapi/asm-generic/mman-common.h     |   3 +
 mm/gup.c                                   |  58 ++++
 mm/internal.h                              |   5 +-
 mm/madvise.c                               |  66 ++++
 tools/testing/selftests/vm/.gitignore      |   3 +
 tools/testing/selftests/vm/Makefile        |   1 +
 tools/testing/selftests/vm/madv_populate.c | 342 +++++++++++++++++++++
 tools/testing/selftests/vm/run_vmtests.sh  |  16 +
 13 files changed, 506 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/vm/madv_populate.c

-- 
2.30.2

[PATCH v2 1/5] mm: make variable names for populate_vma_page_range() consistent

[David Hildenbrand]

Let's make the variable names in the function declaration match the
variable names used in the definition.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/internal.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/internal.h b/mm/internal.h
index cb3c5e0a7799..bbf1c1274983 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -354,7 +354,7 @@ void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
 
 #ifdef CONFIG_MMU
 extern long populate_vma_page_range(struct vm_area_struct *vma,
-		unsigned long start, unsigned long end, int *nonblocking);
+		unsigned long start, unsigned long end, int *locked);
 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
 			unsigned long start, unsigned long end);
 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
-- 
2.30.2

[PATCH v2 3/5] MAINTAINERS: add tools/testing/selftests/vm/ to MEMORY MANAGEMENT

[David Hildenbrand]

MEMORY MANAGEMENT seems to be a good fit.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 9450e052f1b1..cd267d218e08 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11566,6 +11566,7 @@ F:	include/linux/mm.h
 F:	include/linux/mmzone.h
 F:	include/linux/vmalloc.h
 F:	mm/
+F:	tools/testing/selftests/vm/
 
 MEMORY TECHNOLOGY DEVICES (MTD)
 M:	Miquel Raynal <miquel.raynal@bootlin.com>
-- 
2.30.2

[PATCH v2 4/5] selftests/vm: add protection_keys_32 / protection_keys_64 to gitignore

[David Hildenbrand]

We missed to add two binaries to gitignore.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 tools/testing/selftests/vm/.gitignore | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore
index 9a35c3f6a557..b4fc0148360e 100644
--- a/tools/testing/selftests/vm/.gitignore
+++ b/tools/testing/selftests/vm/.gitignore
@@ -22,3 +22,5 @@ map_fixed_noreplace
 write_to_hugetlbfs
 hmm-tests
 local_config.*
+protection_keys_32
+protection_keys_64
-- 
2.30.2

[PATCH v2 5/5] selftests/vm: add test for MADV_POPULATE_(READ|WRITE)

[David Hildenbrand]

Let's add a simple test for MADV_POPULATE_READ and MADV_POPULATE_WRITE,
verifying some error handling, that population works, and that softdirty
tracking works as expected. For now, limit the test to private anonymous
memory.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: Linux API <linux-api@vger.kernel.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 tools/testing/selftests/vm/.gitignore      |   1 +
 tools/testing/selftests/vm/Makefile        |   1 +
 tools/testing/selftests/vm/madv_populate.c | 342 +++++++++++++++++++++
 tools/testing/selftests/vm/run_vmtests.sh  |  16 +
 4 files changed, 360 insertions(+)
 create mode 100644 tools/testing/selftests/vm/madv_populate.c

diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore
index b4fc0148360e..c9a5dd1adf7d 100644
--- a/tools/testing/selftests/vm/.gitignore
+++ b/tools/testing/selftests/vm/.gitignore
@@ -24,3 +24,4 @@ hmm-tests
 local_config.*
 protection_keys_32
 protection_keys_64
+madv_populate
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index 8b0cd421ebd3..04b6650c1924 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -42,6 +42,7 @@ TEST_GEN_FILES += on-fault-limit
 TEST_GEN_FILES += thuge-gen
 TEST_GEN_FILES += transhuge-stress
 TEST_GEN_FILES += userfaultfd
+TEST_GEN_FILES += madv_populate
 
 ifeq ($(MACHINE),x86_64)
 CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_32bit_program.c -m32)
diff --git a/tools/testing/selftests/vm/madv_populate.c b/tools/testing/selftests/vm/madv_populate.c
new file mode 100644
index 000000000000..b959e4ebdad4
--- /dev/null
+++ b/tools/testing/selftests/vm/madv_populate.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MADV_POPULATE_READ and MADV_POPULATE_WRITE tests
+ *
+ * Copyright 2021, Red Hat, Inc.
+ *
+ * Author(s): David Hildenbrand <david@redhat.com>
+ */
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include "../kselftest.h"
+
+#if defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE)
+
+/*
+ * For now, we're using 2 MiB of private anonymous memory for all tests.
+ */
+#define SIZE (2 * 1024 * 1024)
+
+static size_t pagesize;
+
+static uint64_t pagemap_get_entry(int fd, char *start)
+{
+	const unsigned long pfn = (unsigned long)start / pagesize;
+	uint64_t entry;
+	int ret;
+
+	ret = pread(fd, &entry, sizeof(entry), pfn * sizeof(entry));
+	if (ret != sizeof(entry))
+		ksft_exit_fail_msg("reading pagemap failed\n");
+	return entry;
+}
+
+static bool pagemap_is_populated(int fd, char *start)
+{
+	uint64_t entry = pagemap_get_entry(fd, start);
+
+	/* Present or swapped. */
+	return entry & 0xc000000000000000ull;
+}
+
+static bool pagemap_is_softdirty(int fd, char *start)
+{
+	uint64_t entry = pagemap_get_entry(fd, start);
+
+	return entry & 0x0080000000000000ull;
+}
+
+static void sense_support(void)
+{
+	char *addr;
+	int ret;
+
+	addr = mmap(0, pagesize, PROT_READ | PROT_WRITE,
+		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (!addr)
+		ksft_exit_fail_msg("mmap failed\n");
+
+	ret = madvise(addr, pagesize, MADV_POPULATE_READ);
+	if (ret)
+		ksft_exit_skip("MADV_POPULATE_READ is not available\n");
+
+	ret = madvise(addr, pagesize, MADV_POPULATE_WRITE);
+	if (ret)
+		ksft_exit_skip("MADV_POPULATE_WRITE is not available\n");
+
+	munmap(addr, pagesize);
+}
+
+static void test_prot_read(void)
+{
+	char *addr;
+	int ret;
+
+	ksft_print_msg("[RUN] %s\n", __func__);
+
+	addr = mmap(0, SIZE, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap failed\n");
+
+	ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+	ksft_test_result(!ret, "MADV_POPULATE_READ with PROT_READ\n");
+
+	ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+	ksft_test_result(ret == -1 && errno == EINVAL,
+			 "MADV_POPULATE_WRITE with PROT_READ\n");
+
+	munmap(addr, SIZE);
+}
+
+static void test_prot_write(void)
+{
+	char *addr;
+	int ret;
+
+	ksft_print_msg("[RUN] %s\n", __func__);
+
+	addr = mmap(0, SIZE, PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap failed\n");
+
+	ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+	ksft_test_result(ret == -1 && errno == EINVAL,
+			 "MADV_POPULATE_READ with PROT_WRITE\n");
+
+	ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+	ksft_test_result(!ret, "MADV_POPULATE_WRITE with PROT_WRITE\n");
+
+	munmap(addr, SIZE);
+}
+
+static void test_holes(void)
+{
+	char *addr;
+	int ret;
+
+	ksft_print_msg("[RUN] %s\n", __func__);
+
+	addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap failed\n");
+	ret = munmap(addr + pagesize, pagesize);
+	if (ret)
+		ksft_exit_fail_msg("munmap failed\n");
+
+	/* Hole in the middle */
+	ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+	ksft_test_result(ret == -1 && errno == ENOMEM,
+			 "MADV_POPULATE_READ with holes in the middle\n");
+	ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+	ksft_test_result(ret == -1 && errno == ENOMEM,
+			 "MADV_POPULATE_WRITE with holes in the middle\n");
+
+	/* Hole at end */
+	ret = madvise(addr, 2 * pagesize, MADV_POPULATE_READ);
+	ksft_test_result(ret == -1 && errno == ENOMEM,
+			 "MADV_POPULATE_READ with holes at the end\n");
+	ret = madvise(addr, 2 * pagesize, MADV_POPULATE_WRITE);
+	ksft_test_result(ret == -1 && errno == ENOMEM,
+			 "MADV_POPULATE_WRITE with holes at the end\n");
+
+	/* Hole at beginning */
+	ret = madvise(addr + pagesize, pagesize, MADV_POPULATE_READ);
+	ksft_test_result(ret == -1 && errno == ENOMEM,
+			 "MADV_POPULATE_READ with holes at the beginning\n");
+	ret = madvise(addr + pagesize, pagesize, MADV_POPULATE_WRITE);
+	ksft_test_result(ret == -1 && errno == ENOMEM,
+			 "MADV_POPULATE_WRITE with holes at the beginning\n");
+
+	munmap(addr, SIZE);
+}
+
+static bool range_is_populated(char *start, ssize_t size)
+{
+	int fd = open("/proc/self/pagemap", O_RDONLY);
+	bool ret = true;
+
+	if (fd < 0)
+		ksft_exit_fail_msg("opening pagemap failed\n");
+	for (; size > 0 && ret; size -= pagesize, start += pagesize)
+		if (!pagemap_is_populated(fd, start))
+			ret = false;
+	close(fd);
+	return ret;
+}
+
+static bool range_is_not_populated(char *start, ssize_t size)
+{
+	int fd = open("/proc/self/pagemap", O_RDONLY);
+	bool ret = true;
+
+	if (fd < 0)
+		ksft_exit_fail_msg("opening pagemap failed\n");
+	for (; size > 0 && ret; size -= pagesize, start += pagesize)
+		if (pagemap_is_populated(fd, start))
+			ret = false;
+	close(fd);
+	return ret;
+}
+
+static void test_populate_read(void)
+{
+	char *addr;
+	int ret;
+
+	ksft_print_msg("[RUN] %s\n", __func__);
+
+	addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap failed\n");
+	ksft_test_result(range_is_not_populated(addr, SIZE),
+			 "range initially not populated\n");
+
+	ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+	ksft_test_result(!ret, "MADV_POPULATE_READ\n");
+	ksft_test_result(range_is_populated(addr, SIZE),
+			 "range is populated\n");
+
+	munmap(addr, SIZE);
+}
+
+static void test_populate_write(void)
+{
+	char *addr;
+	int ret;
+
+	ksft_print_msg("[RUN] %s\n", __func__);
+
+	addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap failed\n");
+	ksft_test_result(range_is_not_populated(addr, SIZE),
+			 "range initially not populated\n");
+
+	ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+	ksft_test_result(!ret, "MADV_POPULATE_WRITE\n");
+	ksft_test_result(range_is_populated(addr, SIZE),
+			 "range is populated\n");
+
+	munmap(addr, SIZE);
+}
+
+static bool range_is_softdirty(char *start, ssize_t size)
+{
+	int fd = open("/proc/self/pagemap", O_RDONLY);
+	bool ret = true;
+
+	if (fd < 0)
+		ksft_exit_fail_msg("opening pagemap failed\n");
+	for (; size > 0 && ret; size -= pagesize, start += pagesize)
+		if (!pagemap_is_softdirty(fd, start))
+			ret = false;
+	close(fd);
+	return ret;
+}
+
+static bool range_is_not_softdirty(char *start, ssize_t size)
+{
+	int fd = open("/proc/self/pagemap", O_RDONLY);
+	bool ret = true;
+
+	if (fd < 0)
+		ksft_exit_fail_msg("opening pagemap failed\n");
+	for (; size > 0 && ret; size -= pagesize, start += pagesize)
+		if (pagemap_is_softdirty(fd, start))
+			ret = false;
+	close(fd);
+	return ret;
+}
+
+static void clear_softdirty(void)
+{
+	int fd = open("/proc/self/clear_refs", O_WRONLY);
+	const char *ctrl = "4";
+	int ret;
+
+	if (fd < 0)
+		ksft_exit_fail_msg("opening clear_refs failed\n");
+	ret = write(fd, ctrl, strlen(ctrl));
+	if (ret != strlen(ctrl))
+		ksft_exit_fail_msg("writing clear_refs failed\n");
+	close(fd);
+}
+
+static void test_softdirty(void)
+{
+	char *addr;
+	int ret;
+
+	ksft_print_msg("[RUN] %s\n", __func__);
+
+	addr = mmap(0, SIZE, PROT_READ | PROT_WRITE,
+		    MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap failed\n");
+
+	/* Clear any softdirty bits. */
+	clear_softdirty();
+	ksft_test_result(range_is_not_softdirty(addr, SIZE),
+			 "range is not softdirty\n");
+
+	/* Populating READ should set softdirty. */
+	ret = madvise(addr, SIZE, MADV_POPULATE_READ);
+	ksft_test_result(!ret, "MADV_POPULATE_READ\n");
+	ksft_test_result(range_is_not_softdirty(addr, SIZE),
+			 "range is not softdirty\n");
+
+	/* Populating WRITE should set softdirty. */
+	ret = madvise(addr, SIZE, MADV_POPULATE_WRITE);
+	ksft_test_result(!ret, "MADV_POPULATE_WRITE\n");
+	ksft_test_result(range_is_softdirty(addr, SIZE),
+			 "range is softdirty\n");
+
+	munmap(addr, SIZE);
+}
+
+int main(int argc, char **argv)
+{
+	int err;
+
+	pagesize = getpagesize();
+
+	ksft_print_header();
+	ksft_set_plan(21);
+
+	sense_support();
+	test_prot_read();
+	test_prot_write();
+	test_holes();
+	test_populate_read();
+	test_populate_write();
+	test_softdirty();
+
+	err = ksft_get_fail_cnt();
+	if (err)
+		ksft_exit_fail_msg("%d out of %d tests failed\n",
+				   err, ksft_test_num());
+	return ksft_exit_pass();
+}
+
+#else /* defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE) */
+
+#warning "missing MADV_POPULATE_READ or MADV_POPULATE_WRITE definition"
+
+int main(int argc, char **argv)
+{
+	ksft_print_header();
+	ksft_exit_skip("MADV_POPULATE_READ or MADV_POPULATE_WRITE not defined\n");
+}
+
+#endif /* defined(MADV_POPULATE_READ) && defined(MADV_POPULATE_WRITE) */
diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh
index e953f3cd9664..955782d138ab 100755
--- a/tools/testing/selftests/vm/run_vmtests.sh
+++ b/tools/testing/selftests/vm/run_vmtests.sh
@@ -346,4 +346,20 @@ else
 	exitcode=1
 fi
 
+echo "--------------------------------------------------------"
+echo "running MADV_POPULATE_READ and MADV_POPULATE_WRITE tests"
+echo "--------------------------------------------------------"
+./madv_populate
+ret_val=$?
+
+if [ $ret_val -eq 0 ]; then
+	echo "[PASS]"
+elif [ $ret_val -eq $ksft_skip ]; then
+	echo "[SKIP]"
+	exitcode=$ksft_skip
+else
+	echo "[FAIL]"
+	exitcode=1
+fi
+
 exit $exitcode
-- 
2.30.2

Re: [PATCH v2 0/5] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables

[Andrew Morton]

On Mon, 19 Apr 2021 15:54:38 +0200 David Hildenbrand <david@redhat.com> wrote:

> Excessive details on MADV_POPULATE_(READ|WRITE) can be found in patch #2.

I grabbed the series, but some additional review would help things
along here..

Did patch #2 actually make it to linux-mm?  It's missing from my
archive. 
https://lkml.kernel.org/r/20210419135443.12822-3-david@redhat.com lands
on the linux-api@vger copy.

Re: [PATCH v2 0/5] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables

[David Hildenbrand]

On 10.05.21 06:21, Andrew Morton wrote:
> On Mon, 19 Apr 2021 15:54:38 +0200 David Hildenbrand <david@redhat.com> wrote:
> 
>> Excessive details on MADV_POPULATE_(READ|WRITE) can be found in patch #2.
> 
> I grabbed the series, but some additional review would help things
> along here..

Thanks -- indeed, while there have been some comments to previous 
versions that improved the series as a whole, there are no explicit acks 
or rbs. Fortunately, we still have some time until the next merge window 
opens :)

> 
> Did patch #2 actually make it to linux-mm?  It's missing from my
> archive.

Ehm, good point. I punch out everything via " git send-email  --to 
linux-kernel@vger.kernel.org  --cc "linux-mm@kvack.org" ..." and don't 
remember any bounces.

Doesn't seem to appear on linux-mm:

https://lore.kernel.org/linux-mm/20210419135443.12822-1-david@redhat.com/

But it did make it to lkml as well:

https://lore.kernel.org/lkml/20210419135443.12822-3-david@redhat.com/

> https://lkml.kernel.org/r/20210419135443.12822-3-david@redhat.com lands
> on the linux-api@vger copy.

Weird, looks like linux-mm is swallowing mails.

I can just resend the series, thoughts?

-- 
Thanks,

David / dhildenb

Re: [PATCH v2 0/5] mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables

[Andrew Morton]

On Mon, 10 May 2021 16:52:33 +0200 David Hildenbrand <david@redhat.com> wrote:

> I can just resend the series, thoughts?

Sure, that makes it easier on folks.