[PATCH v2 1/6] kselftests: vm: Add mremap tests
Test mremap on regions of various sizes and alignments and validate
data after remapping. Also provide total time for remapping
the region which is useful for performance comparison of the mremap
optimizations that move pages at the PMD/PUD levels if HAVE_MOVE_PMD
and/or HAVE_MOVE_PUD are enabled.
Signed-off-by: Kalesh Singh
---
Changes in v2:
- Reduce test time by only validating a certain threshold of the
remapped region (4MB by default). The -t flag can be used to
set a custom threshold in MB or no threshold by passing 0. (-t0).
mremap time is not provided in stdout for only partially validated
regions. This time is only applicable for comparison if the entire
mapped region was faulted in.
- Use a random pattern for validating the remapped region. The -p
flag can be used to run the tests with a specified seed for the
random pattern.
- Print test configs (threshold_mb and pattern_seed) to stdout.
- Remove MAKE_SIMPLE_TEST macro.
- Define named flags instead of 0 / 1.
- Add comments for destination address' align_mask and offset.
tools/testing/selftests/vm/.gitignore| 1 +
tools/testing/selftests/vm/Makefile | 1 +
tools/testing/selftests/vm/mremap_test.c | 333 +++
tools/testing/selftests/vm/run_vmtests | 11 +
4 files changed, 346 insertions(+)
create mode 100644 tools/testing/selftests/vm/mremap_test.c
diff --git a/tools/testing/selftests/vm/.gitignore
b/tools/testing/selftests/vm/.gitignore
index 849e8226395a..b3a183c36cb5 100644
--- a/tools/testing/selftests/vm/.gitignore
+++ b/tools/testing/selftests/vm/.gitignore
@@ -8,6 +8,7 @@ thuge-gen
compaction_test
mlock2-tests
mremap_dontunmap
+mremap_test
on-fault-limit
transhuge-stress
protection_keys
diff --git a/tools/testing/selftests/vm/Makefile
b/tools/testing/selftests/vm/Makefile
index a9026706d597..f044808b45fa 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -16,6 +16,7 @@ TEST_GEN_FILES += map_populate
TEST_GEN_FILES += mlock-random-test
TEST_GEN_FILES += mlock2-tests
TEST_GEN_FILES += mremap_dontunmap
+TEST_GEN_FILES += mremap_test
TEST_GEN_FILES += on-fault-limit
TEST_GEN_FILES += thuge-gen
TEST_GEN_FILES += transhuge-stress
diff --git a/tools/testing/selftests/vm/mremap_test.c
b/tools/testing/selftests/vm/mremap_test.c
new file mode 100644
index ..abe1f0a5a26a
--- /dev/null
+++ b/tools/testing/selftests/vm/mremap_test.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Google LLC
+ */
+#define _GNU_SOURCE
+
+#include
+#include
+#include
+#include
+#include
+
+#include "../kselftest.h"
+
+#define EXPECT_SUCCESS 0
+#define EXPECT_FAILURE 1
+#define NON_OVERLAPPING 0
+#define OVERLAPPING 1
+#define NS_PER_SEC 10ULL
+#define VALIDATION_DEFAULT_THRESHOLD 4 /* 4MB */
+#define VALIDATION_NO_THRESHOLD 0 /* Verify the entire region */
+#define PATTERN_SIZE 3
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+
+struct config {
+ unsigned long long src_alignment;
+ unsigned long long dest_alignment;
+ unsigned long long region_size;
+ int overlapping;
+};
+
+struct test {
+ const char *name;
+ struct config config;
+ int expect_failure;
+};
+
+enum {
+ _1KB = 1ULL << 10, /* 1KB -> not page aligned */
+ _4KB = 4ULL << 10,
+ _8KB = 8ULL << 10,
+ _1MB = 1ULL << 20,
+ _2MB = 2ULL << 20,
+ _4MB = 4ULL << 20,
+ _1GB = 1ULL << 30,
+ _2GB = 2ULL << 30,
+ PTE = _4KB,
+ PMD = _2MB,
+ PUD = _1GB,
+};
+
+#define MAKE_TEST(source_align, destination_align, size, \
+ overlaps, should_fail, test_name) \
+{ \
+ .name = test_name, \
+ .config = { \
+ .src_alignment = source_align, \
+ .dest_alignment = destination_align,\
+ .region_size = size,\
+ .overlapping = overlaps,\
+ }, \
+ .expect_failure = should_fail \
+}
+
+/*
+ * Returns the start address of the mapping on success, else returns
+ * NULL on failure.
+ */
+static void *get_source_mapping(struct config c)
+{
+ unsigned long long addr = 0ULL;
+ void *src_addr = NULL;
+retry:
+ addr += c.src_alignment;
+ src_addr = mmap((void *) addr, c.region_size, PROT_READ | PROT_WRITE,
+ MAP_FIXED | MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+ if (src_addr == MAP_FAILED) {
+ if (errno == EPERM)
+ goto retry;
+ goto error;
+ }
+ /*
+* Check that the addr
Re: [PATCH v2 1/6] kselftests: vm: Add mremap tests
On Sat, Oct 3, 2020 at 3:13 AM John Hubbard wrote:
>
> On 10/2/20 9:20 AM, Kalesh Singh wrote:
> > Test mremap on regions of various sizes and alignments and validate
> > data after remapping. Also provide total time for remapping
> > the region which is useful for performance comparison of the mremap
> > optimizations that move pages at the PMD/PUD levels if HAVE_MOVE_PMD
> > and/or HAVE_MOVE_PUD are enabled.
> >
> > Signed-off-by: Kalesh Singh
> > ---
> > Changes in v2:
> >- Reduce test time by only validating a certain threshold of the
> > remapped region (4MB by default). The -t flag can be used to
> > set a custom threshold in MB or no threshold by passing 0. (-t0).
> > mremap time is not provided in stdout for only partially validated
> > regions. This time is only applicable for comparison if the entire
> > mapped region was faulted in.
> >- Use a random pattern for validating the remapped region. The -p
> > flag can be used to run the tests with a specified seed for the
> > random pattern.
> >- Print test configs (threshold_mb and pattern_seed) to stdout.
> >- Remove MAKE_SIMPLE_TEST macro.
> >- Define named flags instead of 0 / 1.
> >- Add comments for destination address' align_mask and offset.
>
> Thanks for making those changes. This all looks much nicer, both in the
> code and on the screen. Now it's easy to see which code generates which
> output, and the tests are readable. The new comments are also helpful.
>
> I ran it locally and it came in at 0.6 sec, so that looks good.
>
> A remaining nit: there are lots of > 80 col lines here. Only those lines
> that contain printf output strings really need to be extra-long. The
> others can all be easily made to fit.
Thanks for the review John. I can fix the lines that don't need to be
>80 col. FWIW checkpatch now allows 100 col lines:
https://lore.kernel.org/r/9c360bfa43580ce7726dd3d9d247f1216a690ef0.ca...@perches.com
>
> ...
> > +
> > +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
> > +#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
>
>
> Not really a comment on this patch, but: at least two other test suites
> in selftests/ have had to recreate MIN() or min(), and probably a few
> other common things as well. It would be nice to gather up some of these
> common things into one of the shared header files in selftests/.
>
> I'm certainly not saying that this patchset has that responsibility,
> though. Just pointing it out in case someone has a moment to clean up a
> few here and there.
Thanks for pointing this out. I'll leave it as a task for a separate
patch if time permits or no one gets around to it before :-)
>
> I'll assume that any changes to make things fit within 80 cols are
> trivial, so you can add:
>
> Reviewed-by: John Hubbard
>
> thanks,
> --
> John Hubbard
> NVIDIA
>
> > +
> > +struct config {
> > + unsigned long long src_alignment;
> > + unsigned long long dest_alignment;
> > + unsigned long long region_size;
> > + int overlapping;
> > +};
> > +
> > +struct test {
> > + const char *name;
> > + struct config config;
> > + int expect_failure;
> > +};
> > +
> > +enum {
> > + _1KB = 1ULL << 10, /* 1KB -> not page aligned */
> > + _4KB = 4ULL << 10,
> > + _8KB = 8ULL << 10,
> > + _1MB = 1ULL << 20,
> > + _2MB = 2ULL << 20,
> > + _4MB = 4ULL << 20,
> > + _1GB = 1ULL << 30,
> > + _2GB = 2ULL << 30,
> > + PTE = _4KB,
> > + PMD = _2MB,
> > + PUD = _1GB,
> > +};
> > +
> > +#define MAKE_TEST(source_align, destination_align, size, \
> > + overlaps, should_fail, test_name) \
> > +{\
> > + .name = test_name, \
> > + .config = { \
> > + .src_alignment = source_align, \
> > + .dest_alignment = destination_align,\
> > + .region_size = size,\
> > + .overlapping = overlaps,\
> > + }, \
> > + .expect_failure = should_fail \
> > +}
> > +
> > +/*
> > + * Returns the start address of the mapping on success, else returns
> > + * NULL on failure.
> > + */
> > +static void *get_source_mapping(struct config c)
> > +{
> > + unsigned long long addr = 0ULL;
> > + void *src_addr = NULL;
> > +retry:
> > + addr += c.src_alignment;
> > + src_addr = mmap((void *) addr, c.region_size, PROT_READ | PROT_WRITE,
> > + MAP_FIXED | MAP_ANONYMOUS | MAP_SHARED, -1, 0);
> > + if (src_addr == MAP_FAILED) {
> > + if (errno == EPERM)
> > + goto retry;
> > + goto error;
> > + }
> > + /*
> > + * Check that the address is aligned to the specified alignment.
> > Add
