Add a KUnit test for the kernel hashtable implementation in include/linux/hashtable.h.
Note that this version does not yet test each of the rcu alternative versions of functions.
Signed-off-by: Rae Moar rmoar@google.com ---
Note: The check patch script is outputting open brace errors on lines 154, 186, 231 of lib/hashtable_test.c but I believe the format of the braces on those lines is consistent with the Linux Kernel style guide. Will continue to look at these errors.
lib/Kconfig.debug | 13 ++ lib/Makefile | 1 + lib/hashtable_test.c | 299 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 313 insertions(+) create mode 100644 lib/hashtable_test.c
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3fc7abffc7aa..3cf3b6f8cff4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2458,6 +2458,19 @@ config LIST_KUNIT_TEST
If unsure, say N.
+config HASHTABLE_KUNIT_TEST + tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + This builds the hashtable KUnit test suite. + It tests the API and basic functionality of the functions + and associated macros defined in include/linux/hashtable.h. + For more information on KUnit and unit tests in general please refer + to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. + config LINEAR_RANGES_TEST tristate "KUnit test for linear_ranges" depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index 161d6a724ff7..9036d3aeee0a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -370,6 +370,7 @@ obj-$(CONFIG_PLDMFW) += pldmfw/ CFLAGS_bitfield_kunit.o := $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o +obj-$(CONFIG_HASHTABLE_KUNIT_TEST) += hashtable_test.o obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o obj-$(CONFIG_BITS_TEST) += test_bits.o obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o diff --git a/lib/hashtable_test.c b/lib/hashtable_test.c new file mode 100644 index 000000000000..7907df66a8e7 --- /dev/null +++ b/lib/hashtable_test.c @@ -0,0 +1,299 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit test for the Kernel Hashtable structures. + * + * Copyright (C) 2022, Google LLC. + * Author: Rae Moar rmoar@google.com + */ +#include <kunit/test.h> + +#include <linux/hashtable.h> + +struct hashtable_test_entry { + int key; + int data; + struct hlist_node node; + int visited; +}; + +static void hashtable_test_hash_init(struct kunit *test) +{ + /* Test the different ways of initialising a hashtable. */ + DEFINE_HASHTABLE(hash1, 3); + DECLARE_HASHTABLE(hash2, 3); + + hash_init(hash1); + hash_init(hash2); + + KUNIT_EXPECT_TRUE(test, hash_empty(hash1)); + KUNIT_EXPECT_TRUE(test, hash_empty(hash2)); +} + +static void hashtable_test_hash_empty(struct kunit *test) +{ + struct hashtable_test_entry a; + DEFINE_HASHTABLE(hash, 3); + + hash_init(hash); + KUNIT_EXPECT_TRUE(test, hash_empty(hash)); + + a.key = 1; + a.data = 13; + hash_add(hash, &a.node, a.key); + + /* Hashtable should no longer be empty. */ + KUNIT_EXPECT_FALSE(test, hash_empty(hash)); +} + +static void hashtable_test_hash_hashed(struct kunit *test) +{ + struct hashtable_test_entry a, b; + DEFINE_HASHTABLE(hash, 3); + + hash_init(hash); + a.key = 1; + a.data = 13; + b.key = 1; + b.data = 2; + + hash_add(hash, &a.node, a.key); + hash_add(hash, &b.node, b.key); + + KUNIT_EXPECT_TRUE(test, hash_hashed(&a.node)); + KUNIT_EXPECT_TRUE(test, hash_hashed(&b.node)); +} + +static void hashtable_test_hash_add(struct kunit *test) +{ + struct hashtable_test_entry a, b, *x; + int bkt; + DEFINE_HASHTABLE(hash, 3); + + hash_init(hash); + a.key = 1; + a.data = 13; + a.visited = 0; + b.key = 2; + b.data = 10; + b.visited = 0; + + hash_add(hash, &a.node, a.key); + hash_add(hash, &b.node, b.key); + + hash_for_each(hash, bkt, x, node) { + if (x->key == a.key && x->data == a.data) + a.visited += 1; + if (x->key == b.key && x->data == b.data) + b.visited += 1; + } + + /* Both entries should have been visited exactly once. */ + KUNIT_EXPECT_EQ(test, a.visited, 1); + KUNIT_EXPECT_EQ(test, b.visited, 1); +} + +static void hashtable_test_hash_del(struct kunit *test) +{ + struct hashtable_test_entry a, b, *x; + DEFINE_HASHTABLE(hash, 3); + + hash_init(hash); + a.key = 1; + a.data = 13; + b.key = 2; + b.data = 10; + b.visited = 0; + + hash_add(hash, &a.node, a.key); + hash_add(hash, &b.node, b.key); + + hash_del(&b.node); + hash_for_each_possible(hash, x, node, b.key) { + if (x->key == b.key && x->data == b.data) + b.visited += 1; + } + + /* The deleted entry should not have been visited. */ + KUNIT_EXPECT_EQ(test, b.visited, 0); + + hash_del(&a.node); + + /* The hashtable should be empty. */ + KUNIT_EXPECT_TRUE(test, hash_empty(hash)); +} + +static void hashtable_test_hash_for_each(struct kunit *test) +{ + struct hashtable_test_entry entries[3]; + struct hashtable_test_entry *x; + int bkt, i, j, count; + DEFINE_HASHTABLE(hash, 3); + + /* Initialize a hashtable with three entries. */ + hash_init(hash); + for (i = 0; i < 3; i++) { + entries[i].key = i; + entries[i].data = i + 10; + entries[i].visited = 0; + hash_add(hash, &entries[i].node, entries[i].key); + } + + count = 0; + hash_for_each(hash, bkt, x, node) { + if (x->key >= 0 && x->key < 3) + entries[x->key].visited += 1; + count++; + } + + /* Should have visited each entry exactly once. */ + KUNIT_EXPECT_EQ(test, count, 3); + for (j = 0; j < 3; j++) + KUNIT_EXPECT_EQ(test, entries[j].visited, 1); +} + +static void hashtable_test_hash_for_each_safe(struct kunit *test) +{ + struct hashtable_test_entry entries[3]; + struct hashtable_test_entry *x; + struct hlist_node *tmp; + int bkt, i, j, count; + DEFINE_HASHTABLE(hash, 3); + + /* Initialize a hashtable with three entries. */ + hash_init(hash); + for (i = 0; i < 3; i++) { + entries[i].key = i; + entries[i].data = i + 10; + entries[i].visited = 0; + hash_add(hash, &entries[i].node, entries[i].key); + } + + count = 0; + hash_for_each_safe(hash, bkt, tmp, x, node) { + if (x->key >= 0 && x->key < 3) { + entries[x->key].visited += 1; + hash_del(&entries[x->key].node); + } + count++; + } + + /* Should have visited each entry exactly once. */ + KUNIT_EXPECT_EQ(test, count, 3); + for (j = 0; j < 3; j++) + KUNIT_EXPECT_EQ(test, entries[j].visited, 1); +} + +static void hashtable_test_hash_for_each_possible(struct kunit *test) +{ + struct hashtable_test_entry entries[4]; + struct hashtable_test_entry *x; + int i, j, count; + DEFINE_HASHTABLE(hash, 3); + + /* Initialize a hashtable with three entries with key = 1. */ + hash_init(hash); + for (i = 0; i < 3; i++) { + entries[i].key = 1; + entries[i].data = i; + entries[i].visited = 0; + hash_add(hash, &entries[i].node, entries[i].key); + } + + /* Add an entry with key = 2. */ + entries[3].key = 2; + entries[3].data = 3; + entries[3].visited = 0; + hash_add(hash, &entries[3].node, entries[3].key); + + count = 0; + hash_for_each_possible(hash, x, node, 1) { + if (x->data >= 0 && x->data < 4) + entries[x->data].visited += 1; + count++; + } + + /* Should have visited each entry with key = 1 exactly once. */ + for (j = 0; j < 3; j++) + KUNIT_EXPECT_EQ(test, entries[j].visited, 1); + + /* If entry with key = 2 is in the same bucket as the entries with + * key = 1, check it was visited. Otherwise ensure that only three + * entries were visited. + */ + if (hash_min(1, HASH_BITS(hash)) == hash_min(2, HASH_BITS(hash))) { + KUNIT_EXPECT_EQ(test, count, 4); + KUNIT_EXPECT_EQ(test, entries[3].visited, 1); + } else { + KUNIT_EXPECT_EQ(test, count, 3); + } +} + +static void hashtable_test_hash_for_each_possible_safe(struct kunit *test) +{ + struct hashtable_test_entry entries[4]; + struct hashtable_test_entry *x; + struct hlist_node *tmp; + int i, j, count; + DEFINE_HASHTABLE(hash, 3); + + /* Initialize a hashtable with three entries with key = 1. */ + hash_init(hash); + for (i = 0; i < 3; i++) { + entries[i].key = 1; + entries[i].data = i; + entries[i].visited = 0; + hash_add(hash, &entries[i].node, entries[i].key); + } + + /* Add an entry with key = 2. */ + entries[3].key = 2; + entries[3].data = 3; + entries[3].visited = 0; + hash_add(hash, &entries[3].node, entries[3].key); + + count = 0; + hash_for_each_possible_safe(hash, x, tmp, node, 1) { + if (x->data >= 0 && x->data < 4) { + entries[x->data].visited += 1; + hash_del(&entries[x->data].node); + } + count++; + } + + /* Should have visited each entry with key = 1 exactly once. */ + for (j = 0; j < 3; j++) + KUNIT_EXPECT_EQ(test, entries[j].visited, 1); + + /* If entry with key = 2 is in the same bucket as the entries with + * key = 1, check it was visited. Otherwise ensure that only three + * entries were visited. + */ + if (hash_min(1, HASH_BITS(hash)) == hash_min(2, HASH_BITS(hash))) { + KUNIT_EXPECT_EQ(test, count, 4); + KUNIT_EXPECT_EQ(test, entries[3].visited, 1); + } else { + KUNIT_EXPECT_EQ(test, count, 3); + } +} + +static struct kunit_case hashtable_test_cases[] = { + KUNIT_CASE(hashtable_test_hash_init), + KUNIT_CASE(hashtable_test_hash_empty), + KUNIT_CASE(hashtable_test_hash_hashed), + KUNIT_CASE(hashtable_test_hash_add), + KUNIT_CASE(hashtable_test_hash_del), + KUNIT_CASE(hashtable_test_hash_for_each), + KUNIT_CASE(hashtable_test_hash_for_each_safe), + KUNIT_CASE(hashtable_test_hash_for_each_possible), + KUNIT_CASE(hashtable_test_hash_for_each_possible_safe), + {}, +}; + +static struct kunit_suite hashtable_test_module = { + .name = "hashtable", + .test_cases = hashtable_test_cases, +}; + +kunit_test_suites(&hashtable_test_module); + +MODULE_LICENSE("GPL");
base-commit: 054be257f28ca8eeb8e3620766501b81ceb4b293
On Mon, Dec 19, 2022 at 7:16 PM Rae Moar rmoar@google.com wrote:
Add a KUnit test for the kernel hashtable implementation in include/linux/hashtable.h.
Note that this version does not yet test each of the rcu alternative versions of functions.
Signed-off-by: Rae Moar rmoar@google.com
Looks pretty good from a cursory glance. Had some mostly stylistic nits/suggestions below.
Note: The check patch script is outputting open brace errors on lines 154, 186, 231 of lib/hashtable_test.c but I believe the format of the braces on those lines is consistent with the Linux Kernel style guide. Will continue to look at these errors.
lib/Kconfig.debug | 13 ++ lib/Makefile | 1 + lib/hashtable_test.c | 299 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 313 insertions(+) create mode 100644 lib/hashtable_test.c
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3fc7abffc7aa..3cf3b6f8cff4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2458,6 +2458,19 @@ config LIST_KUNIT_TEST
If unsure, say N.+config HASHTABLE_KUNIT_TEST
tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTSdepends on KUNITdefault KUNIT_ALL_TESTShelpThis builds the hashtable KUnit test suite.It tests the API and basic functionality of the functionsand associated macros defined in include/linux/hashtable.h.
nit: the "functions and associated macros" == "the API", so perhaps we can shorten this a bit.
For more information on KUnit and unit tests in general please referto the KUnit documentation in Documentation/dev-tools/kunit/.If unsure, say N.config LINEAR_RANGES_TEST tristate "KUnit test for linear_ranges" depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index 161d6a724ff7..9036d3aeee0a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -370,6 +370,7 @@ obj-$(CONFIG_PLDMFW) += pldmfw/ CFLAGS_bitfield_kunit.o := $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o +obj-$(CONFIG_HASHTABLE_KUNIT_TEST) += hashtable_test.o obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o obj-$(CONFIG_BITS_TEST) += test_bits.o obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o diff --git a/lib/hashtable_test.c b/lib/hashtable_test.c new file mode 100644 index 000000000000..7907df66a8e7 --- /dev/null +++ b/lib/hashtable_test.c @@ -0,0 +1,299 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- KUnit test for the Kernel Hashtable structures.
- Copyright (C) 2022, Google LLC.
- Author: Rae Moar rmoar@google.com
- */
+#include <kunit/test.h>
+#include <linux/hashtable.h>
+struct hashtable_test_entry {
int key;int data;struct hlist_node node;int visited;+};
+static void hashtable_test_hash_init(struct kunit *test) +{
/* Test the different ways of initialising a hashtable. */DEFINE_HASHTABLE(hash1, 3);DECLARE_HASHTABLE(hash2, 3);hash_init(hash1);hash_init(hash2);KUNIT_EXPECT_TRUE(test, hash_empty(hash1));KUNIT_EXPECT_TRUE(test, hash_empty(hash2));+}
+static void hashtable_test_hash_empty(struct kunit *test) +{
struct hashtable_test_entry a;DEFINE_HASHTABLE(hash, 3);hash_init(hash);KUNIT_EXPECT_TRUE(test, hash_empty(hash));a.key = 1;a.data = 13;hash_add(hash, &a.node, a.key);/* Hashtable should no longer be empty. */KUNIT_EXPECT_FALSE(test, hash_empty(hash));+}
+static void hashtable_test_hash_hashed(struct kunit *test) +{
struct hashtable_test_entry a, b;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;b.key = 1;b.data = 2;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);KUNIT_EXPECT_TRUE(test, hash_hashed(&a.node));KUNIT_EXPECT_TRUE(test, hash_hashed(&b.node));+}
+static void hashtable_test_hash_add(struct kunit *test) +{
struct hashtable_test_entry a, b, *x;int bkt;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;a.visited = 0;b.key = 2;b.data = 10;b.visited = 0;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);hash_for_each(hash, bkt, x, node) {if (x->key == a.key && x->data == a.data)a.visited += 1;if (x->key == b.key && x->data == b.data)b.visited += 1;}
x->visited += 1; or x->visited++; also do the same thing.
Note: given x is supposed to point to a or b, I don't know if checking against a.data does us much good. If we're trying to check that hash_add() doesn't mutate the keys and data, this code won't catch it. We'd have to instead do something like if(x->key != 1 && x->key != 2) KUNIT_FAIL(test, ...);
/* Both entries should have been visited exactly once. */KUNIT_EXPECT_EQ(test, a.visited, 1);KUNIT_EXPECT_EQ(test, b.visited, 1);+}
+static void hashtable_test_hash_del(struct kunit *test) +{
struct hashtable_test_entry a, b, *x;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;b.key = 2;b.data = 10;b.visited = 0;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);hash_del(&b.node);hash_for_each_possible(hash, x, node, b.key) {if (x->key == b.key && x->data == b.data)b.visited += 1;
Similarly to above, x->visited += 1 (or ++) is probably better.
}/* The deleted entry should not have been visited. */KUNIT_EXPECT_EQ(test, b.visited, 0);hash_del(&a.node);/* The hashtable should be empty. */KUNIT_EXPECT_TRUE(test, hash_empty(hash));+}
+static void hashtable_test_hash_for_each(struct kunit *test) +{
struct hashtable_test_entry entries[3];struct hashtable_test_entry *x;int bkt, i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = i;entries[i].data = i + 10;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}count = 0;hash_for_each(hash, bkt, x, node) {if (x->key >= 0 && x->key < 3)entries[x->key].visited += 1;
Would this be better using an assert to fail the test if we see unexpected keys? E.g. like if (x->key < 0 || x->key > 3) KUNIT_ASSERT_FAILURE(test, ...); x->visited++; count++; or KUNIT_ASSERT_GE(test, x->key, 0); KUNIT_ASSERT_LT(test, x->key, 3);
count++;}/* Should have visited each entry exactly once. */KUNIT_EXPECT_EQ(test, count, 3);for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);+}
+static void hashtable_test_hash_for_each_safe(struct kunit *test) +{
struct hashtable_test_entry entries[3];struct hashtable_test_entry *x;struct hlist_node *tmp;int bkt, i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = i;entries[i].data = i + 10;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}count = 0;hash_for_each_safe(hash, bkt, tmp, x, node) {if (x->key >= 0 && x->key < 3) {entries[x->key].visited += 1;hash_del(&entries[x->key].node);}count++;}/* Should have visited each entry exactly once. */KUNIT_EXPECT_EQ(test, count, 3);for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);+}
+static void hashtable_test_hash_for_each_possible(struct kunit *test) +{
struct hashtable_test_entry entries[4];struct hashtable_test_entry *x;int i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries with key = 1. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = 1;entries[i].data = i;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}/* Add an entry with key = 2. */entries[3].key = 2;entries[3].data = 3;entries[3].visited = 0;hash_add(hash, &entries[3].node, entries[3].key);count = 0;hash_for_each_possible(hash, x, node, 1) {if (x->data >= 0 && x->data < 4)entries[x->data].visited += 1;count++;}/* Should have visited each entry with key = 1 exactly once. */for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);/* If entry with key = 2 is in the same bucket as the entries with* key = 1, check it was visited. Otherwise ensure that only three* entries were visited.*/if (hash_min(1, HASH_BITS(hash)) == hash_min(2, HASH_BITS(hash))) {
nit: this feels like we might be a bit too tied to the impl (not sure if it'll change anytime soon, but still).
Could we check the bucket using hash_for_each? E.g.
// assume we change the keys from {1,2} to {0,1} int buckets[2]; hash_for_each(hash, bkt, x, node) { buckets[x->key] = bkt; }
if (buckets[0] == buckets[1]) { // all in the same bucket ... } else { ... }
KUNIT_EXPECT_EQ(test, count, 4);KUNIT_EXPECT_EQ(test, entries[3].visited, 1);} else {KUNIT_EXPECT_EQ(test, count, 3);
should we also check that entries[3].visited == 0?
Daniel
On Tue, 20 Dec 2022 at 11:16, Rae Moar rmoar@google.com wrote:
Add a KUnit test for the kernel hashtable implementation in include/linux/hashtable.h.
Note that this version does not yet test each of the rcu alternative versions of functions.
Signed-off-by: Rae Moar rmoar@google.com
Thanks for completing the triangle (hash, list, hashtable) of hashtable-related tests!
This looks good to me, save for some nitpicks below. They're mostly pretty similar to Daniel's comments, so should be pretty straightforward.
Cheers, -- David
Note: The check patch script is outputting open brace errors on lines 154, 186, 231 of lib/hashtable_test.c but I believe the format of the braces on those lines is consistent with the Linux Kernel style guide. Will continue to look at these errors.
This is a problem we hit with the list test as well: because these functions have for_each in their name, checkpatch.pl assumes they're loops (using the macro), not functions.
As with the list test, we _could_ try to fix this in checkpatch, or rename the tests, but I suspect it's a special enough case (naming a function after a macro), that it's best to ignore the warnings, keeping a note like this in the patch email.
Maybe one day, checkpatch.pl will be able to tell that this is a function...
lib/Kconfig.debug | 13 ++ lib/Makefile | 1 + lib/hashtable_test.c | 299 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 313 insertions(+) create mode 100644 lib/hashtable_test.c
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3fc7abffc7aa..3cf3b6f8cff4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2458,6 +2458,19 @@ config LIST_KUNIT_TEST
If unsure, say N.+config HASHTABLE_KUNIT_TEST
tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTSdepends on KUNITdefault KUNIT_ALL_TESTShelpThis builds the hashtable KUnit test suite.It tests the API and basic functionality of the functionsand associated macros defined in include/linux/hashtable.h.For more information on KUnit and unit tests in general please referto the KUnit documentation in Documentation/dev-tools/kunit/.If unsure, say N.config LINEAR_RANGES_TEST tristate "KUnit test for linear_ranges" depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index 161d6a724ff7..9036d3aeee0a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -370,6 +370,7 @@ obj-$(CONFIG_PLDMFW) += pldmfw/ CFLAGS_bitfield_kunit.o := $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o +obj-$(CONFIG_HASHTABLE_KUNIT_TEST) += hashtable_test.o obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o obj-$(CONFIG_BITS_TEST) += test_bits.o obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o diff --git a/lib/hashtable_test.c b/lib/hashtable_test.c new file mode 100644 index 000000000000..7907df66a8e7 --- /dev/null +++ b/lib/hashtable_test.c @@ -0,0 +1,299 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- KUnit test for the Kernel Hashtable structures.
- Copyright (C) 2022, Google LLC.
- Author: Rae Moar rmoar@google.com
- */
+#include <kunit/test.h>
+#include <linux/hashtable.h>
+struct hashtable_test_entry {
int key;int data;struct hlist_node node;int visited;+};
+static void hashtable_test_hash_init(struct kunit *test) +{
/* Test the different ways of initialising a hashtable. */DEFINE_HASHTABLE(hash1, 3);DECLARE_HASHTABLE(hash2, 3);hash_init(hash1);hash_init(hash2);KUNIT_EXPECT_TRUE(test, hash_empty(hash1));KUNIT_EXPECT_TRUE(test, hash_empty(hash2));+}
+static void hashtable_test_hash_empty(struct kunit *test) +{
struct hashtable_test_entry a;DEFINE_HASHTABLE(hash, 3);hash_init(hash);KUNIT_EXPECT_TRUE(test, hash_empty(hash));a.key = 1;a.data = 13;hash_add(hash, &a.node, a.key);/* Hashtable should no longer be empty. */KUNIT_EXPECT_FALSE(test, hash_empty(hash));+}
+static void hashtable_test_hash_hashed(struct kunit *test) +{
struct hashtable_test_entry a, b;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;b.key = 1;b.data = 2;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);KUNIT_EXPECT_TRUE(test, hash_hashed(&a.node));KUNIT_EXPECT_TRUE(test, hash_hashed(&b.node));+}
+static void hashtable_test_hash_add(struct kunit *test) +{
struct hashtable_test_entry a, b, *x;int bkt;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;a.visited = 0;b.key = 2;b.data = 10;b.visited = 0;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);hash_for_each(hash, bkt, x, node) {if (x->key == a.key && x->data == a.data)a.visited += 1;if (x->key == b.key && x->data == b.data)b.visited += 1;
I think we could improve this by checking 'x->key' is one of {a,b}. Daniel's suggestions below are good, otherwise perhaps something like: x->visited++; if (x->key == a.key) KUNIT_EXPECT_EQ(x->data, a.data); else if (x->key == b.key) KUNIT_EXPECT_EQ(x->data, b.data); else KUNIT_EXPECT_NEQ(x->key, x->key); /* Not an expected key. */
The other, more over-the-top option would be to have an array of struct hashtable_test_entry, rather than separate a and b variables, and to loop over them, e.g. x->visited++; for (int i = 0; i < ARRAY_SIZE(entries); ++i) { if (entires[i]->key == x->key) { … break; } KUNIT_EXPECT_NEQ_MSG(x->key, x->key, "Unexxpected element in hashtable"); }
But I suspect the first is actually cleaner.
}/* Both entries should have been visited exactly once. */KUNIT_EXPECT_EQ(test, a.visited, 1);KUNIT_EXPECT_EQ(test, b.visited, 1);+}
+static void hashtable_test_hash_del(struct kunit *test) +{
struct hashtable_test_entry a, b, *x;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;b.key = 2;b.data = 10;b.visited = 0;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);hash_del(&b.node);hash_for_each_possible(hash, x, node, b.key) {if (x->key == b.key && x->data == b.data)b.visited += 1;
Again, just increment x->visited here, and possibly add KUNIT_EXPECT_NEQ(x->key, b.key).
}/* The deleted entry should not have been visited. */KUNIT_EXPECT_EQ(test, b.visited, 0);hash_del(&a.node);/* The hashtable should be empty. */KUNIT_EXPECT_TRUE(test, hash_empty(hash));+}
+static void hashtable_test_hash_for_each(struct kunit *test) +{
struct hashtable_test_entry entries[3];struct hashtable_test_entry *x;int bkt, i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = i;entries[i].data = i + 10;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}count = 0;hash_for_each(hash, bkt, x, node) {if (x->key >= 0 && x->key < 3)entries[x->key].visited += 1;
Again, let's just increment x->visited, and maybe KUNIT_EXPECT_GEQ(x->key, 0), ..._LEQ(x->key, 3).
count++;}/* Should have visited each entry exactly once. */KUNIT_EXPECT_EQ(test, count, 3);for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);+}
+static void hashtable_test_hash_for_each_safe(struct kunit *test) +{
struct hashtable_test_entry entries[3];struct hashtable_test_entry *x;struct hlist_node *tmp;int bkt, i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = i;entries[i].data = i + 10;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}count = 0;hash_for_each_safe(hash, bkt, tmp, x, node) {if (x->key >= 0 && x->key < 3) {entries[x->key].visited += 1;hash_del(&entries[x->key].node);}count++;}/* Should have visited each entry exactly once. */KUNIT_EXPECT_EQ(test, count, 3);for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);+}
+static void hashtable_test_hash_for_each_possible(struct kunit *test) +{
struct hashtable_test_entry entries[4];struct hashtable_test_entry *x;int i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries with key = 1. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = 1;entries[i].data = i;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}/* Add an entry with key = 2. */entries[3].key = 2;entries[3].data = 3;entries[3].visited = 0;hash_add(hash, &entries[3].node, entries[3].key);count = 0;hash_for_each_possible(hash, x, node, 1) {if (x->data >= 0 && x->data < 4)entries[x->data].visited += 1;count++;}/* Should have visited each entry with key = 1 exactly once. */for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);/* If entry with key = 2 is in the same bucket as the entries with* key = 1, check it was visited. Otherwise ensure that only three* entries were visited.*/if (hash_min(1, HASH_BITS(hash)) == hash_min(2, HASH_BITS(hash))) {KUNIT_EXPECT_EQ(test, count, 4);KUNIT_EXPECT_EQ(test, entries[3].visited, 1);} else {KUNIT_EXPECT_EQ(test, count, 3);}
I'm a bit on-the-fence about whether or not this is too implementation-specific. I think the way the hashtable works here is supposed to be stable, but given that almost nothing in the actual kernel seems to rely on hash_min directly, maybe it's better to not lock it in with a test.
How about reducing this to a KUNIT_EXPECT_GEQ(test, count, 4)?
+}
+static void hashtable_test_hash_for_each_possible_safe(struct kunit *test) +{
struct hashtable_test_entry entries[4];struct hashtable_test_entry *x;struct hlist_node *tmp;int i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries with key = 1. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = 1;entries[i].data = i;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}/* Add an entry with key = 2. */entries[3].key = 2;entries[3].data = 3;entries[3].visited = 0;hash_add(hash, &entries[3].node, entries[3].key);count = 0;hash_for_each_possible_safe(hash, x, tmp, node, 1) {if (x->data >= 0 && x->data < 4) {entries[x->data].visited += 1;hash_del(&entries[x->data].node);}count++;}/* Should have visited each entry with key = 1 exactly once. */for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);/* If entry with key = 2 is in the same bucket as the entries with* key = 1, check it was visited. Otherwise ensure that only three* entries were visited.*/if (hash_min(1, HASH_BITS(hash)) == hash_min(2, HASH_BITS(hash))) {KUNIT_EXPECT_EQ(test, count, 4);KUNIT_EXPECT_EQ(test, entries[3].visited, 1);} else {KUNIT_EXPECT_EQ(test, count, 3);}+}
+static struct kunit_case hashtable_test_cases[] = {
KUNIT_CASE(hashtable_test_hash_init),KUNIT_CASE(hashtable_test_hash_empty),KUNIT_CASE(hashtable_test_hash_hashed),KUNIT_CASE(hashtable_test_hash_add),KUNIT_CASE(hashtable_test_hash_del),KUNIT_CASE(hashtable_test_hash_for_each),KUNIT_CASE(hashtable_test_hash_for_each_safe),KUNIT_CASE(hashtable_test_hash_for_each_possible),KUNIT_CASE(hashtable_test_hash_for_each_possible_safe),{},+};
+static struct kunit_suite hashtable_test_module = {
.name = "hashtable",.test_cases = hashtable_test_cases,+};
+kunit_test_suites(&hashtable_test_module);
+MODULE_LICENSE("GPL");
base-commit: 054be257f28ca8eeb8e3620766501b81ceb4b293
2.39.0.314.g84b9a713c41-goog
On Tue, Dec 27, 2022 at 9:00 PM Daniel Latypov dlatypov@google.com wrote:
On Mon, Dec 19, 2022 at 7:16 PM Rae Moar rmoar@google.com wrote:
Add a KUnit test for the kernel hashtable implementation in include/linux/hashtable.h.
Note that this version does not yet test each of the rcu alternative versions of functions.
Signed-off-by: Rae Moar rmoar@google.com
Looks pretty good from a cursory glance. Had some mostly stylistic nits/suggestions below.
Note: The check patch script is outputting open brace errors on lines 154, 186, 231 of lib/hashtable_test.c but I believe the format of the braces on those lines is consistent with the Linux Kernel style guide. Will continue to look at these errors.
lib/Kconfig.debug | 13 ++ lib/Makefile | 1 + lib/hashtable_test.c | 299 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 313 insertions(+) create mode 100644 lib/hashtable_test.c
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3fc7abffc7aa..3cf3b6f8cff4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2458,6 +2458,19 @@ config LIST_KUNIT_TEST
If unsure, say N.+config HASHTABLE_KUNIT_TEST
tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTSdepends on KUNITdefault KUNIT_ALL_TESTShelpThis builds the hashtable KUnit test suite.It tests the API and basic functionality of the functionsand associated macros defined in include/linux/hashtable.h.nit: the "functions and associated macros" == "the API", so perhaps we can shorten this a bit.
This seems better to me. Thanks!
For more information on KUnit and unit tests in general please referto the KUnit documentation in Documentation/dev-tools/kunit/.If unsure, say N.config LINEAR_RANGES_TEST tristate "KUnit test for linear_ranges" depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index 161d6a724ff7..9036d3aeee0a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -370,6 +370,7 @@ obj-$(CONFIG_PLDMFW) += pldmfw/ CFLAGS_bitfield_kunit.o := $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o +obj-$(CONFIG_HASHTABLE_KUNIT_TEST) += hashtable_test.o obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o obj-$(CONFIG_BITS_TEST) += test_bits.o obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o diff --git a/lib/hashtable_test.c b/lib/hashtable_test.c new file mode 100644 index 000000000000..7907df66a8e7 --- /dev/null +++ b/lib/hashtable_test.c @@ -0,0 +1,299 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- KUnit test for the Kernel Hashtable structures.
- Copyright (C) 2022, Google LLC.
- Author: Rae Moar rmoar@google.com
- */
+#include <kunit/test.h>
+#include <linux/hashtable.h>
+struct hashtable_test_entry {
int key;int data;struct hlist_node node;int visited;+};
+static void hashtable_test_hash_init(struct kunit *test) +{
/* Test the different ways of initialising a hashtable. */DEFINE_HASHTABLE(hash1, 3);DECLARE_HASHTABLE(hash2, 3);hash_init(hash1);hash_init(hash2);KUNIT_EXPECT_TRUE(test, hash_empty(hash1));KUNIT_EXPECT_TRUE(test, hash_empty(hash2));+}
+static void hashtable_test_hash_empty(struct kunit *test) +{
struct hashtable_test_entry a;DEFINE_HASHTABLE(hash, 3);hash_init(hash);KUNIT_EXPECT_TRUE(test, hash_empty(hash));a.key = 1;a.data = 13;hash_add(hash, &a.node, a.key);/* Hashtable should no longer be empty. */KUNIT_EXPECT_FALSE(test, hash_empty(hash));+}
+static void hashtable_test_hash_hashed(struct kunit *test) +{
struct hashtable_test_entry a, b;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;b.key = 1;b.data = 2;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);KUNIT_EXPECT_TRUE(test, hash_hashed(&a.node));KUNIT_EXPECT_TRUE(test, hash_hashed(&b.node));+}
+static void hashtable_test_hash_add(struct kunit *test) +{
struct hashtable_test_entry a, b, *x;int bkt;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;a.visited = 0;b.key = 2;b.data = 10;b.visited = 0;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);hash_for_each(hash, bkt, x, node) {if (x->key == a.key && x->data == a.data)a.visited += 1;if (x->key == b.key && x->data == b.data)b.visited += 1;}x->visited += 1; or x->visited++; also do the same thing.
Oh right. That makes a lot of sense.
Note: given x is supposed to point to a or b, I don't know if checking against a.data does us much good. If we're trying to check that hash_add() doesn't mutate the keys and data, this code won't catch it. We'd have to instead do something like if(x->key != 1 && x->key != 2) KUNIT_FAIL(test, ...);
This seems like a good change to me in combination with changing it to x->visited++;. Although David's suggestion might be slightly more exhaustive. Why wouldn't it be important to check that the key matches the data?
/* Both entries should have been visited exactly once. */KUNIT_EXPECT_EQ(test, a.visited, 1);KUNIT_EXPECT_EQ(test, b.visited, 1);+}
+static void hashtable_test_hash_del(struct kunit *test) +{
struct hashtable_test_entry a, b, *x;DEFINE_HASHTABLE(hash, 3);hash_init(hash);a.key = 1;a.data = 13;b.key = 2;b.data = 10;b.visited = 0;hash_add(hash, &a.node, a.key);hash_add(hash, &b.node, b.key);hash_del(&b.node);hash_for_each_possible(hash, x, node, b.key) {if (x->key == b.key && x->data == b.data)b.visited += 1;Similarly to above, x->visited += 1 (or ++) is probably better.
Right. Will switch this out here.
}/* The deleted entry should not have been visited. */KUNIT_EXPECT_EQ(test, b.visited, 0);hash_del(&a.node);/* The hashtable should be empty. */KUNIT_EXPECT_TRUE(test, hash_empty(hash));+}
+static void hashtable_test_hash_for_each(struct kunit *test) +{
struct hashtable_test_entry entries[3];struct hashtable_test_entry *x;int bkt, i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = i;entries[i].data = i + 10;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}count = 0;hash_for_each(hash, bkt, x, node) {if (x->key >= 0 && x->key < 3)entries[x->key].visited += 1;Would this be better using an assert to fail the test if we see unexpected keys? E.g. like if (x->key < 0 || x->key > 3) KUNIT_ASSERT_FAILURE(test, ...); x->visited++; count++; or KUNIT_ASSERT_GE(test, x->key, 0); KUNIT_ASSERT_LT(test, x->key, 3);
Yes, this makes a lot of sense. I will switch out just the if statements for using assert statements.
count++;}/* Should have visited each entry exactly once. */KUNIT_EXPECT_EQ(test, count, 3);for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);+}
+static void hashtable_test_hash_for_each_safe(struct kunit *test) +{
struct hashtable_test_entry entries[3];struct hashtable_test_entry *x;struct hlist_node *tmp;int bkt, i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = i;entries[i].data = i + 10;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}count = 0;hash_for_each_safe(hash, bkt, tmp, x, node) {if (x->key >= 0 && x->key < 3) {entries[x->key].visited += 1;hash_del(&entries[x->key].node);}count++;}/* Should have visited each entry exactly once. */KUNIT_EXPECT_EQ(test, count, 3);for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);+}
+static void hashtable_test_hash_for_each_possible(struct kunit *test) +{
struct hashtable_test_entry entries[4];struct hashtable_test_entry *x;int i, j, count;DEFINE_HASHTABLE(hash, 3);/* Initialize a hashtable with three entries with key = 1. */hash_init(hash);for (i = 0; i < 3; i++) {entries[i].key = 1;entries[i].data = i;entries[i].visited = 0;hash_add(hash, &entries[i].node, entries[i].key);}/* Add an entry with key = 2. */entries[3].key = 2;entries[3].data = 3;entries[3].visited = 0;hash_add(hash, &entries[3].node, entries[3].key);count = 0;hash_for_each_possible(hash, x, node, 1) {if (x->data >= 0 && x->data < 4)entries[x->data].visited += 1;count++;}/* Should have visited each entry with key = 1 exactly once. */for (j = 0; j < 3; j++)KUNIT_EXPECT_EQ(test, entries[j].visited, 1);/* If entry with key = 2 is in the same bucket as the entries with* key = 1, check it was visited. Otherwise ensure that only three* entries were visited.*/if (hash_min(1, HASH_BITS(hash)) == hash_min(2, HASH_BITS(hash))) {nit: this feels like we might be a bit too tied to the impl (not sure if it'll change anytime soon, but still).
Could we check the bucket using hash_for_each? E.g.
// assume we change the keys from {1,2} to {0,1} int buckets[2]; hash_for_each(hash, bkt, x, node) { buckets[x->key] = bkt; }
if (buckets[0] == buckets[1]) { // all in the same bucket ... } else { ... }
I really like the idea of using hash_for_each to determine the bucket. I will add this to the test.
KUNIT_EXPECT_EQ(test, count, 4);KUNIT_EXPECT_EQ(test, entries[3].visited, 1);} else {KUNIT_EXPECT_EQ(test, count, 3);should we also check that entries[3].visited == 0?
Right. Must have been a mistake on my end. Oops.
Daniel
Thanks Daniel! -Rae
On Fri, Jan 13, 2023 at 2:23 PM Rae Moar rmoar@google.com wrote:
<snip>
Note: given x is supposed to point to a or b, I don't know if checking against a.data does us much good. If we're trying to check that hash_add() doesn't mutate the keys and data, this code won't catch it. We'd have to instead do something like if(x->key != 1 && x->key != 2) KUNIT_FAIL(test, ...);
This seems like a good change to me in combination with changing it to x->visited++;. Although David's suggestion might be slightly more exhaustive. Why wouldn't it be important to check that the key matches the data?
Checks like KUNIT_EXPECT_EQ(test, x->data, a.data); won't do anything, given that x == &a. We're just comparing x->data to itself.
So we would have to write something instead like hash_for_each(hash, bkt, x, node) { x->visited++; if (x->key == a.key) { KUNIT_EXPECT_EQ(test, x->data, 13); } else if (x->key == b.key) { KUNIT_EXPECT_EQ(test, x->data, 10); } else { /* some call to KUNIT_FAIL about a bad key */ } }
Maybe that's worth it in one of the test cases, but I don't know if it's necessary to replicate this in the other places where we're incrementing `visited` by checking keys.
Daniel
linux-kselftest-mirror@lists.linaro.org
-
Daniel Latypov -
David Gow -
Rae Moar