misc lib/raid/ improvements

misc lib/raid/ improvements

[Christoph Hellwig]

Hi all,

this series improves the benchmark-based algorithm selection and
adds kunit benchmarks for both the XOR and raid6 libraries, and tidies
up a few very minor other bits.

diffstat:
 lib/raid/Kconfig                   |   15 ++++++
 lib/raid/raid6/Makefile            |    2 
 lib/raid/raid6/algos.c             |  112 +++++++++++++++++++++++++---------------------
 lib/raid/raid6/tests/raid6_kunit.c |   66 ++++++++++++++++++++++++++-
 lib/raid/xor/Makefile              |    2 
 lib/raid/xor/tests/Makefile        |    2 
 lib/raid/xor/tests/xor_kunit.c     |   64 +++++++++++++++++++++++++-
 lib/raid/xor/xor-core.c            |   55 ++++++++++------------
 8 files changed, 236 insertions(+), 82 deletions(-)

[PATCH 1/8] xor: enable lock context analysis

[Christoph Hellwig]

The code doesn't have any locking, so this is trivial.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/xor/Makefile       | 2 ++
 lib/raid/xor/tests/Makefile | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/lib/raid/xor/Makefile b/lib/raid/xor/Makefile
index e8ecec3c09f9..9b0fad459cdb 100644
--- a/lib/raid/xor/Makefile
+++ b/lib/raid/xor/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
+CONTEXT_ANALYSIS := y
+
 ccflags-y			+= -I $(src)
 
 obj-$(CONFIG_XOR_BLOCKS)	+= xor.o
diff --git a/lib/raid/xor/tests/Makefile b/lib/raid/xor/tests/Makefile
index 661e8f6ffd1f..1cce833cd7fd 100644
--- a/lib/raid/xor/tests/Makefile
+++ b/lib/raid/xor/tests/Makefile
@@ -1,3 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+CONTEXT_ANALYSIS := y
+
 obj-$(CONFIG_XOR_KUNIT_TEST) += xor_kunit.o
-- 
2.53.0

[PATCH 2/8] xor: improve the runtime selection benchmark

[Christoph Hellwig]

Use plain ktime_get_ns for the timing, use 4 + 1 disks for a realistic
load, and report the throughput on the data disks instead of the that
on the parity disk, which isn't all that useful.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/xor/xor-core.c | 55 +++++++++++++++++++----------------------
 1 file changed, 26 insertions(+), 29 deletions(-)

diff --git a/lib/raid/xor/xor-core.c b/lib/raid/xor/xor-core.c
index 50931fbf0324..a890cec21bbc 100644
--- a/lib/raid/xor/xor-core.c
+++ b/lib/raid/xor/xor-core.c
@@ -10,7 +10,6 @@
 #include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/raid/xor.h>
-#include <linux/jiffies.h>
 #include <linux/preempt.h>
 #include <linux/static_call.h>
 #include "xor_impl.h"
@@ -73,59 +72,56 @@ void __init xor_force(struct xor_block_template *tmpl)
 	forced_template = tmpl;
 }
 
-#define BENCH_SIZE	4096
+#define BENCH_SIZE	SZ_4K
+#define NR_SRCS		4
 #define REPS		800U
 
-static void __init
-do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
+static void __init do_xor_speed(struct xor_block_template *tmpl, void *dest,
+		void *srcs[NR_SRCS])
 {
-	int speed;
-	unsigned long reps;
-	ktime_t min, start, t0;
-	void *srcs[1] = { b2 };
+	u64 t;
+	int i;
 
 	preempt_disable();
-
-	reps = 0;
-	t0 = ktime_get();
-	/* delay start until time has advanced */
-	while ((start = ktime_get()) == t0)
-		cpu_relax();
-	do {
+	t = ktime_get_ns();
+	for (i = 0; i < REPS; i++) {
 		mb(); /* prevent loop optimization */
-		tmpl->xor_gen(b1, srcs, 1, BENCH_SIZE);
+		tmpl->xor_gen(dest, srcs, NR_SRCS, BENCH_SIZE);
 		mb();
-	} while (reps++ < REPS || (t0 = ktime_get()) == start);
-	min = ktime_sub(t0, start);
-
+	}
+	t = ktime_get_ns() - t;
 	preempt_enable();
 
-	// bytes/ns == GB/s, multiply by 1000 to get MB/s [not MiB/s]
-	speed = (1000 * reps * BENCH_SIZE) / (unsigned int)ktime_to_ns(min);
-	tmpl->speed = speed;
+	/* bytes/ns == GB/s, multiply by 1000 to get MB/s [not MiB/s] */
+	tmpl->speed = div64_u64((u64)BENCH_SIZE * REPS * NR_SRCS * 1000, t);
 
-	pr_info("   %-16s: %5d MB/sec\n", tmpl->name, speed);
+	pr_info("   %-16s: %5d MB/sec\n", tmpl->name, tmpl->speed);
 }
 
 static int __init calibrate_xor_blocks(void)
 {
-	void *b1, *b2;
 	struct xor_block_template *f, *fastest;
+	void *srcs[NR_SRCS];
+	void *buf, *dest;
+	int i;
 
 	if (forced_template)
 		return 0;
 
-	b1 = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
-	if (!b1) {
+	buf = kmalloc(BENCH_SIZE * (NR_SRCS + 1), GFP_KERNEL);
+	if (!buf) {
 		pr_warn("xor: Yikes!  No memory available.\n");
 		return -ENOMEM;
 	}
-	b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
+	get_random_bytes(buf, BENCH_SIZE * (NR_SRCS + 1));
+	dest = buf;
+	for (i = 0; i < NR_SRCS; i++)
+		srcs[i] = buf + (i + 1) * BENCH_SIZE;
 
 	pr_info("xor: measuring software checksum speed\n");
 	fastest = template_list;
 	for (f = template_list; f; f = f->next) {
-		do_xor_speed(f, b1, b2);
+		do_xor_speed(f, dest, srcs);
 		if (f->speed > fastest->speed)
 			fastest = f;
 	}
@@ -133,9 +129,10 @@ static int __init calibrate_xor_blocks(void)
 	pr_info("xor: using function: %s (%d MB/sec)\n",
 	       fastest->name, fastest->speed);
 
-	kfree(b1);
+	kfree(buf);
 	return 0;
 }
+#undef NR_SRCS
 
 #ifdef CONFIG_XOR_BLOCKS_ARCH
 #include "xor_arch.h" /* $SRCARCH/xor_arch.h */
-- 
2.53.0

[PATCH 3/8] xor/kunit: fix a spelling error

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/xor/tests/xor_kunit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/raid/xor/tests/xor_kunit.c b/lib/raid/xor/tests/xor_kunit.c
index 0c2a3a420bf9..659ae3edbc25 100644
--- a/lib/raid/xor/tests/xor_kunit.c
+++ b/lib/raid/xor/tests/xor_kunit.c
@@ -85,7 +85,7 @@ static void xor_test(struct kunit *test)
 			xor_generate_random_data();
 
 		/*
-		 * If we're not using the entire buffer size, inject randomize
+		 * If we're not using the entire buffer size, inject randomized
 		 * alignment into the buffer.
 		 */
 		max_alignment = XOR_KUNIT_MAX_BYTES - len;
-- 
2.53.0

[PATCH 4/8] xor/kunit: add a benchmark

[Christoph Hellwig]

Add a benchmark to test the XOR functions for more representative block
sizes and numbers of disks.  Including 64k would be useful here, but
increasing the test buffer size increases the runtime of the functional
kunit test too much unfortunately.

The runtime numbers are reported in GB/s as the numbers of modern
implementations are basically unreadable as MB/s.  This means
retro-architectures could report 0, but that is an easy tradeoff.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/Kconfig               |  6 ++++
 lib/raid/xor/tests/xor_kunit.c | 62 ++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/lib/raid/Kconfig b/lib/raid/Kconfig
index 978cd6ba08ac..c4eeb7c716c8 100644
--- a/lib/raid/Kconfig
+++ b/lib/raid/Kconfig
@@ -29,6 +29,12 @@ config XOR_KUNIT_TEST
 	  This is intended to help people writing architecture-specific
 	  optimized versions.  If unsure, say N.
 
+config XOR_BENCHMARK
+	bool "Benchmark for xor_gen"
+	depends on XOR_KUNIT_TEST
+	help
+	  Include benchmarks in the KUnit test suite for xor_gen.
+
 config RAID6_PQ
 	tristate
 
diff --git a/lib/raid/xor/tests/xor_kunit.c b/lib/raid/xor/tests/xor_kunit.c
index 659ae3edbc25..648c6da9464c 100644
--- a/lib/raid/xor/tests/xor_kunit.c
+++ b/lib/raid/xor/tests/xor_kunit.c
@@ -125,8 +125,70 @@ static void xor_test(struct kunit *test)
 	}
 }
 
+static void xor_benchmark(struct kunit *test)
+{
+	static const unsigned int nr_to_test[] = {
+		4, 5, 6, 7, 8, 10, 12, 15, 16, 32,
+	};
+	static const unsigned int len_to_test[] = {
+		SZ_4K, SZ_16K,
+	};
+	unsigned int i, j, l;
+	u64 t;
+
+	if (!IS_ENABLED(CONFIG_XOR_BENCHMARK))
+		kunit_skip(test, "not enabled");
+
+	/* warm-up */
+	for (i = 0; i < ARRAY_SIZE(nr_to_test); i++) {
+		for (j = 0; j < ARRAY_SIZE(len_to_test); j++) {
+			for (l = 0; l < 10; l++) {
+				xor_gen(test_dest, test_buffers, nr_to_test[i],
+						len_to_test[j]);
+			}
+		}
+	}
+
+	/*
+	 * Preferably this would be a loop over len_to_test, but the kunit
+	 * logging always adds a newline to each logged format string.
+	 */
+	static_assert(ARRAY_SIZE(len_to_test) == 2);
+	kunit_info(test, "          \t%5u bytes\t%5u bytes\n",
+			len_to_test[0], len_to_test[1]);
+
+	for (i = 0; i < ARRAY_SIZE(nr_to_test); i++) {
+		unsigned int nr = nr_to_test[i];
+		u64 speed[ARRAY_SIZE(len_to_test)];
+
+		KUNIT_ASSERT_LE(test, nr, XOR_KUNIT_MAX_BUFFERS);
+
+		for (j = 0; j < ARRAY_SIZE(len_to_test); j++) {
+			unsigned int len = len_to_test[j];
+			const unsigned long num_iters = 1000;
+
+			KUNIT_ASSERT_GT(test, len, 0);
+			KUNIT_ASSERT_LE(test, len, XOR_KUNIT_MAX_BYTES);
+
+			preempt_disable();
+			t = ktime_get_ns();
+			for (l = 0; l < num_iters; l++)
+				xor_gen(test_dest, test_buffers, nr, len);
+			t = ktime_get_ns() - t;
+			preempt_enable();
+
+			speed[j] = div64_u64((u64)len * num_iters * nr, t);
+		}
+
+		static_assert(ARRAY_SIZE(len_to_test) == 2);
+		kunit_info(test, "%3u disks:\t%5llu  GB/s\t%5llu  GB/s\n",
+				nr, speed[0], speed[1]);
+	}
+}
+
 static struct kunit_case xor_test_cases[] = {
 	KUNIT_CASE(xor_test),
+	KUNIT_CASE(xor_benchmark),
 	{},
 };
 
-- 
2.53.0

[PATCH 5/8] raid6: enable lock context analysis

[Christoph Hellwig]

The code doesn't have any locking, so this is trivial.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/raid6/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/raid/raid6/Makefile b/lib/raid/raid6/Makefile
index 038d6c74d1ba..5cdb7223de2a 100644
--- a/lib/raid/raid6/Makefile
+++ b/lib/raid/raid6/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
+CONTEXT_ANALYSIS := y
+
 ccflags-y			+= -I $(src)
 
 ifeq ($(CONFIG_RAID6_PQ_ARCH),y)
-- 
2.53.0

[PATCH 6/8] raid6: defer implementation selection when built-in

[Christoph Hellwig]

Don't hold up early boot and defer the selection just like we've been
doing for the RAID5 XOR code since commit 524ccdbdfb52 ("crypto: xor -
defer load time benchmark to a later time").

This will also allow full use of the timing subsystem for benchmarking.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/raid6/algos.c | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/lib/raid/raid6/algos.c b/lib/raid/raid6/algos.c
index 6f5c89ab2b17..e7984bde5157 100644
--- a/lib/raid/raid6/algos.c
+++ b/lib/raid/raid6/algos.c
@@ -236,16 +236,6 @@ static int __init raid6_select_algo(void)
 	int i, cycle;
 	int error;
 
-	if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK) || raid6_nr_algos == 1) {
-		pr_info("raid6: skipped pq benchmark and selected %s\n",
-			raid6_algos[raid6_nr_algos - 1]->name);
-		static_call_update(raid6_gen_syndrome_impl,
-				raid6_algos[raid6_nr_algos - 1]->gen_syndrome);
-		static_call_update(raid6_xor_syndrome_impl,
-				raid6_algos[raid6_nr_algos - 1]->xor_syndrome);
-		return 0;
-	}
-
 	/* prepare the buffer and fill it circularly with gfmul table */
 	disk_ptr = kmalloc(PAGE_SIZE * RAID6_TEST_DISKS, GFP_KERNEL);
 	if (!disk_ptr) {
@@ -329,13 +319,40 @@ static int __init raid6_init(void)
 	static_call_update(raid6_recov_datap_impl, raid6_recov_algo->datap);
 	pr_info("raid6: using %s recovery algorithm\n", raid6_recov_algo->name);
 
+	if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK) || raid6_nr_algos == 1) {
+		pr_info("raid6: skipped pq benchmark and selected %s\n",
+			raid6_algos[raid6_nr_algos - 1]->name);
+		goto default_algo;
+	}
+
+#ifdef MODULE
 	return raid6_select_algo();
+#else
+	/*
+	 * Pick the last registered implementation as the temporary default until
+	 * calibration happens.
+	 */
+#endif
+default_algo:
+	static_call_update(raid6_gen_syndrome_impl,
+			raid6_algos[raid6_nr_algos - 1]->gen_syndrome);
+	static_call_update(raid6_xor_syndrome_impl,
+			raid6_algos[raid6_nr_algos - 1]->xor_syndrome);
+	return 0;
 }
 
 static void __exit raid6_exit(void)
 {
 }
 
+/*
+ * When built-in we must register the default implementation before md
+ * initializes, but we don't want calibration to run that early as that
+ * would delay the boot process.
+ */
+#ifndef MODULE
+device_initcall(raid6_select_algo);
+#endif
 subsys_initcall(raid6_init);
 module_exit(raid6_exit);
 MODULE_LICENSE("GPL");
-- 
2.53.0

[PATCH 7/8] raid6: improve the runtime selection benchmark

[Christoph Hellwig]

Use plain ktime_get_ns for the timing, use 8 + 2 disks for a realistic
load, and report the throughput on the data disks as that is what
storage systems are measured on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/raid6/algos.c | 75 +++++++++++++++++++-----------------------
 1 file changed, 34 insertions(+), 41 deletions(-)

diff --git a/lib/raid/raid6/algos.c b/lib/raid/raid6/algos.c
index e7984bde5157..c44b986e319e 100644
--- a/lib/raid/raid6/algos.c
+++ b/lib/raid/raid6/algos.c
@@ -152,40 +152,39 @@ void raid6_recov_datap(int disks, size_t bytes, int faila, void **ptrs)
 }
 EXPORT_SYMBOL_GPL(raid6_recov_datap);
 
-#define RAID6_TIME_JIFFIES_LG2	4
-#define RAID6_TEST_DISKS	8
+#define BENCH_SIZE	SZ_4K
+#define NR_SRCS		8
+#define NR_DISKS	(NR_SRCS + 2)
+#define REPS		800U
 
-static int raid6_choose_gen(void *(*const dptrs)[RAID6_TEST_DISKS],
-		const int disks)
+static int raid6_choose_gen(void *dptrs[NR_DISKS], const int disks)
 {
 	/* work on the second half of the disks */
-	int start = (disks >> 1) - 1, stop = disks - 3;
+	int start = (disks / 2) - 1, stop = disks - 3;
 	const struct raid6_calls *best = NULL;
 	unsigned long bestgenperf = 0;
 	unsigned int i;
 
 	for (i = 0; i < raid6_nr_algos; i++) {
 		const struct raid6_calls *algo = raid6_algos[i];
-		unsigned long perf = 0, j0, j1;
+		unsigned long perf = 0;
+		u64 t;
+		int i;
 
 		preempt_disable();
-		j0 = jiffies;
-		while ((j1 = jiffies) == j0)
-			cpu_relax();
-		while (time_before(jiffies,
-				    j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
-			algo->gen_syndrome(disks, PAGE_SIZE, *dptrs);
-			perf++;
-		}
+		t = ktime_get_ns();
+		for (i = 0; i < REPS; i++)
+			algo->gen_syndrome(disks, BENCH_SIZE, dptrs);
+		t = ktime_get_ns() - t;
 		preempt_enable();
 
+		/* bytes/ns == GB/s, multiply by 1000 to get MB/s [not MiB/s] */
+		perf = div64_u64((u64)BENCH_SIZE * REPS * NR_SRCS * 1000, t);
 		if (perf > bestgenperf) {
 			bestgenperf = perf;
 			best = algo;
 		}
-		pr_info("raid6: %-8s gen() %5ld MB/s\n", algo->name,
-			(perf * HZ * (disks-2)) >>
-			(20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2));
+		pr_info("raid6: %-8s gen() %5lu MB/s\n", algo->name, perf);
 	}
 
 	if (!best) {
@@ -197,28 +196,22 @@ static int raid6_choose_gen(void *(*const dptrs)[RAID6_TEST_DISKS],
 	static_call_update(raid6_xor_syndrome_impl, best->xor_syndrome);
 
 	pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
-		best->name,
-		(bestgenperf * HZ * (disks - 2)) >>
-		(20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2));
+		best->name, bestgenperf);
 
 	if (best->xor_syndrome) {
-		unsigned long perf = 0, j0, j1;
+		u64 t;
+		int i;
 
 		preempt_disable();
-		j0 = jiffies;
-		while ((j1 = jiffies) == j0)
-			cpu_relax();
-		while (time_before(jiffies,
-				   j1 + (1 << RAID6_TIME_JIFFIES_LG2))) {
-			best->xor_syndrome(disks, start, stop,
-					   PAGE_SIZE, *dptrs);
-			perf++;
-		}
+		t = ktime_get_ns();
+		for (i = 0; i < REPS; i++)
+			best->xor_syndrome(disks, start, stop, BENCH_SIZE,
+				dptrs);
+		t = ktime_get_ns() - t;
 		preempt_enable();
 
-		pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n",
-			(perf * HZ * (disks - 2)) >>
-			(20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2 + 1));
+		pr_info("raid6: .... xor() %llu MB/s, rmw enabled\n",
+			div64_u64((u64)BENCH_SIZE * REPS * NR_SRCS * 1000, t));
 	}
 
 	return 0;
@@ -230,14 +223,14 @@ static int raid6_choose_gen(void *(*const dptrs)[RAID6_TEST_DISKS],
 
 static int __init raid6_select_algo(void)
 {
-	const int disks = RAID6_TEST_DISKS;
+	const int disks = NR_DISKS;
+	void *dptrs[NR_DISKS];
 	char *disk_ptr, *p;
-	void *dptrs[RAID6_TEST_DISKS];
 	int i, cycle;
 	int error;
 
 	/* prepare the buffer and fill it circularly with gfmul table */
-	disk_ptr = kmalloc(PAGE_SIZE * RAID6_TEST_DISKS, GFP_KERNEL);
+	disk_ptr = kmalloc_array(NR_DISKS, BENCH_SIZE, GFP_KERNEL);
 	if (!disk_ptr) {
 		pr_err("raid6: Yikes!  No memory available.\n");
 		return -ENOMEM;
@@ -245,19 +238,19 @@ static int __init raid6_select_algo(void)
 
 	p = disk_ptr;
 	for (i = 0; i < disks; i++)
-		dptrs[i] = p + PAGE_SIZE * i;
+		dptrs[i] = p + BENCH_SIZE * i;
 
-	cycle = ((disks - 2) * PAGE_SIZE) / 65536;
+	cycle = ((disks - 2) * BENCH_SIZE) / 65536;
 	for (i = 0; i < cycle; i++) {
 		memcpy(p, raid6_gfmul, 65536);
 		p += 65536;
 	}
 
-	if ((disks - 2) * PAGE_SIZE % 65536)
-		memcpy(p, raid6_gfmul, (disks - 2) * PAGE_SIZE % 65536);
+	if ((disks - 2) * BENCH_SIZE % 65536)
+		memcpy(p, raid6_gfmul, (disks - 2) * BENCH_SIZE % 65536);
 
 	/* select raid gen_syndrome function */
-	error = raid6_choose_gen(&dptrs, disks);
+	error = raid6_choose_gen(dptrs, disks);
 
 	kfree(disk_ptr);
 
-- 
2.53.0

[PATCH 8/8] raid6/kunit: add a benchmark

[Christoph Hellwig]

Add a benchmark to test the XOR functions for more representative block
sizes and numbers of disks.  This splits the maximum alloc size used for
the benchmark from the max size for the kunit test because recovery
is currently limited to a single page at a time.  Hopefully this will be
fixed soon.

The runtime numbers are reported in GB/s as the numbers of modern
implementations are basically unreadable as MB/s.  This means
retro-architectures could report 0, but that is an easy tradeoff.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/Kconfig                   |  9 ++++
 lib/raid/raid6/tests/raid6_kunit.c | 66 +++++++++++++++++++++++++++++-
 2 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/lib/raid/Kconfig b/lib/raid/Kconfig
index c4eeb7c716c8..c52d5c205294 100644
--- a/lib/raid/Kconfig
+++ b/lib/raid/Kconfig
@@ -60,6 +60,15 @@ config RAID6_PQ_KUNIT_TEST
 	  This is intended to help people writing architecture-specific
 	  optimized versions.  If unsure, say N.
 
+config RAID6_PQ_KUNIT_BENCHMARK
+	bool "Benchmark for RAID6 PQ"
+	depends on RAID6_PQ_KUNIT_TEST
+	help
+	  Include benchmarks in the KUnit test suite for raid P/Q generation.
+
+config RAID6_PQ
+	tristate
+
 config RAID6_PQ_BENCHMARK
 	bool "Automatically choose fastest RAID6 PQ functions"
 	depends on RAID6_PQ
diff --git a/lib/raid/raid6/tests/raid6_kunit.c b/lib/raid/raid6/tests/raid6_kunit.c
index 9f3e671a1224..f927e3456d17 100644
--- a/lib/raid/raid6/tests/raid6_kunit.c
+++ b/lib/raid/raid6/tests/raid6_kunit.c
@@ -18,6 +18,7 @@ MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
 #define RAID6_KUNIT_MAX_BUFFERS		64 /* Including P and Q */
 #define RAID6_KUNIT_MAX_FAILURES	2
 #define RAID6_KUNIT_MAX_BYTES		PAGE_SIZE
+#define RAID6_KUNIT_ALLOC_BYTES		SZ_16K
 
 static struct rnd_state rng;
 static void *test_buffers[RAID6_KUNIT_MAX_BUFFERS];
@@ -229,6 +230,68 @@ static void raid6_test(struct kunit *test)
 		raid6_test_one(test);
 }
 
+static void raid6_benchmark(struct kunit *test)
+{
+	static const unsigned int nr_to_test[] = {
+		4, 5, 6, 7, 8, 10, 12, 15, 16, 32,
+	};
+	static const unsigned int len_to_test[] = {
+		SZ_4K, SZ_16K,
+	};
+	unsigned int i, j, l;
+	u64 t;
+
+	if (!IS_ENABLED(CONFIG_RAID6_PQ_KUNIT_BENCHMARK))
+		kunit_skip(test, "not enabled");
+
+	/* warm-up */
+	for (i = 0; i < ARRAY_SIZE(nr_to_test); i++) {
+		for (j = 0; j < ARRAY_SIZE(len_to_test); j++) {
+			for (l = 0; l < 10; l++) {
+				raid6_gen_syndrome(nr_to_test[i],
+						len_to_test[j], test_buffers);
+			}
+		}
+	}
+
+	/*
+	 * Preferably this would be a loop over len_to_test, but the kunit
+	 * logging always adds a newline to each logged format string.
+	 */
+	static_assert(ARRAY_SIZE(len_to_test) == 2);
+	kunit_info(test, "          \t%5u bytes\t%5u bytes\n",
+			len_to_test[0], len_to_test[1]);
+
+	for (i = 0; i < ARRAY_SIZE(nr_to_test); i++) {
+		unsigned int nr = nr_to_test[i];
+		u64 speed[ARRAY_SIZE(len_to_test)];
+
+		KUNIT_ASSERT_LE(test, nr, RAID6_KUNIT_MAX_BUFFERS);
+
+		for (j = 0; j < ARRAY_SIZE(len_to_test); j++) {
+			unsigned int len = len_to_test[j];
+			const unsigned long num_iters = 1000;
+
+			KUNIT_ASSERT_GT(test, len, 0);
+			KUNIT_ASSERT_LE(test, len, RAID6_KUNIT_ALLOC_BYTES);
+
+			preempt_disable();
+			t = ktime_get_ns();
+			for (l = 0; l < num_iters; l++)
+				raid6_gen_syndrome(nr_to_test[i],
+						len_to_test[j], test_buffers);
+			t = ktime_get_ns() - t;
+			preempt_enable();
+
+			speed[j] = div64_u64((u64)len * num_iters * nr, t);
+		}
+
+		static_assert(ARRAY_SIZE(len_to_test) == 2);
+		kunit_info(test, "%3u disks:\t%5llu  GB/s\t%5llu  GB/s\n",
+				nr, speed[0], speed[1]);
+	}
+}
+
 static const void *raid6_gen_params(struct kunit *test, const void *prev,
 		char *desc)
 {
@@ -256,6 +319,7 @@ static const void *raid6_gen_params(struct kunit *test, const void *prev,
 
 static struct kunit_case raid6_test_cases[] = {
 	KUNIT_CASE_PARAM(raid6_test, raid6_gen_params),
+	KUNIT_CASE(raid6_benchmark),
 	{},
 };
 
@@ -270,7 +334,7 @@ static int raid6_suite_init(struct kunit_suite *suite)
 	 * so that it is immediately followed by a guard page.  This allows
 	 * buffer overreads to be detected, even in assembly code.
 	 */
-	test_buflen = round_up(RAID6_KUNIT_MAX_BYTES, PAGE_SIZE);
+	test_buflen = round_up(RAID6_KUNIT_ALLOC_BYTES, PAGE_SIZE);
 	for (i = 0; i < RAID6_KUNIT_MAX_FAILURES; i++) {
 		test_recov_buffers[i] = vmalloc(test_buflen);
 		if (!test_recov_buffers[i])
-- 
2.53.0

[PATCH 1/8] xor: enable lock context analysis

[Christoph Hellwig]

The code doesn't have any locking, so this is trivial.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/xor/Makefile       | 2 ++
 lib/raid/xor/tests/Makefile | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/lib/raid/xor/Makefile b/lib/raid/xor/Makefile
index e8ecec3c09f9..9b0fad459cdb 100644
--- a/lib/raid/xor/Makefile
+++ b/lib/raid/xor/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
+CONTEXT_ANALYSIS := y
+
 ccflags-y			+= -I $(src)
 
 obj-$(CONFIG_XOR_BLOCKS)	+= xor.o
diff --git a/lib/raid/xor/tests/Makefile b/lib/raid/xor/tests/Makefile
index 661e8f6ffd1f..1cce833cd7fd 100644
--- a/lib/raid/xor/tests/Makefile
+++ b/lib/raid/xor/tests/Makefile
@@ -1,3 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+CONTEXT_ANALYSIS := y
+
 obj-$(CONFIG_XOR_KUNIT_TEST) += xor_kunit.o
-- 
2.53.0

[PATCH 1/8] xor: enable lock context analysis

[Christoph Hellwig]

The code doesn't have any locking, so this is trivial.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/raid/xor/Makefile       | 2 ++
 lib/raid/xor/tests/Makefile | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/lib/raid/xor/Makefile b/lib/raid/xor/Makefile
index e8ecec3c09f9..9b0fad459cdb 100644
--- a/lib/raid/xor/Makefile
+++ b/lib/raid/xor/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
+CONTEXT_ANALYSIS := y
+
 ccflags-y			+= -I $(src)
 
 obj-$(CONFIG_XOR_BLOCKS)	+= xor.o
diff --git a/lib/raid/xor/tests/Makefile b/lib/raid/xor/tests/Makefile
index 661e8f6ffd1f..1cce833cd7fd 100644
--- a/lib/raid/xor/tests/Makefile
+++ b/lib/raid/xor/tests/Makefile
@@ -1,3 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+CONTEXT_ANALYSIS := y
+
 obj-$(CONFIG_XOR_KUNIT_TEST) += xor_kunit.o
-- 
2.53.0