diff mbox series

[kvm-unit-tests,v2,2/2] s390x: add exittime tests

Message ID 20220901150956.1075828-3-nrb@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390x: Add exit time test | expand

Commit Message

Nico Boehr Sept. 1, 2022, 3:09 p.m. UTC 
Add a test to measure the execution time of several instructions. This
can be helpful in finding performance regressions in hypervisor code.

All tests are currently reported as PASS, since the baseline for their
execution time depends on the respective environment and since needs to
be determined on a case-by-case basis.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
---
 s390x/Makefile      |   1 +
 s390x/exittime.c    | 255 ++++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg |   4 +
 3 files changed, 260 insertions(+)
 create mode 100644 s390x/exittime.c

Comments

Claudio Imbrenda Oct. 6, 2022, 11:15 a.m. UTC | #1 
On Thu,  1 Sep 2022 17:09:56 +0200
Nico Boehr <nrb@linux.ibm.com> wrote:

> Add a test to measure the execution time of several instructions. This
> can be helpful in finding performance regressions in hypervisor code.
> 
> All tests are currently reported as PASS, since the baseline for their
> execution time depends on the respective environment and since needs to
> be determined on a case-by-case basis.
> 
> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> ---
>  s390x/Makefile      |   1 +
>  s390x/exittime.c    | 255 ++++++++++++++++++++++++++++++++++++++++++++
>  s390x/unittests.cfg |   4 +
>  3 files changed, 260 insertions(+)
>  create mode 100644 s390x/exittime.c
> 
> diff --git a/s390x/Makefile b/s390x/Makefile
> index efd5e0c13102..5dcac244767f 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -34,6 +34,7 @@ tests += $(TEST_DIR)/migration.elf
>  tests += $(TEST_DIR)/pv-attest.elf
>  tests += $(TEST_DIR)/migration-cmm.elf
>  tests += $(TEST_DIR)/migration-skey.elf
> +tests += $(TEST_DIR)/exittime.elf
>  
>  pv-tests += $(TEST_DIR)/pv-diags.elf
>  
> diff --git a/s390x/exittime.c b/s390x/exittime.c
> new file mode 100644
> index 000000000000..543c82ff3906
> --- /dev/null
> +++ b/s390x/exittime.c
> @@ -0,0 +1,255 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Measure run time of various instructions. Can be used to find runtime
> + * regressions of instructions which cause exits.
> + *
> + * Copyright IBM Corp. 2022
> + *
> + * Authors:
> + *  Nico Boehr <nrb@linux.ibm.com>
> + */
> +#include <libcflat.h>
> +#include <smp.h>
> +#include <sclp.h>
> +#include <asm/time.h>
> +#include <asm/sigp.h>
> +#include <asm/interrupt.h>
> +#include <asm/page.h>
> +
> +char pagebuf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
> +
> +static void test_sigp_sense_running(long destcpu)
> +{
> +	smp_sigp(destcpu, SIGP_SENSE_RUNNING, 0, NULL);
> +}
> +
> +static void test_nop(long ignore)
> +{
> +	/* nops don't trap into the hypervisor, so let's test them for reference */
> +	asm volatile("nop" : : : "memory");
> +}
> +
> +static void test_diag9c(long destcpu)
> +{
> +	asm volatile("diag %[destcpu],0,0x9c"
> +		:
> +		: [destcpu] "d" (destcpu)
> +		:

here you leave some unused :

> +	);
> +}
> +
> +static long setup_get_this_cpuaddr(long ignore)
> +{
> +	return stap();
> +}
> +
> +static void test_diag44(long ignore)
> +{
> +	asm volatile("diag 0,0,0x44");
> +}
> +
> +static void test_stnsm(long ignore)
> +{
> +	int out;
> +
> +	asm volatile(
> +		"stnsm %[out],0xff"
> +		: [out] "=Q" (out)
> +		:

here too, but you are using only 2

> +	);
> +}
> +
> +static void test_stosm(long ignore)
> +{
> +	int out;
> +
> +	asm volatile(
> +		"stosm %[out],0"
> +		: [out] "=Q" (out)
> +		:
> +	);
> +}
> +
> +static long setup_ssm(long ignore)
> +{
> +	long system_mask = 0;
> +
> +	asm volatile(
> +		"stosm %[system_mask],0"
> +		: [system_mask] "=Q" (system_mask)
> +		:
> +		:
> +	);
> +
> +	return system_mask;
> +}
> +
> +static void test_ssm(long old_system_mask)
> +{
> +	asm volatile(
> +		"ssm %[old_system_mask]"
> +		:
> +		: [old_system_mask] "Q" (old_system_mask)
> +		:
> +	);
> +}
> +
> +static long setup_lctl4(long ignore)
> +{
> +	long ctl4_orig = 0;
> +
> +	asm volatile(
> +		"stctg 4,4,%[ctl4_orig]"
> +		: [ctl4_orig] "=S" (ctl4_orig)
> +		:
> +		:
> +	);
> +
> +	return ctl4_orig;
> +}
> +
> +static void test_lctl4(long ctl4_orig)
> +{
> +	asm volatile(
> +		"lctlg 4,4,%[ctl4_orig]"
> +		:
> +		: [ctl4_orig] "S" (ctl4_orig)
> +		:
> +	);
> +}
> +
> +static void test_stpx(long ignore)
> +{
> +	unsigned int prefix;
> +
> +	asm volatile(
> +		"stpx %[prefix]"
> +		: [prefix] "=Q" (prefix)

here you are only using the : you actually need

> +	);
> +}
> +
> +static void test_stfl(long ignore)
> +{
> +	asm volatile(
> +		"stfl 0" : : : "memory"
> +	);
> +}
> +
> +static void test_epsw(long ignore)
> +{
> +	long r1, r2;
> +
> +	asm volatile(
> +		"epsw %[r1], %[r2]"
> +		: [r1] "=d" (r1), [r2] "=d" (r2)
> +		:
> +		:
> +	);
> +}
> +
> +static void test_illegal(long ignore)
> +{
> +	expect_pgm_int();
> +	asm volatile(
> +		".word 0"
> +		:
> +		:
> +		:

here none are needed

> +	);
> +	clear_pgm_int();
> +}

decide how you want to do for the : and then do it uniformly.

either you always put all three : (except when none are needed), or you
always only put as many as needed, without empty trailing ones.

> +
> +static long setup_servc(long arg)
> +{
> +	memset(pagebuf, 0, PAGE_SIZE);
> +	return arg;
> +}
> +
> +static void test_servc(long ignore)
> +{
> +	SCCB *sccb = (SCCB *) pagebuf;
> +
> +	sccb->h.length = 8;
> +	servc(0, (unsigned long) sccb);
> +}
> +
> +static void test_stsi(long fc)
> +{
> +	stsi(pagebuf, fc, 2, 2);
> +}
> +
> +struct test {
> +	const char *name;
> +	/*
> +	 * When non-null, will be called once before running the test loop.
> +	 * Its return value will be given as argument to testfunc.
> +	 */
> +	long (*setupfunc)(long arg);
> +	void (*testfunc)(long arg);
> +	long arg;
> +	long iters;
> +} const exittime_tests[] = {
> +	{"nop",                   NULL,                   test_nop,                0, 200000 },
> +	{"sigp sense running(0)", NULL,                   test_sigp_sense_running, 0, 20000 },
> +	{"sigp sense running(1)", NULL,                   test_sigp_sense_running, 1, 20000 },
> +	{"diag9c(self)",          setup_get_this_cpuaddr, test_diag9c,             0, 2000 },
> +	{"diag9c(0)",             NULL,                   test_diag9c,             0, 2000 },
> +	{"diag9c(1)",             NULL,                   test_diag9c,             1, 2000 },
> +	{"diag44",                NULL,                   test_diag44,             0, 2000 },
> +	{"stnsm",                 NULL,                   test_stnsm,              0, 200000 },
> +	{"stosm",                 NULL,                   test_stosm,              0, 200000 },
> +	{"ssm",                   setup_ssm,              test_ssm,                0, 200000 },
> +	{"lctl4",                 setup_lctl4,            test_lctl4,              0, 20000 },
> +	{"stpx",                  NULL,                   test_stpx,               0, 2000 },
> +	{"stfl",                  NULL,                   test_stfl,               0, 2000 },
> +	{"epsw",                  NULL,                   test_epsw,               0, 20000 },
> +	{"illegal",               NULL,                   test_illegal,            0, 2000 },
> +	{"servc",                 setup_servc,            test_servc,              0, 2000 },
> +	{"stsi122",               NULL,                   test_stsi,               1, 200 },
> +	{"stsi222",               NULL,                   test_stsi,               2, 200 },
> +	{"stsi322",               NULL,                   test_stsi,               3, 200 },
> +};
> +
> +static uint64_t tod_to_us(uint64_t tod)
> +{
> +	return tod >> STCK_SHIFT_US;
> +}
> +
> +int main(void)
> +{
> +	int i, j, k, testfunc_arg;
> +	const int outer_iters = 100;
> +	struct test const *current_test;
> +	uint64_t start, end, elapsed, worst, best, total;
> +
> +	report_prefix_push("exittime");
> +	report_pass("reporting total/best/worst of %d outer iterations", outer_iters);
> +
> +	for (i = 0; i < ARRAY_SIZE(exittime_tests); i++) {
> +		current_test = &exittime_tests[i];
> +		total = 0;
> +		worst = 0;
> +		best = -1;
> +		report_prefix_pushf("%s", current_test->name);
> +
> +		testfunc_arg = current_test->arg;
> +		if (current_test->setupfunc)
> +			testfunc_arg = current_test->setupfunc(testfunc_arg);
> +
> +		for (j = 0; j < outer_iters; j++) {
> +			start = get_clock_fast();
> +			for (k = 0; k < current_test->iters; k++)
> +				current_test->testfunc(testfunc_arg);
> +			end = get_clock_fast();
> +			elapsed = end - start;
> +			best = MIN(best, elapsed);
> +			worst = MAX(worst, elapsed);
> +			total += elapsed;
> +		}
> +		report_pass("iters/total/best/worst %lu/%lu/%lu/%lu us", current_test->iters, tod_to_us(total), tod_to_us(best), tod_to_us(worst));

perhaps it would not be a bad idea to also print the average and the
standard deviation (σ)

> +		report_prefix_pop();
> +	}
> +
> +	report_prefix_pop();
> +	return report_summary();
> +}
> diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
> index f7b1fc3dbca1..c11d1d987c82 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -185,3 +185,7 @@ groups = migration
>  [migration-skey]
>  file = migration-skey.elf
>  groups = migration
> +
> +[exittime]
> +file = exittime.elf
> +smp = 2
diff mbox series

Patch

diff --git a/s390x/Makefile b/s390x/Makefile
index efd5e0c13102..5dcac244767f 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -34,6 +34,7 @@  tests += $(TEST_DIR)/migration.elf
 tests += $(TEST_DIR)/pv-attest.elf
 tests += $(TEST_DIR)/migration-cmm.elf
 tests += $(TEST_DIR)/migration-skey.elf
+tests += $(TEST_DIR)/exittime.elf
 
 pv-tests += $(TEST_DIR)/pv-diags.elf
 
diff --git a/s390x/exittime.c b/s390x/exittime.c
new file mode 100644
index 000000000000..543c82ff3906
--- /dev/null
+++ b/s390x/exittime.c
@@ -0,0 +1,255 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Measure run time of various instructions. Can be used to find runtime
+ * regressions of instructions which cause exits.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ *  Nico Boehr <nrb@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <smp.h>
+#include <sclp.h>
+#include <asm/time.h>
+#include <asm/sigp.h>
+#include <asm/interrupt.h>
+#include <asm/page.h>
+
+char pagebuf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+
+static void test_sigp_sense_running(long destcpu)
+{
+	smp_sigp(destcpu, SIGP_SENSE_RUNNING, 0, NULL);
+}
+
+static void test_nop(long ignore)
+{
+	/* nops don't trap into the hypervisor, so let's test them for reference */
+	asm volatile("nop" : : : "memory");
+}
+
+static void test_diag9c(long destcpu)
+{
+	asm volatile("diag %[destcpu],0,0x9c"
+		:
+		: [destcpu] "d" (destcpu)
+		:
+	);
+}
+
+static long setup_get_this_cpuaddr(long ignore)
+{
+	return stap();
+}
+
+static void test_diag44(long ignore)
+{
+	asm volatile("diag 0,0,0x44");
+}
+
+static void test_stnsm(long ignore)
+{
+	int out;
+
+	asm volatile(
+		"stnsm %[out],0xff"
+		: [out] "=Q" (out)
+		:
+	);
+}
+
+static void test_stosm(long ignore)
+{
+	int out;
+
+	asm volatile(
+		"stosm %[out],0"
+		: [out] "=Q" (out)
+		:
+	);
+}
+
+static long setup_ssm(long ignore)
+{
+	long system_mask = 0;
+
+	asm volatile(
+		"stosm %[system_mask],0"
+		: [system_mask] "=Q" (system_mask)
+		:
+		:
+	);
+
+	return system_mask;
+}
+
+static void test_ssm(long old_system_mask)
+{
+	asm volatile(
+		"ssm %[old_system_mask]"
+		:
+		: [old_system_mask] "Q" (old_system_mask)
+		:
+	);
+}
+
+static long setup_lctl4(long ignore)
+{
+	long ctl4_orig = 0;
+
+	asm volatile(
+		"stctg 4,4,%[ctl4_orig]"
+		: [ctl4_orig] "=S" (ctl4_orig)
+		:
+		:
+	);
+
+	return ctl4_orig;
+}
+
+static void test_lctl4(long ctl4_orig)
+{
+	asm volatile(
+		"lctlg 4,4,%[ctl4_orig]"
+		:
+		: [ctl4_orig] "S" (ctl4_orig)
+		:
+	);
+}
+
+static void test_stpx(long ignore)
+{
+	unsigned int prefix;
+
+	asm volatile(
+		"stpx %[prefix]"
+		: [prefix] "=Q" (prefix)
+	);
+}
+
+static void test_stfl(long ignore)
+{
+	asm volatile(
+		"stfl 0" : : : "memory"
+	);
+}
+
+static void test_epsw(long ignore)
+{
+	long r1, r2;
+
+	asm volatile(
+		"epsw %[r1], %[r2]"
+		: [r1] "=d" (r1), [r2] "=d" (r2)
+		:
+		:
+	);
+}
+
+static void test_illegal(long ignore)
+{
+	expect_pgm_int();
+	asm volatile(
+		".word 0"
+		:
+		:
+		:
+	);
+	clear_pgm_int();
+}
+
+static long setup_servc(long arg)
+{
+	memset(pagebuf, 0, PAGE_SIZE);
+	return arg;
+}
+
+static void test_servc(long ignore)
+{
+	SCCB *sccb = (SCCB *) pagebuf;
+
+	sccb->h.length = 8;
+	servc(0, (unsigned long) sccb);
+}
+
+static void test_stsi(long fc)
+{
+	stsi(pagebuf, fc, 2, 2);
+}
+
+struct test {
+	const char *name;
+	/*
+	 * When non-null, will be called once before running the test loop.
+	 * Its return value will be given as argument to testfunc.
+	 */
+	long (*setupfunc)(long arg);
+	void (*testfunc)(long arg);
+	long arg;
+	long iters;
+} const exittime_tests[] = {
+	{"nop",                   NULL,                   test_nop,                0, 200000 },
+	{"sigp sense running(0)", NULL,                   test_sigp_sense_running, 0, 20000 },
+	{"sigp sense running(1)", NULL,                   test_sigp_sense_running, 1, 20000 },
+	{"diag9c(self)",          setup_get_this_cpuaddr, test_diag9c,             0, 2000 },
+	{"diag9c(0)",             NULL,                   test_diag9c,             0, 2000 },
+	{"diag9c(1)",             NULL,                   test_diag9c,             1, 2000 },
+	{"diag44",                NULL,                   test_diag44,             0, 2000 },
+	{"stnsm",                 NULL,                   test_stnsm,              0, 200000 },
+	{"stosm",                 NULL,                   test_stosm,              0, 200000 },
+	{"ssm",                   setup_ssm,              test_ssm,                0, 200000 },
+	{"lctl4",                 setup_lctl4,            test_lctl4,              0, 20000 },
+	{"stpx",                  NULL,                   test_stpx,               0, 2000 },
+	{"stfl",                  NULL,                   test_stfl,               0, 2000 },
+	{"epsw",                  NULL,                   test_epsw,               0, 20000 },
+	{"illegal",               NULL,                   test_illegal,            0, 2000 },
+	{"servc",                 setup_servc,            test_servc,              0, 2000 },
+	{"stsi122",               NULL,                   test_stsi,               1, 200 },
+	{"stsi222",               NULL,                   test_stsi,               2, 200 },
+	{"stsi322",               NULL,                   test_stsi,               3, 200 },
+};
+
+static uint64_t tod_to_us(uint64_t tod)
+{
+	return tod >> STCK_SHIFT_US;
+}
+
+int main(void)
+{
+	int i, j, k, testfunc_arg;
+	const int outer_iters = 100;
+	struct test const *current_test;
+	uint64_t start, end, elapsed, worst, best, total;
+
+	report_prefix_push("exittime");
+	report_pass("reporting total/best/worst of %d outer iterations", outer_iters);
+
+	for (i = 0; i < ARRAY_SIZE(exittime_tests); i++) {
+		current_test = &exittime_tests[i];
+		total = 0;
+		worst = 0;
+		best = -1;
+		report_prefix_pushf("%s", current_test->name);
+
+		testfunc_arg = current_test->arg;
+		if (current_test->setupfunc)
+			testfunc_arg = current_test->setupfunc(testfunc_arg);
+
+		for (j = 0; j < outer_iters; j++) {
+			start = get_clock_fast();
+			for (k = 0; k < current_test->iters; k++)
+				current_test->testfunc(testfunc_arg);
+			end = get_clock_fast();
+			elapsed = end - start;
+			best = MIN(best, elapsed);
+			worst = MAX(worst, elapsed);
+			total += elapsed;
+		}
+		report_pass("iters/total/best/worst %lu/%lu/%lu/%lu us", current_test->iters, tod_to_us(total), tod_to_us(best), tod_to_us(worst));
+		report_prefix_pop();
+	}
+
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index f7b1fc3dbca1..c11d1d987c82 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -185,3 +185,7 @@  groups = migration
 [migration-skey]
 file = migration-skey.elf
 groups = migration
+
+[exittime]
+file = exittime.elf
+smp = 2