| Message ID | 1438358041-18021-8-git-send-email-alex.bennee@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Fri, Jul 31, 2015 at 04:53:57PM +0100, Alex Bennée wrote: > This adds a fairly brain dead torture test for TLB flushes intended for > stressing the MTTCG QEMU build. It takes the usual -smp option for > multiple CPUs. > > By default it CPU0 will do a TLBIALL flush after each cycle. You can > pass options via -append to control additional aspects of the test: > > - "page" flush each page in turn (one per function) > - "self" do the flush after each computation cycle > - "verbose" report progress on each computation cycle > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > > --- > v2 > - rename to tlbflush-test > - made makefile changes cleaner > - added self/other flush mode > - create specific prefix > - whitespace fixes > --- > arm/tlbflush-test.c | 194 +++++++++++++++++++++++++++++++++++++++++++ > config/config-arm-common.mak | 7 +- > 2 files changed, 198 insertions(+), 3 deletions(-) > create mode 100644 arm/tlbflush-test.c > > diff --git a/arm/tlbflush-test.c b/arm/tlbflush-test.c > new file mode 100644 > index 0000000..0375ad9 > --- /dev/null > +++ b/arm/tlbflush-test.c missing GPL header > @@ -0,0 +1,194 @@ > +#include <libcflat.h> > +#include <asm/smp.h> > +#include <asm/cpumask.h> > +#include <asm/barrier.h> > +#include <asm/mmu.h> > + > +#define SEQ_LENGTH 10 > +#define SEQ_HASH 0x7cd707fe > + > +static cpumask_t smp_test_complete; > +static int flush_count = 1000000; > +static int flush_self = 0; > +static int flush_page = 0; > +static int flush_verbose = 0; nit: explicit = 0 not necessary and could use type bool > + > +/* Work functions > + * > + * These work functions need to be: > + * > + * - page aligned, so we can flush one function at a time > + * - have branches, so QEMU TCG generates multiple basic blocks > + * - call across pages, so we exercise the TCG basic block slow path > + */ nit: qemu comment style, please use kernel style (also other comments below) > + > +/* Adler32 */ > +__attribute__((aligned(PAGE_SIZE))) uint32_t hash_array(const void *buf, > + size_t buflen) > +{ > + const uint8_t *data = (uint8_t *) buf; > + uint32_t s1 = 1; > + uint32_t s2 = 0; > + > + for (size_t n = 0; n < buflen; n++) { > + s1 = (s1 + data[n]) % 65521; > + s2 = (s2 + s1) % 65521; > + } > + return (s2 << 16) | s1; > +} > + > +__attribute__((aligned(PAGE_SIZE))) void create_fib_sequence(int length, > + unsigned int *array) > +{ > + int i; > + > + /* first two values */ > + array[0] = 0; > + array[1] = 1; > + for (i=2; i<length; i++) { > + array[i] = array[i-2] + array[i-1]; > + } > +} > + > +__attribute__((aligned(PAGE_SIZE))) unsigned long long factorial(unsigned int n) > +{ > + unsigned int i; > + unsigned long long fac = 1; > + for (i=1; i<=n; i++) > + { > + fac = fac * i; > + } nit: brace style > + return fac; > +} > + > +__attribute__((aligned(PAGE_SIZE))) void factorial_array > +(unsigned int n, unsigned int *input, unsigned long long *output) > +{ > + unsigned int i; > + for (i=0; i<n; i++) { > + output[i] = factorial(input[i]); > + } > +} > + > +__attribute__((aligned(PAGE_SIZE))) unsigned int do_computation(void) > +{ > + unsigned int fib_array[SEQ_LENGTH]; > + unsigned long long facfib_array[SEQ_LENGTH]; > + uint32_t fib_hash, facfib_hash; > + > + create_fib_sequence(SEQ_LENGTH, &fib_array[0]); > + fib_hash = hash_array(&fib_array[0], sizeof(fib_array)); > + factorial_array(SEQ_LENGTH, &fib_array[0], &facfib_array[0]); > + facfib_hash = hash_array(&facfib_array[0], sizeof(facfib_array)); > + > + return (fib_hash ^ facfib_hash); > +} I still find the complex hash distracting. But if you believe it's necessary for your mttcg test, then please explain why in a comment. > + > +/* This provides a table of the work functions so we can flush each > + * page individually > + */ > +static void * pages[] = {&hash_array, &create_fib_sequence, &factorial, > + &factorial_array, &do_computation}; > + > +static void do_flush(int i) > +{ > + if (flush_page) { > + flush_tlb_page((unsigned long)pages[i % ARRAY_SIZE(pages)]); > + } else { > + flush_tlb_all(); > + } nit: no need for braces > +} > + > + > +static void just_compute(void) name it do_compute? (it's not just_compute when flush_self is true) > +{ > + int i, errors = 0; > + int cpu = smp_processor_id(); > + > + uint32_t result; > + > + printf("CPU%d online\n", cpu); > + > + for (i=0; i < flush_count; i++) { > + result = do_computation(); > + > + if (result != SEQ_HASH) { > + errors++; > + printf("CPU%d: seq%d 0x%x!=0x%x\n", > + cpu, i, result, SEQ_HASH); > + } > + > + if (flush_verbose && (i % 1000) == 0) { > + printf("CPU%d: seq%d\n", cpu, i); > + } > + > + if (flush_self) { > + do_flush(i); > + } nit: braces again (I feel like I'm reading qemu code, but with tabs :-) > + } > + > + report("CPU%d: Done - Errors: %d\n", errors == 0, cpu, errors); > + > + cpumask_set_cpu(cpu, &smp_test_complete); > + if (cpu != 0) > + halt(); > +} > + > +static void just_flush(void) > +{ > + int cpu = smp_processor_id(); > + int i = 0; > + > + /* set our CPU as done, keep flushing until everyone else > + finished */ > + cpumask_set_cpu(cpu, &smp_test_complete); > + > + while (!cpumask_full(&smp_test_complete)) { > + do_flush(i++); > + } braces > + > + report("CPU%d: Done - Triggered %d flushes\n", true, cpu, i); > +} > + > +int main(int argc, char **argv) > +{ > + int cpu, i; > + char prefix[100]; > + > + for (i=0; i<argc; i++) { > + char *arg = argv[i]; > + > + if (strcmp(arg, "page") == 0) { > + flush_page = 1; > + } strange spaces after tab before brace here > + > + if (strcmp(arg, "self") == 0) { > + flush_self = 1; > + } what happened to tabs here? > + > + if (strcmp(arg, "verbose") == 0) { > + flush_verbose = 1; > + } > + } > + > + snprintf(prefix, sizeof(prefix), "tlbflush_%s_%s", > + flush_page?"page":"all", > + flush_self?"self":"other"); > + report_prefix_push(prefix); > + > + for_each_present_cpu(cpu) { > + if (cpu == 0) > + continue; > + smp_boot_secondary(cpu, just_compute); > + } > + > + if (flush_self) > + just_compute(); > + else > + just_flush(); > + > + while (!cpumask_full(&smp_test_complete)) > + cpu_relax(); > + > + return report_summary(); > +} > diff --git a/config/config-arm-common.mak b/config/config-arm-common.mak > index 0674daa..164199b 100644 > --- a/config/config-arm-common.mak > +++ b/config/config-arm-common.mak > @@ -9,9 +9,9 @@ ifeq ($(LOADADDR),) > LOADADDR = 0x40000000 > endif > > -tests-common = \ > - $(TEST_DIR)/selftest.flat \ > - $(TEST_DIR)/spinlock-test.flat > +tests-common = $(TEST_DIR)/selftest.flat > +tests-common += $(TEST_DIR)/spinlock-test.flat > +tests-common += $(TEST_DIR)/tlbflush-test.flat > > all: test_cases > > @@ -72,3 +72,4 @@ test_cases: $(generated_files) $(tests-common) $(tests) > > $(TEST_DIR)/selftest.elf: $(cstart.o) $(TEST_DIR)/selftest.o > $(TEST_DIR)/spinlock-test.elf: $(cstart.o) $(TEST_DIR)/spinlock-test.o > +$(TEST_DIR)/tlbflush-test.elf: $(cstart.o) $(TEST_DIR)/tlbflush-test.o > -- > 2.5.0 > > Please run $KERNEL/scripts/checkpatch.pl -f on this file like I suggested before. Thanks, drew
diff --git a/arm/tlbflush-test.c b/arm/tlbflush-test.c new file mode 100644 index 0000000..0375ad9 --- /dev/null +++ b/arm/tlbflush-test.c @@ -0,0 +1,194 @@ +#include <libcflat.h> +#include <asm/smp.h> +#include <asm/cpumask.h> +#include <asm/barrier.h> +#include <asm/mmu.h> + +#define SEQ_LENGTH 10 +#define SEQ_HASH 0x7cd707fe + +static cpumask_t smp_test_complete; +static int flush_count = 1000000; +static int flush_self = 0; +static int flush_page = 0; +static int flush_verbose = 0; + +/* Work functions + * + * These work functions need to be: + * + * - page aligned, so we can flush one function at a time + * - have branches, so QEMU TCG generates multiple basic blocks + * - call across pages, so we exercise the TCG basic block slow path + */ + +/* Adler32 */ +__attribute__((aligned(PAGE_SIZE))) uint32_t hash_array(const void *buf, + size_t buflen) +{ + const uint8_t *data = (uint8_t *) buf; + uint32_t s1 = 1; + uint32_t s2 = 0; + + for (size_t n = 0; n < buflen; n++) { + s1 = (s1 + data[n]) % 65521; + s2 = (s2 + s1) % 65521; + } + return (s2 << 16) | s1; +} + +__attribute__((aligned(PAGE_SIZE))) void create_fib_sequence(int length, + unsigned int *array) +{ + int i; + + /* first two values */ + array[0] = 0; + array[1] = 1; + for (i=2; i<length; i++) { + array[i] = array[i-2] + array[i-1]; + } +} + +__attribute__((aligned(PAGE_SIZE))) unsigned long long factorial(unsigned int n) +{ + unsigned int i; + unsigned long long fac = 1; + for (i=1; i<=n; i++) + { + fac = fac * i; + } + return fac; +} + +__attribute__((aligned(PAGE_SIZE))) void factorial_array +(unsigned int n, unsigned int *input, unsigned long long *output) +{ + unsigned int i; + for (i=0; i<n; i++) { + output[i] = factorial(input[i]); + } +} + +__attribute__((aligned(PAGE_SIZE))) unsigned int do_computation(void) +{ + unsigned int fib_array[SEQ_LENGTH]; + unsigned long long facfib_array[SEQ_LENGTH]; + uint32_t fib_hash, facfib_hash; + + create_fib_sequence(SEQ_LENGTH, &fib_array[0]); + fib_hash = hash_array(&fib_array[0], sizeof(fib_array)); + factorial_array(SEQ_LENGTH, &fib_array[0], &facfib_array[0]); + facfib_hash = hash_array(&facfib_array[0], sizeof(facfib_array)); + + return (fib_hash ^ facfib_hash); +} + +/* This provides a table of the work functions so we can flush each + * page individually + */ +static void * pages[] = {&hash_array, &create_fib_sequence, &factorial, + &factorial_array, &do_computation}; + +static void do_flush(int i) +{ + if (flush_page) { + flush_tlb_page((unsigned long)pages[i % ARRAY_SIZE(pages)]); + } else { + flush_tlb_all(); + } +} + + +static void just_compute(void) +{ + int i, errors = 0; + int cpu = smp_processor_id(); + + uint32_t result; + + printf("CPU%d online\n", cpu); + + for (i=0; i < flush_count; i++) { + result = do_computation(); + + if (result != SEQ_HASH) { + errors++; + printf("CPU%d: seq%d 0x%x!=0x%x\n", + cpu, i, result, SEQ_HASH); + } + + if (flush_verbose && (i % 1000) == 0) { + printf("CPU%d: seq%d\n", cpu, i); + } + + if (flush_self) { + do_flush(i); + } + } + + report("CPU%d: Done - Errors: %d\n", errors == 0, cpu, errors); + + cpumask_set_cpu(cpu, &smp_test_complete); + if (cpu != 0) + halt(); +} + +static void just_flush(void) +{ + int cpu = smp_processor_id(); + int i = 0; + + /* set our CPU as done, keep flushing until everyone else + finished */ + cpumask_set_cpu(cpu, &smp_test_complete); + + while (!cpumask_full(&smp_test_complete)) { + do_flush(i++); + } + + report("CPU%d: Done - Triggered %d flushes\n", true, cpu, i); +} + +int main(int argc, char **argv) +{ + int cpu, i; + char prefix[100]; + + for (i=0; i<argc; i++) { + char *arg = argv[i]; + + if (strcmp(arg, "page") == 0) { + flush_page = 1; + } + + if (strcmp(arg, "self") == 0) { + flush_self = 1; + } + + if (strcmp(arg, "verbose") == 0) { + flush_verbose = 1; + } + } + + snprintf(prefix, sizeof(prefix), "tlbflush_%s_%s", + flush_page?"page":"all", + flush_self?"self":"other"); + report_prefix_push(prefix); + + for_each_present_cpu(cpu) { + if (cpu == 0) + continue; + smp_boot_secondary(cpu, just_compute); + } + + if (flush_self) + just_compute(); + else + just_flush(); + + while (!cpumask_full(&smp_test_complete)) + cpu_relax(); + + return report_summary(); +} diff --git a/config/config-arm-common.mak b/config/config-arm-common.mak index 0674daa..164199b 100644 --- a/config/config-arm-common.mak +++ b/config/config-arm-common.mak @@ -9,9 +9,9 @@ ifeq ($(LOADADDR),) LOADADDR = 0x40000000 endif -tests-common = \ - $(TEST_DIR)/selftest.flat \ - $(TEST_DIR)/spinlock-test.flat +tests-common = $(TEST_DIR)/selftest.flat +tests-common += $(TEST_DIR)/spinlock-test.flat +tests-common += $(TEST_DIR)/tlbflush-test.flat all: test_cases @@ -72,3 +72,4 @@ test_cases: $(generated_files) $(tests-common) $(tests) $(TEST_DIR)/selftest.elf: $(cstart.o) $(TEST_DIR)/selftest.o $(TEST_DIR)/spinlock-test.elf: $(cstart.o) $(TEST_DIR)/spinlock-test.o +$(TEST_DIR)/tlbflush-test.elf: $(cstart.o) $(TEST_DIR)/tlbflush-test.o
This adds a fairly brain dead torture test for TLB flushes intended for stressing the MTTCG QEMU build. It takes the usual -smp option for multiple CPUs. By default it CPU0 will do a TLBIALL flush after each cycle. You can pass options via -append to control additional aspects of the test: - "page" flush each page in turn (one per function) - "self" do the flush after each computation cycle - "verbose" report progress on each computation cycle Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- v2 - rename to tlbflush-test - made makefile changes cleaner - added self/other flush mode - create specific prefix - whitespace fixes --- arm/tlbflush-test.c | 194 +++++++++++++++++++++++++++++++++++++++++++ config/config-arm-common.mak | 7 +- 2 files changed, 198 insertions(+), 3 deletions(-) create mode 100644 arm/tlbflush-test.c