| Message ID | 1401265278-29307-2-git-send-email-mpe@ellerman.id.au (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
Michael Ellerman <mpe@ellerman.id.au> writes: > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > --- > tools/testing/selftests/powerpc/Makefile | 2 +- > tools/testing/selftests/powerpc/mm/Makefile | 18 ++++++ > .../selftests/powerpc/mm/hugetlb_vs_thp_test.c | 72 ++++++++++++++++++++++ > 3 files changed, 91 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/powerpc/mm/Makefile > create mode 100644 tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c > > diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile > index 316194f..b3dbe9e 100644 > --- a/tools/testing/selftests/powerpc/Makefile > +++ b/tools/testing/selftests/powerpc/Makefile > @@ -13,7 +13,7 @@ CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CUR > > export CC CFLAGS > > -TARGETS = pmu copyloops > +TARGETS = pmu copyloops mm > > endif > > diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile > new file mode 100644 > index 0000000..357ccbd > --- /dev/null > +++ b/tools/testing/selftests/powerpc/mm/Makefile > @@ -0,0 +1,18 @@ > +noarg: > + $(MAKE) -C ../ > + > +PROGS := hugetlb_vs_thp_test > + > +all: $(PROGS) > + > +$(PROGS): ../harness.c > + > +run_tests: all > + @-for PROG in $(PROGS); do \ > + ./$$PROG; \ > + done; > + > +clean: > + rm -f $(PROGS) > + > +.PHONY: all run_tests clean > diff --git a/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c > new file mode 100644 > index 0000000..3d8e5b0 > --- /dev/null > +++ b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c > @@ -0,0 +1,72 @@ > +#include <stdio.h> > +#include <sys/mman.h> > +#include <unistd.h> > + > +#include "utils.h" > + > +/* This must match the huge page & THP size */ > +#define SIZE (16 * 1024 * 1024) > + > +static int test_body(void) > +{ > + void *addr; > + char *p; > + > + addr = (void *)0xa0000000; > + > + p = mmap(addr, SIZE, PROT_READ | PROT_WRITE, > + MAP_HUGETLB | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); > + if (p != MAP_FAILED) { > + /* > + * Typically the mmap will fail because no huge pages are > + * allocated on the system. But if there are huge pages > + * allocated the mmap will succeed. That's fine too, we just > + * munmap here before continuing. > + */ > + munmap(addr, SIZE); > + } > + > + p = mmap(addr, SIZE, PROT_READ | PROT_WRITE, > + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); > + if (p == MAP_FAILED) { > + printf("Mapping failed @ %p\n", addr); > + perror("mmap"); > + return 1; > + } > + > + /* > + * Either a user or kernel access is sufficient to trigger the bug. > + * A kernel access is easier to spot & debug, as it will trigger the > + * softlockup or RCU stall detectors, and when the system is kicked > + * into xmon we get a backtrace in the kernel. > + * > + * A good option is: > + * getcwd(p, SIZE); > + * > + * For the purposes of this testcase it's preferable to spin in > + * userspace, so the harness can kill us if we get stuck. That way we > + * see a test failure rather than a dead system. > + */ > + *p = 0xf; > + > + munmap(addr, SIZE); > + > + return 0; > +} > + > +static int test_main(void) > +{ > + int i; > + > + /* 10,000 because it's a "bunch", and completes reasonably quickly */ > + for (i = 0; i < 10000; i++) > + if (test_body()) > + return 1; > + > + return 0; > +} > + > +int main(void) > +{ > + return test_harness(test_main, "hugetlb_vs_thp"); > +} > -- > 1.9.1 > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev
diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile index 316194f..b3dbe9e 100644 --- a/tools/testing/selftests/powerpc/Makefile +++ b/tools/testing/selftests/powerpc/Makefile @@ -13,7 +13,7 @@ CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CUR export CC CFLAGS -TARGETS = pmu copyloops +TARGETS = pmu copyloops mm endif diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile new file mode 100644 index 0000000..357ccbd --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/Makefile @@ -0,0 +1,18 @@ +noarg: + $(MAKE) -C ../ + +PROGS := hugetlb_vs_thp_test + +all: $(PROGS) + +$(PROGS): ../harness.c + +run_tests: all + @-for PROG in $(PROGS); do \ + ./$$PROG; \ + done; + +clean: + rm -f $(PROGS) + +.PHONY: all run_tests clean diff --git a/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c new file mode 100644 index 0000000..3d8e5b0 --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c @@ -0,0 +1,72 @@ +#include <stdio.h> +#include <sys/mman.h> +#include <unistd.h> + +#include "utils.h" + +/* This must match the huge page & THP size */ +#define SIZE (16 * 1024 * 1024) + +static int test_body(void) +{ + void *addr; + char *p; + + addr = (void *)0xa0000000; + + p = mmap(addr, SIZE, PROT_READ | PROT_WRITE, + MAP_HUGETLB | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + if (p != MAP_FAILED) { + /* + * Typically the mmap will fail because no huge pages are + * allocated on the system. But if there are huge pages + * allocated the mmap will succeed. That's fine too, we just + * munmap here before continuing. + */ + munmap(addr, SIZE); + } + + p = mmap(addr, SIZE, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + if (p == MAP_FAILED) { + printf("Mapping failed @ %p\n", addr); + perror("mmap"); + return 1; + } + + /* + * Either a user or kernel access is sufficient to trigger the bug. + * A kernel access is easier to spot & debug, as it will trigger the + * softlockup or RCU stall detectors, and when the system is kicked + * into xmon we get a backtrace in the kernel. + * + * A good option is: + * getcwd(p, SIZE); + * + * For the purposes of this testcase it's preferable to spin in + * userspace, so the harness can kill us if we get stuck. That way we + * see a test failure rather than a dead system. + */ + *p = 0xf; + + munmap(addr, SIZE); + + return 0; +} + +static int test_main(void) +{ + int i; + + /* 10,000 because it's a "bunch", and completes reasonably quickly */ + for (i = 0; i < 10000; i++) + if (test_body()) + return 1; + + return 0; +} + +int main(void) +{ + return test_harness(test_main, "hugetlb_vs_thp"); +}
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- tools/testing/selftests/powerpc/Makefile | 2 +- tools/testing/selftests/powerpc/mm/Makefile | 18 ++++++ .../selftests/powerpc/mm/hugetlb_vs_thp_test.c | 72 ++++++++++++++++++++++ 3 files changed, 91 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/mm/Makefile create mode 100644 tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c