From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id BE2AA1A0678 for ; Wed, 28 May 2014 19:27:31 +1000 (EST) Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [122.248.162.5]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 7BC3F1400D4 for ; Wed, 28 May 2014 19:27:30 +1000 (EST) Received: from /spool/local by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 28 May 2014 14:57:27 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id D54B81258054 for ; Wed, 28 May 2014 14:56:36 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s4S9RYJ852297950 for ; Wed, 28 May 2014 14:57:34 +0530 Received: from d28av05.in.ibm.com (localhost [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s4S9RNQx019490 for ; Wed, 28 May 2014 14:57:23 +0530 From: "Aneesh Kumar K.V" To: Michael Ellerman , linuxppc-dev@ozlabs.org Subject: Re: [PATCH 2/2] selftests/powerpc: Test the THP bug we fixed in the previous commit In-Reply-To: <1401265278-29307-2-git-send-email-mpe@ellerman.id.au> References: <1401265278-29307-1-git-send-email-mpe@ellerman.id.au> <1401265278-29307-2-git-send-email-mpe@ellerman.id.au> Date: Wed, 28 May 2014 14:57:23 +0530 Message-ID: <8738fumex0.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Cc: aneesh.kumar@in.ibm.com, Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Michael Ellerman writes: > Signed-off-by: Michael Ellerman Reviewed-by: Aneesh Kumar K.V > --- > 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 > +#include > +#include > + > +#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