From 58c7be84fec87b3a96964d65129b36c0e8c59a19 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Tue, 30 Apr 2013 15:27:06 -0700 Subject: selftest: add simple test for soft-dirty bit It creates a mapping of 3 pages and checks that reads, writes and clear-refs result in present and soft-dirt bits reported from pagemap2 set as expected. [akpm@linux-foundation.org: alphasort the Makefile TARGETS to reduce rejects] Signed-off-by: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/selftests/Makefile | 7 +- tools/testing/selftests/soft-dirty/Makefile | 10 +++ tools/testing/selftests/soft-dirty/soft-dirty.c | 114 ++++++++++++++++++++++++ 3 files changed, 128 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/soft-dirty/Makefile create mode 100644 tools/testing/selftests/soft-dirty/soft-dirty.c (limited to 'tools') diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 3cc0ad7ae86..5eff5f785b3 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -1,10 +1,11 @@ TARGETS = breakpoints +TARGETS += cpu-hotplug +TARGETS += efivarfs TARGETS += kcmp +TARGETS += memory-hotplug TARGETS += mqueue +TARGETS += soft-dirty TARGETS += vm -TARGETS += cpu-hotplug -TARGETS += memory-hotplug -TARGETS += efivarfs all: for TARGET in $(TARGETS); do \ diff --git a/tools/testing/selftests/soft-dirty/Makefile b/tools/testing/selftests/soft-dirty/Makefile new file mode 100644 index 00000000000..a9cdc823d6e --- /dev/null +++ b/tools/testing/selftests/soft-dirty/Makefile @@ -0,0 +1,10 @@ +CFLAGS += -iquote../../../../include/uapi -Wall +soft-dirty: soft-dirty.c + +all: soft-dirty + +clean: + rm -f soft-dirty + +run_tests: all + @./soft-dirty || echo "soft-dirty selftests: [FAIL]" diff --git a/tools/testing/selftests/soft-dirty/soft-dirty.c b/tools/testing/selftests/soft-dirty/soft-dirty.c new file mode 100644 index 00000000000..aba4f87f87f --- /dev/null +++ b/tools/testing/selftests/soft-dirty/soft-dirty.c @@ -0,0 +1,114 @@ +#include +#include +#include +#include +#include +#include + +typedef unsigned long long u64; + +#define PME_PRESENT (1ULL << 63) +#define PME_SOFT_DIRTY (1Ull << 55) + +#define PAGES_TO_TEST 3 +#ifndef PAGE_SIZE +#define PAGE_SIZE 4096 +#endif + +static void get_pagemap2(char *mem, u64 *map) +{ + int fd; + + fd = open("/proc/self/pagemap2", O_RDONLY); + if (fd < 0) { + perror("Can't open pagemap2"); + exit(1); + } + + lseek(fd, (unsigned long)mem / PAGE_SIZE * sizeof(u64), SEEK_SET); + read(fd, map, sizeof(u64) * PAGES_TO_TEST); + close(fd); +} + +static inline char map_p(u64 map) +{ + return map & PME_PRESENT ? 'p' : '-'; +} + +static inline char map_sd(u64 map) +{ + return map & PME_SOFT_DIRTY ? 'd' : '-'; +} + +static int check_pte(int step, int page, u64 *map, u64 want) +{ + if ((map[page] & want) != want) { + printf("Step %d Page %d has %c%c, want %c%c\n", + step, page, + map_p(map[page]), map_sd(map[page]), + map_p(want), map_sd(want)); + return 1; + } + + return 0; +} + +static void clear_refs(void) +{ + int fd; + char *v = "4"; + + fd = open("/proc/self/clear_refs", O_WRONLY); + if (write(fd, v, 3) < 3) { + perror("Can't clear soft-dirty bit"); + exit(1); + } + close(fd); +} + +int main(void) +{ + char *mem, x; + u64 map[PAGES_TO_TEST]; + + mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE, + PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0, 0); + + x = mem[0]; + mem[2 * PAGE_SIZE] = 'c'; + get_pagemap2(mem, map); + + if (check_pte(1, 0, map, PME_PRESENT)) + return 1; + if (check_pte(1, 1, map, 0)) + return 1; + if (check_pte(1, 2, map, PME_PRESENT | PME_SOFT_DIRTY)) + return 1; + + clear_refs(); + get_pagemap2(mem, map); + + if (check_pte(2, 0, map, PME_PRESENT)) + return 1; + if (check_pte(2, 1, map, 0)) + return 1; + if (check_pte(2, 2, map, PME_PRESENT)) + return 1; + + mem[0] = 'a'; + mem[PAGE_SIZE] = 'b'; + x = mem[2 * PAGE_SIZE]; + get_pagemap2(mem, map); + + if (check_pte(3, 0, map, PME_PRESENT | PME_SOFT_DIRTY)) + return 1; + if (check_pte(3, 1, map, PME_PRESENT | PME_SOFT_DIRTY)) + return 1; + if (check_pte(3, 2, map, PME_PRESENT)) + return 1; + + (void)x; /* gcc warn */ + + printf("PASS\n"); + return 0; +} -- cgit v1.2.3