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author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2017-11-18 02:31:22 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-18 03:10:04 +0300 |
commit | 64c349f4ae78723248c474531d0cbc524fc5ba77 (patch) | |
tree | b8284ccb8224f9f4023d5b4c1caa6bc053a2c90f /tools/testing/selftests/vm | |
parent | 15df03c87983660a4d1eedb4541778592bd97684 (diff) | |
download | linux-64c349f4ae78723248c474531d0cbc524fc5ba77.tar.xz |
mm: add infrastructure for get_user_pages_fast() benchmarking
Performance of get_user_pages_fast() is critical for some workloads, but
it's tricky to test it directly.
This patch provides /sys/kernel/debug/gup_benchmark that helps with
testing performance of it.
See tools/testing/selftests/vm/gup_benchmark.c for userspace
counterpart.
Link: http://lkml.kernel.org/r/20170908215603.9189-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/testing/selftests/vm')
-rw-r--r-- | tools/testing/selftests/vm/Makefile | 1 | ||||
-rw-r--r-- | tools/testing/selftests/vm/gup_benchmark.c | 91 |
2 files changed, 92 insertions, 0 deletions
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index e49eca1915f8..7f45806bd863 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -18,6 +18,7 @@ TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd TEST_GEN_FILES += mlock-random-test TEST_GEN_FILES += virtual_address_range +TEST_GEN_FILES += gup_benchmark TEST_PROGS := run_vmtests diff --git a/tools/testing/selftests/vm/gup_benchmark.c b/tools/testing/selftests/vm/gup_benchmark.c new file mode 100644 index 000000000000..36df55132036 --- /dev/null +++ b/tools/testing/selftests/vm/gup_benchmark.c @@ -0,0 +1,91 @@ +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/prctl.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include <linux/types.h> + +#define MB (1UL << 20) +#define PAGE_SIZE sysconf(_SC_PAGESIZE) + +#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark) + +struct gup_benchmark { + __u64 delta_usec; + __u64 addr; + __u64 size; + __u32 nr_pages_per_call; + __u32 flags; +}; + +int main(int argc, char **argv) +{ + struct gup_benchmark gup; + unsigned long size = 128 * MB; + int i, fd, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0; + char *p; + + while ((opt = getopt(argc, argv, "m:r:n:tT")) != -1) { + switch (opt) { + case 'm': + size = atoi(optarg) * MB; + break; + case 'r': + repeats = atoi(optarg); + break; + case 'n': + nr_pages = atoi(optarg); + break; + case 't': + thp = 1; + break; + case 'T': + thp = 0; + break; + case 'w': + write = 1; + default: + return -1; + } + } + + gup.nr_pages_per_call = nr_pages; + gup.flags = write; + + fd = open("/sys/kernel/debug/gup_benchmark", O_RDWR); + if (fd == -1) + perror("open"), exit(1); + + p = mmap(NULL, size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + if (p == MAP_FAILED) + perror("mmap"), exit(1); + gup.addr = (unsigned long)p; + + if (thp == 1) + madvise(p, size, MADV_HUGEPAGE); + else if (thp == 0) + madvise(p, size, MADV_NOHUGEPAGE); + + for (; (unsigned long)p < gup.addr + size; p += PAGE_SIZE) + p[0] = 0; + + for (i = 0; i < repeats; i++) { + gup.size = size; + if (ioctl(fd, GUP_FAST_BENCHMARK, &gup)) + perror("ioctl"), exit(1); + + printf("Time: %lld us", gup.delta_usec); + if (gup.size != size) + printf(", truncated (size: %lld)", gup.size); + printf("\n"); + } + + return 0; +} |