The readahead size used to be 2MB, thus it's reasonable to set the file size as 4MB when checking check_file_mmap().
However since commit c2e4cd57cfa1 ("block: lift setting the readahead size into the block layer"), readahead could be as large as twice the io_opt, and thus the hardcoded file size no longer works.
Signed-off-by: Jeffle Xu jefflexu@linux.alibaba.com --- .../selftests/mincore/mincore_selftest.c | 57 +++++++++++++++---- 1 file changed, 47 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/mincore/mincore_selftest.c b/tools/testing/selftests/mincore/mincore_selftest.c index 5a1e85ff5d32..cf0c86697403 100644 --- a/tools/testing/selftests/mincore/mincore_selftest.c +++ b/tools/testing/selftests/mincore/mincore_selftest.c @@ -15,6 +15,11 @@ #include <string.h> #include <fcntl.h> #include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <sys/sysmacros.h> +#include <sys/mount.h>
#include "../kselftest.h" #include "../kselftest_harness.h" @@ -195,10 +200,42 @@ TEST(check_file_mmap) int fd; int i; int ra_pages = 0; + long ra_size, filesize; + struct stat stats; + dev_t devt; + unsigned int major, minor; + char devpath[32]; + + retval = stat(".", &stats); + ASSERT_EQ(0, retval) { + TH_LOG("Can't stat pwd: %s", strerror(errno)); + } + + devt = stats.st_dev; + major = major(devt); + minor = minor(devt); + snprintf(devpath, sizeof(devpath), "/dev/block/%u:%u", major, minor); + + fd = open(devpath, O_RDONLY); + ASSERT_NE(-1, fd) { + TH_LOG("Can't open underlying disk %s", strerror(errno)); + } + + retval = ioctl(fd, BLKRAGET, &ra_size); + ASSERT_EQ(0, retval) { + TH_LOG("Error ioctl with the underlying disk: %s", strerror(errno)); + } + + /* + * BLKRAGET ioctl returns the readahead size in sectors (512 bytes). + * Make filesize large enough to contain the readahead window. + */ + ra_size *= 512; + filesize = ra_size * 2;
page_size = sysconf(_SC_PAGESIZE); - vec_size = FILE_SIZE / page_size; - if (FILE_SIZE % page_size) + vec_size = filesize / page_size; + if (filesize % page_size) vec_size++;
vec = calloc(vec_size, sizeof(unsigned char)); @@ -213,7 +250,7 @@ TEST(check_file_mmap) strerror(errno)); } errno = 0; - retval = fallocate(fd, 0, 0, FILE_SIZE); + retval = fallocate(fd, 0, 0, filesize); ASSERT_EQ(0, retval) { TH_LOG("Error allocating space for the temporary file: %s", strerror(errno)); @@ -223,12 +260,12 @@ TEST(check_file_mmap) * Map the whole file, the pages shouldn't be fetched yet. */ errno = 0; - addr = mmap(NULL, FILE_SIZE, PROT_READ | PROT_WRITE, + addr = mmap(NULL, filesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); ASSERT_NE(MAP_FAILED, addr) { TH_LOG("mmap error: %s", strerror(errno)); } - retval = mincore(addr, FILE_SIZE, vec); + retval = mincore(addr, filesize, vec); ASSERT_EQ(0, retval); for (i = 0; i < vec_size; i++) { ASSERT_EQ(0, vec[i]) { @@ -240,14 +277,14 @@ TEST(check_file_mmap) * Touch a page in the middle of the mapping. We expect the next * few pages (the readahead window) to be populated too. */ - addr[FILE_SIZE / 2] = 1; - retval = mincore(addr, FILE_SIZE, vec); + addr[filesize / 2] = 1; + retval = mincore(addr, filesize, vec); ASSERT_EQ(0, retval); - ASSERT_EQ(1, vec[FILE_SIZE / 2 / page_size]) { + ASSERT_EQ(1, vec[filesize / 2 / page_size]) { TH_LOG("Page not found in memory after use"); }
- i = FILE_SIZE / 2 / page_size + 1; + i = filesize / 2 / page_size + 1; while (i < vec_size && vec[i]) { ra_pages++; i++; @@ -271,7 +308,7 @@ TEST(check_file_mmap) } }
- munmap(addr, FILE_SIZE); + munmap(addr, filesize); close(fd); free(vec); }