ping...
On 4/3/21 2:38 PM, Jeffle Xu wrote:
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 size could be as large as twice the io_opt, and thus the hardcoded file size no longer works. check_file_mmap() may report "Read-ahead pages reached the end of the file" when the readahead size actually exceeds the file size in this case.
Signed-off-by: Jeffle Xu jefflexu@linux.alibaba.com
chnages since v1:
- add the test name "mincore" in the subject line
- add the error message in commit message
- rename @filesize to @file_size to keep a more consistent naming convention
.../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..3ca542934080 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, file_size;
- 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 file_size large enough to contain the readahead window.*/- ra_size *= 512;
- file_size = ra_size * 2;
page_size = sysconf(_SC_PAGESIZE);
- vec_size = FILE_SIZE / page_size;
- if (FILE_SIZE % page_size)
- vec_size = file_size / page_size;
- if (file_size % 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, file_size); 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, file_size, 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, file_size, 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[file_size / 2] = 1;
- retval = mincore(addr, file_size, vec); ASSERT_EQ(0, retval);
- ASSERT_EQ(1, vec[FILE_SIZE / 2 / page_size]) {
- ASSERT_EQ(1, vec[file_size / 2 / page_size]) { TH_LOG("Page not found in memory after use"); }
- i = FILE_SIZE / 2 / page_size + 1;
- i = file_size / 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, file_size); close(fd); free(vec);
}