| Message ID | 20210403063800.56278-1-jefflexu@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] selftests/mincore: get readahead size for check_file_mmap() | expand |
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); > } >
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); }
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(-)