When running the mincore_selftest on a system with an XFS file system, it failed the "check_file_mmap" test case due to the read-ahead pages reaching the end of the file. The failure log is as below:
RUN global.check_file_mmap ... mincore_selftest.c:264:check_file_mmap:Expected i (1024) < vec_size (1024) mincore_selftest.c:265:check_file_mmap:Read-ahead pages reached the end of the file check_file_mmap: Test failed FAIL global.check_file_mmap
This is because the read-ahead window size of the XFS file system on this machine is 4 MB, which is larger than the size from the #PF address to the end of the file. As a result, all the pages for this file are populated.
blockdev --getra /dev/nvme0n1p5 8192 blockdev --getbsz /dev/nvme0n1p5 512
This issue can be fixed by extending the current FILE_SIZE 4MB to a larger number, but it will still fail if the read-ahead window size of the file system is larger enough. Additionally, in the real world, read-ahead pages reaching the end of the file can happen and is an expected behavior. Therefore, allowing read-ahead pages to reach the end of the file is a better choice for the "check_file_mmap" test case.
Reported-by: Yi Lai yi1.lai@intel.com Signed-off-by: Qiuxu Zhuo qiuxu.zhuo@intel.com --- tools/testing/selftests/mincore/mincore_selftest.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/tools/testing/selftests/mincore/mincore_selftest.c b/tools/testing/selftests/mincore/mincore_selftest.c index e949a43a6145..efabfcbe0b49 100644 --- a/tools/testing/selftests/mincore/mincore_selftest.c +++ b/tools/testing/selftests/mincore/mincore_selftest.c @@ -261,9 +261,6 @@ TEST(check_file_mmap) TH_LOG("No read-ahead pages found in memory"); }
- EXPECT_LT(i, vec_size) { - TH_LOG("Read-ahead pages reached the end of the file"); - } /* * End of the readahead window. The rest of the pages shouldn't * be in memory.