https://bugzilla.kernel.org/show_bug.cgi?id=218932 Bug ID: 218932 Summary: Serious problem with ext4 with all kernels, auto-commits do not settle to block device Product: File System Version: 2.5 Hardware: All OS: Linux Status: NEW Severity: normal Priority: P3 Component: ext4 Assignee: fs_ext4@xxxxxxxxxxxxxxxxxxxx Reporter: sirius@xxxxxxxxxxxxx Regression: No Tested in kernel 5.11, 6.1, 6.8 Some writes to ext4 (default commit=5) do not commit to block device in more than 25 seconds. How to reproduce: apt install php-cli -y Instead of iostat create io watcher, that shows real writes to block device in Mb every second: show_writes.php ================================= #!/usr/bin/php <?php if(!isset($argv[1])) die("provide device\n"); if(!($device = realpath($argv[1]))) die("can't realpath device\n"); if(!preg_match("@[^/]+$@", $device, $m)) die(); $device = $m[0]; $prev = 0; while(1) { $data = preg_split("/\s+/", trim(file_get_contents("/sys/block/$device/stat"))); if(empty($data)) die("can't get device info"); if($prev) echo date("h:i:s")." ".number_format(($data[6]-$prev)*512/1024/1024,2)." M\n"; $prev = $data[6]; sleep(1); } ================================= Add free HDD/partition of 20Mb+ size (/dev/vdb) In first console run: php show_writes.php /dev/vdb In second console run: mkfs.ext4 -E lazy_itable_init=0 -E lazy_journal_init=0 /dev/vdb mount /dev/vdb /mnt/ rm -f /mnt/test; sync; sleep 1; date && dd if=/dev/urandom of=/mnt/test bs=1M count=10 # watch that 10Mb write has settled in 5 seconds, good rm -f /mnt/test; sync; sleep 1; date && dd if=/dev/urandom of=/mnt/test bs=1M count=10 # watch, that second 10Mb write does not commit to block device in more than 25 seconds, but should in 5 seconds, repeat if did. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
