Bug #78092 [NEW]: Opcache shared lockfile and fcntl()

From: stefan dot djordjevic at humanity dot com Operating system: Centos 7.6 PHP version: Irrelevant Package: opcache Bug Type: Bug Bug description: Opcache shared lockfile and fcntl() Description: ------------ Hi, We got some strange behaviour which seems related to shared lockfile stored on a default path (/tmp/.ZendSem.04tkPY) Randomly our Apache server with forked workers enter in some strange "loop", which slows them down and brings our load and number of apache workers to max. I mange to strace them and what I see is: cntl(10, F_SETLKW, {l_type=F_WRLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 fcntl(10, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 fcntl(10, F_SETLKW, {l_type=F_WRLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 fcntl(10, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 fcntl(10, F_SETLKW, {l_type=F_WRLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 fcntl(10, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 fcntl(10, F_SETLKW, {l_type=F_WRLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 fcntl(10, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET, l_start=0, l_len=1}) = 0 . . At one point in time it just passed this "condition" and execute, finish request. File Descriptor is actually pointing to opcode lock files: ls -l /proc/30174/fd/10 lrwx------ 1 root root 64 May 30 13:35 /proc/30174/fd/10 -> /tmp/.ZendSem.04tkPY (deleted) As this condition happens pretty randomly, it's hard to identify real cause of this, but from what I see is that it entering some kind of loop, or race condition with locking - unlocking pattern. I am trying to figure out how we get to this condition, as there are many "variables" included in our new setup (docker containers etc.) I am wondering if you guys have any clue if this can be triggered by some kind of bug in Zend opcode cache-ing mechanism or similar ? Thanks. -- Edit bug report at https://bugs.php.net/bug.php?id=78092&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=78092&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=78092&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=78092&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=78092&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=78092&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=78092&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=78092&r=needscript Try newer version: https://bugs.php.net/fix.php?id=78092&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=78092&r=support Expected behavior: https://bugs.php.net/fix.php?id=78092&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=78092&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=78092&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=78092&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=78092&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=78092&r=dst IIS Stability: https://bugs.php.net/fix.php?id=78092&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=78092&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=78092&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=78092&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=78092&r=mysqlcfg