From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: fio newer than 2.2.12 segfaults on examples/tiobench-example.fio References: <569B9F48.3010808@cran.org.uk> <569D5FB4.6050602@kernel.dk> From: Bruce Cran Message-ID: <56A05EDC.4030309@cran.org.uk> Date: Wed, 20 Jan 2016 21:30:20 -0700 MIME-Version: 1.0 In-Reply-To: <569D5FB4.6050602@kernel.dk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: Jens Axboe , fio@vger.kernel.org List-ID: On 01/18/2016 02:57 PM, Jens Axboe wrote: > Can you compile with with --disable-optimizations passed to configure, > ensure that a core file is dumped (ulimit -c1000000000000 or > whatever), and then run gdb ./fio core to show a full backtrace? > > I can't reproduce the crash with 2.3 or current -git, runs fine for me. > I'm wondering if this is a microcode bug, since I have one of the new Skylake CPUs (Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz; stepping: 3; microcode: 0x6a) and others have mentioned crashes in __lll_unlock_elision related to broken CPUs/BIOSes, though for older generations. Anyway, here's the output and backtrace: (gdb) run examples/tiobench-example.fio Starting program: /home/bcran/workspace/fio/fio examples/tiobench-example.fio [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". f1: (g=0): rw=write, bs=4K-4K/4K-4K/4K-4K, ioengine=sync, iodepth=1 ... f2: (g=1): rw=randwrite, bs=4K-4K/4K-4K/4K-4K, ioengine=sync, iodepth=1 ... f3: (g=2): rw=read, bs=4K-4K/4K-4K/4K-4K, ioengine=sync, iodepth=1 ... f4: (g=3): rw=randread, bs=4K-4K/4K-4K/4K-4K, ioengine=sync, iodepth=1 ... fio-2.4-1-g44ac Starting 16 processes Detaching after fork from child process 26797. [New Thread 0x7fffe7d53700 (LWP 26796)] Program received signal SIGSEGV, Segmentation fault. __lll_unlock_elision (lock=0x7ffff7feb000, private=128) at ../sysdeps/unix/sysv/linux/x86/elision-unlock.c:29 29 ../sysdeps/unix/sysv/linux/x86/elision-unlock.c: No such file or directory. (gdb) bt #0 __lll_unlock_elision (lock=0x7ffff7feb000, private=128) at ../sysdeps/unix/sysv/linux/x86/elision-unlock.c:29 #1 0x00000000004482fa in fio_mutex_down_timeout (mutex=0x7ffff7feb000, msecs=10000) at mutex.c:141 #2 0x0000000000468dda in run_threads (sk_out=0x0) at backend.c:2183 #3 0x0000000000469487 in fio_backend (sk_out=0x0) at backend.c:2381 #4 0x0000000000486c42 in main (argc=2, argv=0x7fffffffdf18, envp=0x7fffffffdf30) at fio.c:63 -- Bruce