Comment # 7 on bug 949906 from Vitaliy Margolen

That was with debug information. But here it is again. Started with
LD_PRELOAD=/lib64/noelision/libpthread.so.0 /usr/sbin/glusterfs <long list of
arguments>


[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `/usr/sbin/glusterfs -s localhost --volfile-id
rebalance/gv1 --xlator-option *dh'.
Program terminated with signal SIGILL, Illegal instruction.
#0  0x00007fdf8793b0ab in _xbegin () at
../nptl/sysdeps/unix/sysv/linux/x86/hle.h:53
53      ../nptl/sysdeps/unix/sysv/linux/x86/hle.h: No such file or directory.
Missing separate debuginfos, use: zypper install
glusterfs-debuginfo-3.7.9-100.1.x86_64
(gdb) bt
#0  0x00007fdf8793b0ab in _xbegin () at
../nptl/sysdeps/unix/sysv/linux/x86/hle.h:53
#1  __lll_lock_elision (futex=0x7fdedeffd700, adapt_count=0x7fdedeffd716,
private=0) at ../nptl/sysdeps/unix/sysv/linux/x86/elision-lock.c:56
#2  0x00007fdf876a4fc9 in inode_ref () from /usr/lib64/libglusterfs.so.0
#3  0x00007fdf87682afa in loc_copy () from /usr/lib64/libglusterfs.so.0
#4  0x00007fdf81ac629b in dht_local_init () from
/usr/lib64/glusterfs/3.7.9/xlator/cluster/distribute.so
#5  0x00007fdf81af9401 in dht_lookup () from
/usr/lib64/glusterfs/3.7.9/xlator/cluster/distribute.so
#6  0x00007fdf876c91c2 in syncop_lookup () from /usr/lib64/libglusterfs.so.0
#7  0x00007fdf81acdf0a in gf_defrag_fix_layout () from
/usr/lib64/glusterfs/3.7.9/xlator/cluster/distribute.so
#8  0x00007fdf81acf2d6 in gf_defrag_start_crawl () from
/usr/lib64/glusterfs/3.7.9/xlator/cluster/distribute.so
#9  0x00007fdf876c5a32 in synctask_wrap () from /usr/lib64/libglusterfs.so.0
#10 0x00007fdf86cc0f20 in ?? () from /lib64/libc.so.6
#11 0x0000000000000000 in ?? ()
(gdb) disassemble 
Dump of assembler code for function __lll_lock_elision:
   0x00007fdf8793b060 <+0>:     movzwl (%rsi),%eax
   0x00007fdf8793b063 <+3>:     mov    %rdi,%r8
   0x00007fdf8793b066 <+6>:     test   %ax,%ax
   0x00007fdf8793b069 <+9>:     jle    0x7fdf8793b088 <__lll_lock_elision+40>
   0x00007fdf8793b06b <+11>:    sub    $0x1,%eax
   0x00007fdf8793b06e <+14>:    mov    %ax,(%rsi)
   0x00007fdf8793b071 <+17>:    mov    $0x1,%edi
   0x00007fdf8793b076 <+22>:    xor    %eax,%eax
   0x00007fdf8793b078 <+24>:    mov    %edx,%esi
   0x00007fdf8793b07a <+26>:    lock cmpxchg %edi,(%r8)
   0x00007fdf8793b07f <+31>:    jne    0x7fdf8793b0fb <_L_lock_49>
   0x00007fdf8793b081 <+33>:    xor    %eax,%eax
   0x00007fdf8793b083 <+35>:    retq   
   0x00007fdf8793b084 <+36>:    nopl   0x0(%rax)
   0x00007fdf8793b088 <+40>:    mov    0x20722a(%rip),%ecx        #
0x7fdf87b422b8 <__elision_aconf+8>
   0x00007fdf8793b08e <+46>:    mov    $0xffffffff,%edi
   0x00007fdf8793b093 <+51>:    test   %ecx,%ecx
   0x00007fdf8793b095 <+53>:    jg     0x7fdf8793b0a9 <__lll_lock_elision+73>
   0x00007fdf8793b097 <+55>:    jmp    0x7fdf8793b071 <__lll_lock_elision+17>
   0x00007fdf8793b099 <+57>:    nopl   0x0(%rax)
   0x00007fdf8793b0a0 <+64>:    test   $0x2,%al
   0x00007fdf8793b0a2 <+66>:    je     0x7fdf8793b0c8 <__lll_lock_elision+104>
   0x00007fdf8793b0a4 <+68>:    sub    $0x1,%ecx
   0x00007fdf8793b0a7 <+71>:    je     0x7fdf8793b071 <__lll_lock_elision+17>
   0x00007fdf8793b0a9 <+73>:    mov    %edi,%eax
=> 0x00007fdf8793b0ab <+75>:    xbeginq 0x7fdf8793b0b1 <__lll_lock_elision+81>
   0x00007fdf8793b0b1 <+81>:    cmp    $0xffffffff,%eax
   0x00007fdf8793b0b4 <+84>:    jne    0x7fdf8793b0a0 <__lll_lock_elision+64>
   0x00007fdf8793b0b6 <+86>:    mov    (%r8),%eax
   0x00007fdf8793b0b9 <+89>:    test   %eax,%eax
   0x00007fdf8793b0bb <+91>:    je     0x7fdf8793b081 <__lll_lock_elision+33>
   0x00007fdf8793b0bd <+93>:    xabort $0xff
   0x00007fdf8793b0c0 <+96>:    jmp    0x7fdf8793b0a4 <__lll_lock_elision+68>
   0x00007fdf8793b0c2 <+98>:    nopw   0x0(%rax,%rax,1)
   0x00007fdf8793b0c8 <+104>:   test   $0x1,%al
   0x00007fdf8793b0ca <+106>:   je     0x7fdf8793b0d6 <__lll_lock_elision+118>
   0x00007fdf8793b0cc <+108>:   shr    $0x18,%eax
   0x00007fdf8793b0cf <+111>:   cmp    $0xff,%eax
   0x00007fdf8793b0d4 <+116>:   je     0x7fdf8793b0e5 <__lll_lock_elision+133>
   0x00007fdf8793b0d6 <+118>:   movswl (%rsi),%ecx
   0x00007fdf8793b0d9 <+121>:   mov    0x2071d5(%rip),%eax        #
0x7fdf87b422b4 <__elision_aconf+4>
   0x00007fdf8793b0df <+127>:   cmp    %eax,%ecx
   0x00007fdf8793b0e1 <+129>:   jne    0x7fdf8793b06e <__lll_lock_elision+14>
   0x00007fdf8793b0e3 <+131>:   jmp    0x7fdf8793b071 <__lll_lock_elision+17>
   0x00007fdf8793b0e5 <+133>:   movswl (%rsi),%ecx
   0x00007fdf8793b0e8 <+136>:   mov    0x2071c2(%rip),%eax        #
0x7fdf87b422b0 <__elision_aconf>
   0x00007fdf8793b0ee <+142>:   cmp    %eax,%ecx
   0x00007fdf8793b0f0 <+144>:   jne    0x7fdf8793b06e <__lll_lock_elision+14>
   0x00007fdf8793b0f6 <+150>:   jmpq   0x7fdf8793b071 <__lll_lock_elision+17>
End of assembler dump.