Comment # 6 on bug 917810 from Leonardo Chiquitto

When I run the code from comment #4 on my machine (glibc-2.20-2.2.x86_64),
after pthread_mutex_lock():

> (gdb) p/x mutex
> $2 = {__data = {__lock = 0x1, __count = 0x0, __owner = 0xedf, __nusers = 0x1, __kind = 0x0, __spins = 0x0, 
>     __elision = 0x0, __list = {__prev = 0x0, __next = 0x0}}, __size = {0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xdf, 
>     0xe, 0x0, 0x0, 0x1, 0x0 <repeats 27 times>}, __align = 0x1}

The same on Dirk's machine (glibc-2.19-19.1.x86_64):

> (gdb) p/x mutex
> $1 = {__data = {__lock = 0x1, __count = 0x0, __owner = 0x0, __nusers = 0x0, __kind = 0x100, __spins = 0x0,
>      __elision = 0x3, __list = {__prev = 0x0, __next = 0x0}}, __size = {0x1, 0x0 <repeats 16 times>, 0x1, 0x0, 0x0,
>      0x0, 0x0, 0x3, 0x0 <repeats 17 times>}, __align = 0x1}

How do I tell glibc to use lock elision? Dirk, perhaps you still have those
workarounds to run Groupwise and they're getting on the way?