http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52526
Bug #: 52526
Summary: libitm: stuck in futex_wait
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libitm
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: patrick.marl...@gmail.com
CC: torv...@gcc.gnu.org
Host: x86_64-unknown-linux-gnu
Target: x86_64-unknown-linux-gnu
libitm (default configuration/4.8.0 20120307) is stuck in futex_wait with STAMP
kmeans with low contention and 8 threads.
(gdb) info threads
Id Target Id Frame
8 Thread 0x7ffff322b700 (LWP 24011) "kmeans" 0x0000003ecb40c14c in
pthread_barrier_wait () from /lib64/libpthread.so.0
7 Thread 0x7ffff3a2c700 (LWP 24010) "kmeans" 0x0000003ecb40c14c in
pthread_barrier_wait () from /lib64/libpthread.so.0
6 Thread 0x7ffff422d700 (LWP 24009) "kmeans" 0x0000003ecb40c14c in
pthread_barrier_wait () from /lib64/libpthread.so.0
5 Thread 0x7ffff4a2e700 (LWP 24008) "kmeans" 0x0000003ecb40c14c in
pthread_barrier_wait () from /lib64/libpthread.so.0
* 4 Thread 0x7ffff522f700 (LWP 24007) "kmeans" GTM::futex_wait
(addr=0x7ffff7fdfbb8, val=1)
at ../../../gcc-trunk/libitm/config/linux/futex.cc:49
3 Thread 0x7ffff5a30700 (LWP 24006) "kmeans" 0x0000003ecb40c14c in
pthread_barrier_wait () from /lib64/libpthread.so.0
2 Thread 0x7ffff6231700 (LWP 24005) "kmeans" 0x0000003ecb40c14c in
pthread_barrier_wait () from /lib64/libpthread.so.0
1 Thread 0x7ffff73aa720 (LWP 24002) "kmeans" 0x0000003ecb40c14c in
pthread_barrier_wait () from /lib64/libpthread.so.0
(gdb) thread 5
[Switching to thread 5 (Thread 0x7ffff4a2e700 (LWP 24008))]
#0 0x0000003ecb40c14c in pthread_barrier_wait () from /lib64/libpthread.so.0
(gdb) bt
#0 0x0000003ecb40c14c in pthread_barrier_wait () from /lib64/libpthread.so.0
#1 0x0000000000403099 in threadWait ()
#2 0x0000003ecb407b41 in start_thread () from /lib64/libpthread.so.0
#3 0x0000003eca8df49d in clone () from /lib64/libc.so.6
(gdb) thread 4
[Switching to thread 4 (Thread 0x7ffff522f700 (LWP 24007))]
#0 GTM::futex_wait (addr=0x7ffff7fdfbb8, val=1) at
../../../gcc-trunk/libitm/config/linux/futex.cc:49
49 if (__builtin_expect (res == -ENOSYS, 0))
(gdb) bt
#0 GTM::futex_wait (addr=0x7ffff7fdfbb8, val=1) at
../../../gcc-trunk/libitm/config/linux/futex.cc:49
#1 0x00007ffff75cd1a4 in GTM::gtm_rwlock::read_lock (this=0x7ffff7fdfbb0,
tx=0x7fffd40008c0)
at ../../../gcc-trunk/libitm/config/linux/rwlock.cc:76
#2 0x00007ffff75ccbfa in GTM::gtm_thread::decide_begin_dispatch
(this=0x7fffd40008c0, prop=<optimized out>)
at ../../../gcc-trunk/libitm/retry.cc:182
#3 0x00007ffff75cc16b in GTM_begin_transaction (prop=41, jb=0x7ffff522edb0) at
../../../gcc-trunk/libitm/beginend.cc:235
#4 0x00007ffff75cd853 in _ITM_beginTransaction () at
../../../gcc-trunk/libitm/config/x86/sjlj.S:74
#5 0x00000000004021ab in work ()
#6 0x000000000040308d in threadWait ()
#7 0x0000003ecb407b41 in start_thread () from /lib64/libpthread.so.0
#8 0x0000003eca8df49d in clone () from /lib64/libc.so.6
