Comment 1 for bug 140834

A simple invocation of python shows them apparently being hit at startup and on imports:

mbp@hope% strace -e trace=futex python -c import\ pdb -c import\ pdb
futex(0x816a048, FUTEX_WAKE, 1) = 0
futex(0x816a048, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x818bd00, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0xb7e98a6c, FUTEX_WAKE, 2147483647) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0xb7ec9070, FUTEX_WAKE, 2147483647) = 0
futex(0x8171df8, FUTEX_WAKE, 1) = 0
futex(0x818bd00, FUTEX_WAKE, 1) = 0
futex(0x816a048, FUTEX_WAKE, 1) = 0
futex(0x816a048, FUTEX_WAKE, 1) = 0
futex(0x816a048, FUTEX_WAKE, 1) = 0

mbp@hope% strace -e trace=futex python
futex(0x816a038, FUTEX_WAKE, 1) = 0
futex(0x816a038, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x818bcf0, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0xb7f76a6c, FUTEX_WAKE, 2147483647) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
Python 2.5.1 (r251:54863, Sep 11 2007, 23:45:37)
[GCC 4.1.3 20070831 (prerelease) (Ubuntu 4.1.2-16ubuntu1)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
futex(0x8171de8, FUTEX_WAKE, 1) = 0
futex(0xb7fa7070, FUTEX_WAKE, 2147483647) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
>>> import pdb
futex(0x81cbb98, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
>>> import pdb
futex(0x81cbb98, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
>>> import pdb
futex(0x81cbb98, FUTEX_WAKE, 1) = 0
futex(0x8171de8, FUTEX_WAKE, 1) = 0
>>> futex(0x81cbb98, FUTEX_WAKE, 1) = 0

futex(0x818bcf0, FUTEX_WAKE, 1) = 0
futex(0x816a038, FUTEX_WAKE, 1) = 0
futex(0x816a038, FUTEX_WAKE, 1) = 0
futex(0x816a038, FUTEX_WAKE, 1) = 0
Process 7104 detached

note that in the second case we can't be 100% sure this is due to the import rather than some consequence of the interactive session.