Hi,
From time to time, I see check-all hang during running of lit tests.
The hang always happens at the > 90% completion stage and I'm pretty
sure all tests have been run and check-all is just waiting for
lit/python to exit. I see a single python processing running, taking
very little CPU time. An strace of that process shows this:
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 32168}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 1000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 2000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 4000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 8000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 16000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 32000}) = 0 (Timeout)
futex(0x3bcc8c0, FUTEX_WAKE_PRIVATE, 1) = 1
futex(0x3bcc8c0, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 0, NULL, ffffffff) = 0
futex(0x3bcc8c0, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 0, NULL, ffffffff) = -1 EAGAIN (Resourc
e temporarily unavailable)
futex(0x3bcc8c0, FUTEX_WAKE_PRIVATE, 1) = 1
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
futex(0x3bcc8c0, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 0, NULL, ffffffff) = -1 EAGAIN (Resourc
e temporarily unavailable)
futex(0x3bcc8c0, FUTEX_WAKE_PRIVATE, 1) = 1
futex(0x3bcc8c0, FUTEX_WAKE_PRIVATE, 1) = 1
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
select(0, NULL, NULL, NULL, {0, 50000}) = 0 (Timeout)
It appears that python is waiting for some I/O or something which never
appears.
Has anyone else seen this before? Any ideas of what is going on or how
to fix it?
-David
:parser<llvm::ScheduleDAGInstrs *(*)(llvm::MachineSchedContext *)>::addLiteralOption(llvm::StringRef, const DT &, llvm::StringRef) [DataType = llvm::ScheduleDAGInstrs *(*)(llvm::MachineSchedContext *), DT = llvm::ScheduleDAGInstrs *(*)(llvm::MachineSchedContext *)]: Assertion `findOption(Name) == Values.size() && "Option already exists!"' failed.