On 12-03-2015 PM 11:46, Amit Kapila wrote:
> [parallel_seqscan_v10.patch]
There may be a bug in TupleQueueFunnelNext().
1) I observed a hang with stack looking like:
#0 0x00000039696df098 in poll () from /lib64/libc.so.6
#1 0x00000000006f1c6a in WaitLatchOrSocket (latch=0x7f29dc3c73b4,
wakeEvents=1, sock=-1, timeout=0) at pg_latch.c:333
#2 0x00000000006f1aca in WaitLatch (latch=0x7f29dc3c73b4, wakeEvents=1,
timeout=0) at pg_latch.c:197
#3 0x000000000065088b in TupleQueueFunnelNext (funnel=0x17b4a20, nowait=0
'\000', done=0x17ad481 "") at tqueue.c:269
#4 0x0000000000636cab in funnel_getnext (funnelstate=0x17ad3d0) at
nodeFunnel.c:347
...
<snip>
2) In some cases, there can be a segmentation fault with stack looking like:
#0 0x000000396968990a in memcpy () from /lib64/libc.so.6
#1 0x00000000006507e7 in TupleQueueFunnelNext (funnel=0x263c800, nowait=0
'\000', done=0x2633461 "") at tqueue.c:233
#2 0x0000000000636cab in funnel_getnext (funnelstate=0x26333b0) at
nodeFunnel.c:347
#3 0x0000000000636901 in ExecFunnel (node=0x26333b0) at nodeFunnel.c:179
...
<snip>
I could get rid of (1) and (2) with the attached fix.