Re: Re: [COMMITTERS] pgsql: Allow Pin/UnpinBuffer to operate in a lockfree manner.

Andres Freund <andres(at)anarazel(dot)de> writes:
> The issue is likely that either Alexander or I somehow made
> MarkLocalBufferDirty() use pg_atomic_fetch_or_u32(), instead of the
> proper pg_atomic_read_u32()/pg_atomic_write_u32().

The stack trace I'm seeing is

#5 0x7279cc in elog_finish (elevel=6,
fmt=0x40057cf8 '\177' <repeats 200 times>...) at elog.c:1378
#6 0x5cecd8 in s_lock_stuck (p=0x402995b8, file=0x21bae0 "s_lock.c", line=92)
at s_lock.c:81
#7 0x5cedd4 in perform_spin_delay (status=0x7b03b8c8) at s_lock.c:130
#8 0x5ced40 in s_lock (lock=0x6, file=0x20 <Address 0x20 out of bounds>,
line=6) at s_lock.c:96
#9 0x53a4b0 in pg_atomic_compare_exchange_u32_impl (ptr=0x402995b8,
expected=0x5c, newval=58982400) at atomics.c:122
#10 0x5a280c in MarkLocalBufferDirty (buffer=6)
at ../../../../src/include/port/atomics/generic.h:224
#11 0x59bba0 in MarkBufferDirty (buffer=6) at bufmgr.c:1489
#12 0x2c9cd0 in heap_multi_insert (relation=0x401c41d0, tuples=0x40201888,
ntuples=561, cid=0, options=0, bistate=0x40153128) at heapam.c:2760

regards, tom lane