Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Tom Lane wrote:
>> Well, strictly speaking, there were no uses of pg_read_barrier until 9.4.
>> However, pg_write_barrier (which used "wmb") was in use since 9.2; so
>> unless you're claiming your assembler knows wmb but not rmb, the code's
>> failed to compile for Alpha since 9.2.
> Actually according to this
> http://www.cs.cmu.edu/afs/cs.cmu.edu/academic/class/15213-f98/doc/alpha-asm.pdf
> there is a wmb instruction but there is no rmb.
Oh really? If rmb were a figment of someone's imagination, it would
explain the build failure (although not why nobody's reported it till
now).
It'd be easy enough to s/rmb/mb/ in 9.4 ... but not sure it's worth
the trouble, since we're desupporting Alpha as of 9.5 anyway. If the
effective desupport date is 9.4 instead, how much difference does that
make?
regards, tom lane