Greg Stark <gsstark@mit.edu> writes:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
>> We'd have to make sure zero is never the *correct* value of the offset,
>> but that just means wasting one word, which seems no problem.
> In theory it's possible for only half the word to be written or even to have
> outright garbage show up. In practice I think there are no actual
> architectures where this can really happen though.
Not an issue, because we have a lock around the read or write of the
slru buffer page. The problem is that there's no lock continuously held
through the creation of a multixact entry, and we don't really wish to
add one ...
regards, tom lane