Robert, Tom,
On 2017-08-16 09:55:15 -0700, Andres Freund wrote: > > Not sure if this is your bug or if it's exposing a pre-existing > > deficiency in the atomics code, viz, failure to ensure that > > pg_atomic_uint64 is actually a 64-bit-aligned type. Andres? > I suspect it's the former. Suspect that the shared memory that holds > the "parallel desc" isn't properly aligned: Or, well, a mixture of both, because it seems like a deficiency in the shm_toc, code, rather than the atomics code. > Afaict shm_create/shm_toc_allocate don't actually guarantee that the end > of the toc's memory is suitably aligned. But I didn't yet have any > coffee, so ... Robert, I'm not quite sure what the intended behaviour of shm_toc is wrt alignment. I see that individual chunks are BUFFERALIGNed (both during estimation, and allocation). But I don't see how the size of the entire toc is aligned, which seems a requirement, given we allocate from the end. Seems like we'd just have to add alignment of the total size to shm_toc_estimate()? Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
