On Wed, Jan 28, 2015 at 10:35 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Andres Freund <and...@2ndquadrant.com> writes: >> On 2015-01-26 21:13:31 -0500, Robert Haas wrote: >>> So maybe we should also do something like what LWLocks do, and make a >>> union between the actual structure and an appropriate array of padding >>> bytes - say either 64 or 128 of them. > >> Hm. That's a bit bigger patch. I'm inclined to just let it slide for the >> moment. I still have plans to downsize some of sbufdesc's content (move >> the io lock out) and move the content lwlock inline. Then we're not >> going to have much choice but do this... > > Even if you didn't have plans like that, it would be entire folly to > imagine that buffer headers will be exactly 64 bytes without some forcing > function for that. Accordingly, I vote against applying any patch that > pretends to improve their alignment unless it also does something to > ensure that the size is a power of 2. Any notational changes that are > forced by that would be much better done in a patch that does only that > than in a patch that also makes functional changes to the header contents.
I entirely agree. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
