On Wed, Feb 5, 2014 at 7:21 AM, Andres Freund <and...@2ndquadrant.com> wrote: > All current x86 processors use 64. But even if it were bigger/smaller, > they will be either 32, or 128. Neither benefits from touching more > cachelines than necessary. E.g. in the 128 case, we could still touch > two with the current code.
That's true, but I believe that a hardware optimization called Adjacent Cache Line Prefetch is widely supported by recent microarchitectures, and is sometimes enabled by default. I'm not suggesting that that would necessarily radically alter the outcome, but it is a consideration. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers