On Tue, Jan 5, 2016 at 04:31:15PM +0100, Andres Freund wrote: > On 2016-01-05 10:28:25 -0500, Bruce Momjian wrote: > > On Sun, Dec 13, 2015 at 12:35:34PM +0100, Andres Freund wrote: > > > > > One thing to call out is that an "oversized" s_lock can now make > > > > > BufferDesc exceed 64 bytes, right now that's just the case when it's > > > > > larger than 4 bytes. I'm not sure if that's cause for real concern, > > > > > given that it's not very concurrent or ancient platforms where that's > > > > > the case. > > > > > http://archives.postgresql.org/message-id/20150915020625.GI9666%40alap3.anarazel.de > > > > > would alleviate that concern again, as it collapses flags, > > > > > usage_count, > > > > > buf_hdr_lock and refcount into one 32 bit int... > > > > > > > > I don't think that would be worth worrying about even if we didn't > > > > have a plan in mind that would make it go away again, and even less so > > > > given that we do have such a plan. > > > > > > Ok cool. I'm not particularly concerned either, just didn't want to slip > > > that in without having it called out. > > > > Uh, didn't you and I work in 9.5 to make sure the BufferDesc was 64-byte > > aligned to avoid double-CPU cache invalidation that was causing > > performance problems on a server you were testing? > > Yes? But it's ok sizewise on the common platforms?
What is the uncommon part? I guess I missed that. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Roman grave inscription + -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers