Maxime Henrion <[EMAIL PROTECTED]> writes: > Thanks for forwarding my mail, Kris! To Tom: if you can get my mails > to reach pgsql-hackers@ somehow that would be just great :-).
They'll get approved eventually, just like mine to the BSD lists will get approved eventually ;-) >> The only thing we could do to fix that from our end would be to use >> a smaller sema-set size on *BSD platforms. Is the overhead per sema set >> small enough to make this a sane thing to do? Will we be likely to >> run into system limits on the number of sets? > I'm not familiar enough with the PostgreSQL code to know what impact > such a change could have, but since the problem is clearly on our > side here, I would advise against doing changes in PostgreSQL that > are likely to complicate the code for little gain. We still didn't > even fully measure how much the useless wakups cost us since we're > running into other contention problems with my patch that removes > those. And, as you point out, there are complications ensuing with > respect to system limits (we already ask users to bump them when > they install PostgreSQL). OK, it was just an off-the-cuff idea. > I think the high number of setproctitle() calls are more problematic > to us at the moment, Kris can comment on that. As of PG 8.2 it is possible to turn those off. I don't think there's a lot of enthusiasm for turning them off by default ... at least not yet. But it might make sense to point out in the PG documentation that update_process_title is particularly costly on platforms X, Y, and Z. Do you know if this issue affects all the BSDen equally? regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate