On Sat, 2009-01-10 at 19:16 +0900, Fujii Masao wrote: > On Thu, Dec 18, 2008 at 9:55 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > >> 4. sleeping > >> http://archives.postgresql.org/pgsql-hackers/2008-12/msg00438.php > >> > >> I'm looking for the better idea. How should we resolve that problem? > >> Only reduce the timeout of pq_wait to 100ms? Get rid of > >> SA_RESTART only during pq_wait as follows? > >> > >> remove SA_RESTART > >> pq_wait() > >> add SA_RESTART > > > > Not sure, will consider. Ask others as well. > > I've not got an idea yet. Now (v5), I only reduce the timeout of > pq_wait to 100ms. Is this sufficient? Do you have any good idea?
To be honest I didn't follow that part of the discussion. My preferred approach, mentioned earlier in the summer, was to use a mechanism very similar to LWlocks. A proc queue with semaphores. Minimum delay, no need for signals. The process doing the wakeup can walk up the queue until it finds somebody whose wait-for-LSN is higher than has just been sent/written. Doing it this way also gives us group commit when synch rep is not enabled. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
