On 4/18/10, Simon Riggs <si...@2ndquadrant.com> wrote: > On Sat, 2010-04-17 at 16:48 -0400, Tom Lane wrote: > > There are some places where we suppose that a *single* write into shared > > memory can safely be done without a lock, if we're not too concerned > > about how soon other transactions will see the effects. But what you > > are proposing here requires more than one related write. > > > > I've been burnt by this myself: > > http://archives.postgresql.org/pgsql-committers/2008-06/msg00228.php > > > W O W - thank you for sharing. > > What I'm not clear on is why you've used a spinlock everywhere when only > weak-memory thang CPUs are a problem. Why not have a weak-memory-protect > macro that does does nada when the hardware already protects us? (i.e. a > spinlock only for the hardware that needs it).
Um, you have been burned by exactly this on x86 also: http://archives.postgresql.org/pgsql-hackers/2009-03/msg01265.php -- marko -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
