On Sun, 2010-04-18 at 13:16 -0700, David Fetter wrote: > On Sun, Apr 18, 2010 at 12:01:05PM +0100, Simon Riggs wrote: > > On Sun, 2010-04-18 at 08:24 +0100, Simon Riggs wrote: > > > On Sat, 2010-04-17 at 18:52 -0400, Tom Lane wrote: > > > > Simon Riggs <si...@2ndquadrant.com> writes: > > > > > 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). > > > > > > > > Well, we could certainly consider that, if we had enough places > > > > where there was a demonstrable benefit from it. I couldn't > > > > measure any real slowdown from adding a spinlock in that sinval > > > > code, so I didn't propose doing so at the time --- and I'm > > > > pretty dubious that this code is sufficiently > > > > performance-critical to justify the work, either. > > > > > > OK, I'll put a spinlock around access to the head of the array. > > > > v2 patch attached > > If you've committed this, or any other patch you've sent here, > *please* mention so on the same thread.
I haven't yet. I've written two patches - this is a major module rewrite and is still under discussion. The other patch has nothing to do with this (though I did accidentally include a couple of changes from this patch and immediately revoked them). I will wait awhile to see if anybody has some independent test results. -- Simon Riggs www.2ndQuadrant.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
