On Wed, Jul 20, 2011 at 09:46:33PM -0400, Robert Haas wrote: > Profiling this combination of patches reveals that there is still some > pretty ugly spinlock contention on sinval's msgNumLock. And it occurs > to me that on x86, we really don't need this lock ... or > SInvalReadLock ... or a per-backend mutex. The whole of > SIGetDataEntries() can pretty easily be made lock-free. The only real > changes that seem to be are needed are (1) to use a 64-bit counter, so > you never need to decrement
On second thought, won't this be inadequate on 32-bit systems, where updating the 64-bit counter produces two stores? You must avoid reading it between those stores. -- Noah Misch http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
