On 2014-10-30 10:23:56 +0530, Amit Kapila wrote: > I have a feeling that this might also have some regression at higher > loads (like scale_factor = 5000, shared_buffers = 8GB, > client_count = 128, 256) for the similar reasons as bgreclaimer patch, > means although both reduces contention around spin lock, however > it moves contention somewhere else. I have yet to take data before > concluding anything (I am just waiting for your other patch (wait free > LW_SHARED) to be committed).
I have a hard time to see how this could be. In the uncontended case the number of cachelines touched and the number of atomic operations is exactly the same. In the contended case the new implementation does far fewer atomic ops - and doesn't do spinning. What's your theory? Greetings, Andres Freund -- Andres Freund 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
