More data.... On a dual xeon with HTT enabled:
I tried increasing the NUM_SPINS to 1000 and it works better. NUM_SPINLOCKS CS ID pgbench 100 250K 59% 230 TPS 1000 125K 55% 228 TPS This is certainly heading in the right direction ? Although it looks like it is highly dependent on the system you are running on. --dc-- On Wed, 2004-04-21 at 22:53, Josh Berkus wrote: > Tom, > > > As far as I can tell, this does reduce the rate of semop's > > significantly, but it does so by bringing the overall processing rate > > to a crawl :-(. I see 97% CPU idle time when using this patch. > > I believe what is happening is that the select() delay in s_lock.c is > > being hit frequently because the spin loop isn't allowed to run long > > enough to let the other processor get out of the spinlock. > > Also, I tested it on production data, and it reduces the CSes by about 40%. > An improvement, but not a magic bullet. -- Dave Cramer 519 939 0336 ICQ # 14675561 ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly