Hi! On Fri, Oct 30, 2015 at 5:12 PM, Andres Freund <and...@anarazel.de> wrote:
> On 2015-10-30 16:28:22 +0300, Alexander Korotkov wrote: > > pinunpin-cas-original-fix.patch is just original patch by Andres Freund > > with fixed bug which causes hang. > > Performance comparison on 72-cores Intel server in attached. On this > > machine we see no regression in version of patch in previous letter. > > So pinunpin-cas-original-fix is my version with a bug fixed, and > pinunpin-cas is what exactly? Your earlier version with the xadd + > cmpxchg? > pinunpin-cas is still just cmpxchg with no xadd. It contain just minor changes: Refactored version of atomic state patch is attached. The changes are > following: > 1) Macros are used for access refcount and usagecount. > 2) likely/unlikely were removed. I think introducing of likely/unlikely > should be a separate patch since it touches portability. Also, I didn't see > any performance effect of this. > 3) LockBufHdr returns the state after taking lock. Without using atomic > increments it still can save some loops on skip atomic value reading. I compare them just to show there is no regression because of these changes. > The results look pretty good. Could you give a few more details about > the hardware and workload (i.e. cpu model number + scale)? > It is 4 socket Intel(R) Xeon(R) CPU E7-8890 v3 @ 2.50GHz, 2 Tb of memory, all data in shared_buffers, 1000 scale factor, -M prepared, pgbench runs on the same maching through unix socket. > So the plan would be to finish cleaning this up into a committable > shape? > Yes. ------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
