>> With help from IBM Japan Ltd. we did some tests on a larger IBM >> machine than Tom Lane has used for his >> test(http://archives.postgresql.org/message-id/8292.1314641...@sss.pgh.pa.us). >> In his case it was IBM 8406-71Y, which has 8 physical cores and >> 4SMT(32 threadings). Ours is IBM Power 750 Express, which has 32 >> physical cores and 4SMT(128 threadings), 256GB RAM. >> >> The test method was same as the one in the article above. The >> differences are OS(RHEL 6.1), gcc version (4.4.5) and shared buffer >> size(8GB). >> >> We tested 3 methods to enhance spin lock contention: >> >> 1) Add "hint" parameter to lwarx op which is usable POWER6 or later >> architecure. >> >> 2) Add non-locked test in TAS() >> >> 3) #1 + #2 >> >> We saw small performance enhancement with #1, larger one with #2 and >> even better with #1+#2. > > Hmm, so you added the non-locked test in TAS()? Did you try adding it > just to TAS_SPIN()? On Itanium, I found that it was slightly better > to do it only in TAS_SPIN() - i.e. in the contended case.
The actual test was performed by one of our engineers in my company (Toshihiro Kitagawa). I think the answer to your question is yes, but let me talk to him to make it sure. -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers