From ea190fa699ec770c1c56467ebe3c62265afad53b Mon Sep 17 00:00:00 2001 From: Jiebin Sun Date: Fri, 13 Sep 2024 01:48:34 +0800 Subject: [PATCH] Increase the threshold of smt/none_smt to improve the performance Current threshold of smt/none_smt is 32. I have tuned the performance with Clickbench on 80x2 vCPUs system. If the total vCPUs is larger than 80, the performance would be better without smt. Signed-off-by: Jiebin Sun --- src/Common/getNumberOfPhysicalCPUCores.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/Common/getNumberOfPhysicalCPUCores.cpp b/src/Common/getNumberOfPhysicalCPUCores.cpp index 34a1add2f0e..9dd14584168 100644 --- a/src/Common/getNumberOfPhysicalCPUCores.cpp +++ b/src/Common/getNumberOfPhysicalCPUCores.cpp @@ -176,7 +176,7 @@ unsigned getNumberOfPhysicalCPUCoresImpl() /// /// On really big machines, SMT is detrimental to performance (+ ~5% overhead in ClickBench). On such machines, we limit ourself to the physical cores. /// Few cores indicate it is a small machine, runs in a VM or is a limited cloud instance --> it is reasonable to use all the cores. - if (cores >= 32) + if (cores >= 64) cores = physical_concurrency(); #endif