Finally managed to do some testing with AMD EPYC 7401P on CentOS 7.4 with both default 3.10 Linux Kernel and 4.15 Linux Kernel. But I ran into some cpu soft lockups during UnixBench test and was wondering if anyone else have run into these before Benchmarks - Packet.net bare metal cloud provider review & benchmarks ?
seems raising the kernel.watchdog_thresh value from 10 seconds to 20 seconds fixed it though. But haven't seem anyone mention this yet and whether it's unique to AMD EPYC + CentOS combo on ELrepo mainline 4.15 kernels ?
Also seems there were definite performance improvements switching from CentOS 7.4 3.10 Kernels to 4.15 mainline Kernels i.e. building binutils 2.30 + GCC 8.0.1 profile guided optimization based RPMs for CentOS 7 were ~38% faster on newer Kernel
Code:
uname -r
4.15.5-1.el7.elrepo.x86_64
Code:
48 x Dhrystone 2 using register variables 1 2 3 4 5 6 7 8 9 10
48 x Double-Precision Whetstone 1 2 3 4 5 6 7 8 9 10
48 x System Call Overhead 1 2 3 4 5 6 7 8 9 10
48 x Pipe Throughput 1 2 3 4 5 6 7 8 9 10
48 x Pipe-based Context Switching 1 2 3 4 5
Message from syslogd@epyc at Feb 26 12:39:47 ...
kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [sshd:72234]
Message from syslogd@epyc at Feb 26 12:39:51 ...
kernel:watchdog: BUG: soft lockup - CPU#21 stuck for 22s! [context1:72109]
Message from syslogd@epyc at Feb 26 12:40:03 ...
kernel:watchdog: BUG: soft lockup - CPU#8 stuck for 22s! [kworker/8:0:4089]
Message from syslogd@epyc at Feb 26 12:40:15 ...
kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [sshd:72234]
Message from syslogd@epyc at Feb 26 12:40:19 ...
kernel:watchdog: BUG: soft lockup - CPU#21 stuck for 22s! [context1:72109]
Message from syslogd@epyc at Feb 26 12:40:31 ...
kernel:watchdog: BUG: soft lockup - CPU#8 stuck for 22s! [kworker/8:0:4089]
Also seems there were definite performance improvements switching from CentOS 7.4 3.10 Kernels to 4.15 mainline Kernels i.e. building binutils 2.30 + GCC 8.0.1 profile guided optimization based RPMs for CentOS 7 were ~38% faster on newer Kernel