------- Comment From [email protected] 2024-10-24 10:01 EDT------- (In reply to comment #14) > Vijay, Can you verify this bug ?
Hi, I ran pgbenach 5 times on Ubuntu 24.04 L2 Guest(kernel : 6.8.0-47-generic) with CEDE On and CEDE Off. I could see upto 50% degradation on L2-Guest CEDE ON vs L2-Guest CEDE OFF. CEDE On Results : PostgreSQL 17: pts/pgbench-1.15.0 [Scaling Factor: 100 - Clients: 50 - Mode: Read Only] Test 1 of 1 Estimated Trial Run Count: 5 Estimated Time To Completion: 13 Minutes [11:38 UTC] Started Run 1 @ 11:26:09 Started Run 2 @ 11:28:45 Started Run 3 @ 11:31:15 Started Run 4 @ 11:33:45 Started Run 5 @ 11:36:19 Scaling Factor: 100 - Clients: 50 - Mode: Read Only: 1188.782604 1240.626583 1295.409026 1284.232445 1194.451742 Average: 1241 TPS Deviation: 3.97% Samples: 5 Scaling Factor: 100 - Clients: 50 - Mode: Read Only - Average Latency: 6.73 6.448 6.176 6.229 6.698 Average: 6.456 ms Deviation: 3.98% Samples: 5 CEDE OFF Results : PostgreSQL 17: pts/pgbench-1.15.0 [Scaling Factor: 100 - Clients: 50 - Mode: Read Only] Test 1 of 1 Estimated Trial Run Count: 5 Estimated Time To Completion: 13 Minutes [12:07 UTC] Started Run 1 @ 11:55:05 Started Run 2 @ 11:57:38 Started Run 3 @ 12:00:14 Started Run 4 @ 12:02:45 Started Run 5 @ 12:05:15 Scaling Factor: 100 - Clients: 50 - Mode: Read Only: 2746.538132 2321.285623 2610.106716 2523.755346 2608.03977 Average: 2562 TPS Deviation: 6.11% Samples: 5 Scaling Factor: 100 - Clients: 50 - Mode: Read Only - Average Latency: 2.913 3.446 3.065 3.17 3.067 Average: 3.132 ms Deviation: 6.32% Samples: 5 ------- Comment From [email protected] 2024-10-24 10:02 EDT------- Config of KVM Host and L2-Guest: KVM Host Config : root@kvmfvt:~# cpupower idle-info CPUidle driver: pseries_idle CPUidle governor: menu analyzing CPU 1: Number of idle states: 2 Available idle states: snooze CEDE snooze: Flags/Description: snooze Latency: 0 Usage: 584282 Duration: 15772032 CEDE: Flags/Description: CEDE Latency: 12 Usage: 1693009 Duration: 569004764428 root@kvmfvt:~# numactl -H available: 1 nodes (1) node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 node 1 size: 49921 MB node 1 free: 859 MB node distances: node 1 1: 10 root@kvmfvt:~# cat /proc/cmdline BOOT_IMAGE=/boot/vmlinux-6.8.0-48-generic root=UUID=b25a666f-351f-4cb3-ae86-0c86f35ab749 ro crashkernel=2048M crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M root@kvmfvt:~# ################### L2-Guest CEDE ON Config : root@kvmfvt:~/phoronix-test-suite cat /etc/os-release PRETTY_NAME="Ubuntu 24.04.1 LTS" NAME="Ubuntu" VERSION_ID="24.04" VERSION="24.04.1 LTS (Noble Numbat)" VERSION_CODENAME=noble ID=ubuntu ID_LIKE=debian HOME_URL="https://www.ubuntu.com/"; SUPPORT_URL="https://help.ubuntu.com/"; BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"; PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"; UBUNTU_CODENAME=noble LOGO=ubuntu-logo root@kvmfvt:~/phoronix-test-suite cpupower idle-info CPUidle driver: pseries_idle CPUidle governor: menu analyzing CPU 4: Number of idle states: 2 Available idle states: snooze Shared Cede snooze: Flags/Description: snooze Latency: 0 Usage: 73705 Duration: 4272838 Shared Cede: Flags/Description: Shared Cede Latency: 10 Usage: 3667349 Duration: 570028915040 root@kvmfvt:~/phoronix-test-suite uname -a Linux kvmfvt 6.8.0-47-generic #47-Ubuntu SMP Fri Sep 27 21:38:55 UTC 2024 ppc64le ppc64le ppc64le GNU/Linux root@kvmfvt:~/phoronix-test-suite numactl -H available: 1 nodes (0) node 0 cpus: 0 1 2 3 4 5 6 7 node 0 size: 48342 MB node 0 free: 25566 MB node distances: node 0 0: 10 root@kvmfvt:~/phoronix-test-suite cat /proc/cmdline BOOT_IMAGE=/vmlinux-6.8.0-47-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro crashkernel=2048M crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M L2-Guest CEDE OFF Config : root@kvmfvt:~/phoronix-test-suite cpupower idle-info CPUidle driver: pseries_idle CPUidle governor: menu analyzing CPU 4: Number of idle states: 2 Available idle states: snooze Shared Cede snooze: Flags/Description: snooze Latency: 0 Usage: 641899 Duration: 61252357 Shared Cede (DISABLED) : Flags/Description: Shared Cede Latency: 10 Usage: 3667645 Duration: 570100106856 root@kvmfvt:~/phoronix-test-suite cat /proc/cmdline BOOT_IMAGE=/vmlinux-6.8.0-47-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro crashkernel=2048M crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M root@kvmfvt:~/phoronix-test-suite numactl -H available: 1 nodes (0) node 0 cpus: 0 1 2 3 4 5 6 7 node 0 size: 48342 MB node 0 free: 25565 MB node distances: node 0 0: 10 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2070253 Title: KVM on PowerVM: L2 Guest-Aggressively entering CEDE results in low performance. Possible tuning opportunity. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/2070253/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
