Hello again, when the iozone writes slow. This is how slabtop looks like: 62476752 62476728 0% 0.10K 1601968 39 6407872K buffer_head 1000678 999168 0% 0.56K 142954 7 571816K radix_tree_node 132184 125911 0% 0.03K 1066 124 4264K kmalloc-32 118496 118224 0% 0.12K 3703 32 14812K kmalloc-node 73206 56467 0% 0.19K 3486 21 13944K dentry 34816 33247 0% 0.12K 1024 34 4096K kernfs_node_cache 34496 29031 0% 0.06K 539 64 2156K kmalloc-64 23283 22707 0% 1.05K 7761 3 31044K ext4_inode_cache 16940 16052 0% 0.57K 2420 7 9680K inode_cache 14464 4124 0% 0.06K 226 64 904K anon_vma_chain 11900 11841 0% 0.14K 425 28 1700K ext4_groupinfo_4k 11312 9861 0% 0.50K 1414 8 5656K kmalloc-512 10692 10066 0% 0.04K 108 99 432K ext4_extent_status 10688 4238 0% 0.25K 668 16 2672K kmalloc-256 8120 2420 0% 0.07K 145 56 580K anon_vma 8040 4563 0% 0.20K 402 20 1608K vm_area_struct 7488 3845 0% 0.12K 234 32 936K kmalloc-96 7456 7061 0% 1.00K 1864 4 7456K kmalloc-1024 7234 7227 0% 4.00K 7234 1 28936K kmalloc-4096 and this is /proc/$PID/stack of iozone eating CPU but not writing data. [<ffffffffba78151b>] find_get_entry+0x1b/0x100 [<ffffffffba781de0>] pagecache_get_page+0x30/0x2a0 [<ffffffffc06ec12b>] ext4_da_get_block_prep+0x27b/0x440 [ext4] [<ffffffffba840d8b>] __find_get_block_slow+0x3b/0x150 [<ffffffffba840ebd>] unmap_underlying_metadata+0x1d/0x70 [<ffffffffc06ec960>] ext4_block_write_begin+0x2e0/0x520 [ext4] [<ffffffffc06ebeb0>] ext4_inode_attach_jinode.part.72+0xa0/0xa0 [ext4] [<ffffffffc041f9f9>] jbd2__journal_start+0xd9/0x1e0 [jbd2] [<ffffffffba80511a>] __check_object_size+0xfa/0x1d8 [<ffffffffba946b85>] iov_iter_copy_from_user_atomic+0xa5/0x330 [<ffffffffba780dcb>] generic_perform_write+0xfb/0x1d0 [<ffffffffba7831ca>] __generic_file_write_iter+0x16a/0x1b0 [<ffffffffc06e7220>] ext4_file_write_iter+0x90/0x370 [ext4] [<ffffffffc06e7190>] ext4_dax_fault+0x140/0x140 [ext4] [<ffffffffba6aef01>] update_curr+0xe1/0x160 [<ffffffffba808890>] new_sync_write+0xe0/0x130 [<ffffffffba809010>] vfs_write+0xb0/0x190 [<ffffffffba80a452>] SyS_write+0x52/0xc0 [<ffffffffba603b7d>] do_syscall_64+0x8d/0xf0 [<ffffffffbac15c4e>] entry_SYSCALL_64_after_swapgs+0x58/0xc6 [<ffffffffffffffff>] 0xffffffffffffffff On Fri, Sep 14, 2018 at 03:36:59PM +0200, Lukas Hejtmanek wrote: > Hello, > > ok, I found that cpu pinning was wrong, so I corrected it to be 1:1. The issue > with iozone remains the same. > > The spec is running, however, it runs slower than 1-NUMA case. > > The corrected XML looks like follows: > <cpu mode='host-passthrough'><topology sockets='8' cores='4' threads='1'/><numa><cell cpus='0-3' memory='62000000' /><cell cpus='4-7' memory='62000000' /><cell cpus='8-11' memory='62000000' /><cell cpus='12-15' memory='62000000' /><cell cpus='16-19' memory='62000000' /><cell cpus='20-23' memory='62000000' /><cell cpus='24-27' memory='62000000' /><cell cpus='28-31' memory='62000000' /></numa></cpu> > <cputune><vcpupin vcpu='0' cpuset='0' /><vcpupin vcpu='1' cpuset='1' /><vcpupin vcpu='2' cpuset='2' /><vcpupin vcpu='3' cpuset='3' /><vcpupin vcpu='4' cpuset='4' /><vcpupin vcpu='5' cpuset='5' /><vcpupin vcpu='6' cpuset='6' /><vcpupin vcpu='7' cpuset='7' /><vcpupin vcpu='8' cpuset='8' /><vcpupin vcpu='9' cpuset='9' /><vcpupin vcpu='10' cpuset='10' /><vcpupin vcpu='11' cpuset='11' /><vcpupin vcpu='12' cpuset='12' /><vcpupin vcpu='13' cpuset='13' /><vcpupin vcpu='14' cpuset='14' /><vcpupin vcpu='15' cpuset='15' /><vcpupin vcpu='16' cpuset='16' /><vcpupin vcpu='17' cpuset='17' /><vcpupin vcpu='18' cpuset='18' /><vcpupin vcpu='19' cpuset='19' /><vcpupin vcpu='20' cpuset='20' /><vcpupin vcpu='21' cpuset='21' /><vcpupin vcpu='22' cpuset='22' /><vcpupin vcpu='23' cpuset='23' /><vcpupin vcpu='24' cpuset='24' /><vcpupin vcpu='25' cpuset='25' /><vcpupin vcpu='26' cpuset='26' /><vcpupin vcpu='27' cpuset='27' /><vcpupin vcpu='28' cpuset='28' /><vcpupin vcpu='29' cpuset='29' /><vcpupin vcpu='30' cpuset='30' /><vcpupin vcpu='31' cpuset='31' /></cputune> > <numatune><memory mode='strict' nodeset='0-7'/></numatune> > > In this case, the first part took more than 1700 seconds. 1-NUMA config > finishes in 1646 seconds. > > Hypervisor with 1-NUMA config finishes in 1470 seconds, the hypervisor with > 8-NUMA config finishes in 900 seconds. > > On Fri, Sep 14, 2018 at 02:06:26PM +0200, Lukas Hejtmanek wrote: > > Hello, > > > > I have cluster with AMD EPYC 7351 cpu. Two CPUs per node. I have performance > > 8-NUMA configuration: > > > > This is from hypervizor: > > [root@hde10 ~]# lscpu > > Architecture: x86_64 > > CPU op-mode(s): 32-bit, 64-bit > > Byte Order: Little Endian > > CPU(s): 64 > > On-line CPU(s) list: 0-63 > > Thread(s) per core: 2 > > Core(s) per socket: 16 > > Socket(s): 2 > > NUMA node(s): 8 > > Vendor ID: AuthenticAMD > > CPU family: 23 > > Model: 1 > > Model name: AMD EPYC 7351 16-Core Processor > > Stepping: 2 > > CPU MHz: 1800.000 > > CPU max MHz: 2400.0000 > > CPU min MHz: 1200.0000 > > BogoMIPS: 4800.05 > > Virtualization: AMD-V > > L1d cache: 32K > > L1i cache: 64K > > L2 cache: 512K > > L3 cache: 8192K > > NUMA node0 CPU(s): 0-3,32-35 > > NUMA node1 CPU(s): 4-7,36-39 > > NUMA node2 CPU(s): 8-11,40-43 > > NUMA node3 CPU(s): 12-15,44-47 > > NUMA node4 CPU(s): 16-19,48-51 > > NUMA node5 CPU(s): 20-23,52-55 > > NUMA node6 CPU(s): 24-27,56-59 > > NUMA node7 CPU(s): 28-31,60-63 > > > > I'm running one big virtual on this hypervizor - almost whole memory + all > > physical CPUs. > > > > This is what I'm seeing inside: > > > > root@zenon10:~# lscpu > > Architecture: x86_64 > > CPU op-mode(s): 32-bit, 64-bit > > Byte Order: Little Endian > > CPU(s): 32 > > On-line CPU(s) list: 0-31 > > Thread(s) per core: 1 > > Core(s) per socket: 4 > > Socket(s): 8 > > NUMA node(s): 8 > > Vendor ID: AuthenticAMD > > CPU family: 23 > > Model: 1 > > Model name: AMD EPYC 7351 16-Core Processor > > Stepping: 2 > > CPU MHz: 2400.000 > > BogoMIPS: 4800.00 > > Virtualization: AMD-V > > Hypervisor vendor: KVM > > Virtualization type: full > > L1d cache: 64K > > L1i cache: 64K > > L2 cache: 512K > > NUMA node0 CPU(s): 0-3 > > NUMA node1 CPU(s): 4-7 > > NUMA node2 CPU(s): 8-11 > > NUMA node3 CPU(s): 12-15 > > NUMA node4 CPU(s): 16-19 > > NUMA node5 CPU(s): 20-23 > > NUMA node6 CPU(s): 24-27 > > NUMA node7 CPU(s): 28-31 > > > > This is virtual node configuration: (i tried different numatune settings but > > it was still the same) > > > > <domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'> > > <name>one-55782</name> > > <vcpu><![CDATA[32]]></vcpu> > > <cputune> > > <shares>32768</shares> > > </cputune> > > <memory>507904000</memory> > > <os> > > <type arch='x86_64'>hvm</type> > > </os> > > <devices> > > <emulator><![CDATA[/usr/bin/kvm]]></emulator> > > <disk type='file' device='disk'> > > <source file='/opt/opennebula/var/datastores/108/55782/disk.0'/> > > <target dev='vda'/> > > <driver name='qemu' type='qcow2' cache='unsafe'/> > > </disk> > > <disk type='file' device='disk'> > > <source file='/opt/opennebula/var/datastores/108/55782/disk.1'/> > > <target dev='vdc'/> > > <driver name='qemu' type='raw' cache='unsafe'/> > > </disk> > > <disk type='file' device='disk'> > > <source file='/opt/opennebula/var/datastores/108/55782/disk.2'/> > > <target dev='vdd'/> > > <driver name='qemu' type='raw' cache='unsafe'/> > > </disk> > > <disk type='file' device='disk'> > > <source file='/opt/opennebula/var/datastores/108/55782/disk.3'/> > > <target dev='vde'/> > > <driver name='qemu' type='raw' cache='unsafe'/> > > </disk> > > <disk type='file' device='cdrom'> > > <source file='/opt/opennebula/var/datastores/108/55782/disk.4'/> > > <target dev='vdb'/> > > <readonly/> > > <driver name='qemu' type='raw'/> > > </disk> > > <interface type='bridge'> > > <source bridge='br0'/> > > <mac address='02:00:93:fb:3b:78'/> > > <target dev='one-55782-0'/> > > <model type='virtio'/> > > <filterref filter='no-arp-mac-spoofing'> > > <parameter name='IP' value='147.251.59.120'/> > > </filterref> > > </interface> > > </devices> > > <features> > > <pae/> > > <acpi/> > > </features> > > <!-- RAW data follows: --> > > <cpu mode='host-passthrough'><topology sockets='8' cores='4' threads='1'/><numa><cell cpus='0-3' memory='62000000' /><cell cpus='4-7' memory='62000000' /><cell cpus='8-11' memory='62000000' /><cell cpus='12-15' memory='62000000' /><cell cpus='16-19' memory='62000000' /><cell cpus='20-23' memory='62000000' /><cell cpus='24-27' memory='62000000' /><cell cpus='28-31' memory='62000000' /></numa></cpu> > > <cputune><vcpupin vcpu='0' cpuset='0' /><vcpupin vcpu='1' cpuset='2' /><vcpupin vcpu='2' cpuset='4' /><vcpupin vcpu='3' cpuset='6' /><vcpupin vcpu='4' cpuset='8' /><vcpupin vcpu='5' cpuset='10' /><vcpupin vcpu='6' cpuset='12' /><vcpupin vcpu='7' cpuset='14' /><vcpupin vcpu='8' cpuset='16' /><vcpupin vcpu='9' cpuset='18' /><vcpupin vcpu='10' cpuset='20' /><vcpupin vcpu='11' cpuset='22' /><vcpupin vcpu='12' cpuset='24' /><vcpupin vcpu='13' cpuset='26' /><vcpupin vcpu='14' cpuset='28' /><vcpupin vcpu='15' cpuset='30' /><vcpupin vcpu='16' cpuset='1' /><vcpupin vcpu='17' cpuset='3' /><vcpupin vcpu='18' cpuset='5' /><vcpupin vcpu='19' cpuset='7' /><vcpupin vcpu='20' cpuset='9' /><vcpupin vcpu='21' cpuset='11' /><vcpupin vcpu='22' cpuset='13' /><vcpupin vcpu='23' cpuset='15' /><vcpupin vcpu='24' cpuset='17' /><vcpupin vcpu='25' cpuset='19' /><vcpupin vcpu='26' cpuset='21' /><vcpupin vcpu='27' cpuset='23' /><vcpupin vcpu='28' cpuset='25' /><vcpupin vcpu='29' cpuset='27' /><vcpupin vcpu='30' cpuset='29' /><vcpupin vcpu='31' cpuset='31' /></cputune> > > <numatune><memory mode='preferred' nodeset='0'/></numatune>) > > <devices><serial type='pty'><target port='0'/></serial><console type='pty'><target type='serial' port='0'/></console><channel type='pty'><target type='virtio' name='org.qemu.guest_agent.0'/></channel></devices> > > <devices><hostdev mode='subsystem' type='pci' managed='yes'><source><address domain='0x0' bus='0x11' slot='0x0' function='0x1'/></source></hostdev></devices> > > > > <devices><controller type='pci' index='1' model='pci-bridge'/><controller type='pci' index='2' model='pci-bridge'/><controller type='pci' index='3' model='pci-bridge'/><controller type='pci' index='4' model='pci-bridge'/><controller type='pci' index='5' model='pci-bridge'/></devices> > > <metadata> > > <system_datastore><![CDATA[/opt/opennebula/var/datastores/108/55782]]> </system_datastore> > > </metadata> > > </domain> > > > > If I run e.g., spec2017 on the virtual, I can see: > > > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > > 1350 root 20 0 843136 830068 2524 R 78.1 0.2 513:16.16 bwaves_r_base.m > > 2456 root 20 0 804608 791264 2524 R 76.6 0.2 491:39.92 bwaves_r_base.m > > 4631 root 20 0 843136 829892 2344 R 75.8 0.2 450:16.04 bwaves_r_base.m > > 6441 root 20 0 802580 790212 2532 R 75.0 0.2 120:37.54 bwaves_r_base.m > > 7991 root 20 0 784676 772092 2576 R 75.0 0.2 387:15.39 bwaves_r_base.m > > 8142 root 20 0 843136 830044 2496 R 75.0 0.2 384:39.02 bwaves_r_base.m > > 8234 root 20 0 843136 830064 2524 R 75.0 0.2 99:04.48 bwaves_r_base.m > > 8578 root 20 0 749240 736604 2468 R 73.4 0.2 375:45.66 bwaves_r_base.m > > 9974 root 20 0 784676 771984 2468 R 73.4 0.2 348:01.36 bwaves_r_base.m > > 10396 root 20 0 802580 790264 2576 R 73.4 0.2 340:08.40 bwaves_r_base.m > > 12932 root 20 0 843136 830024 2480 R 73.4 0.2 288:39.76 bwaves_r_base.m > > 13113 root 20 0 784676 771864 2348 R 71.9 0.2 284:47.34 bwaves_r_base.m > > 13518 root 20 0 784676 762816 2540 R 71.9 0.2 276:31.58 bwaves_r_base.m > > 14443 root 20 0 784676 771984 2468 R 71.9 0.2 260:01.82 bwaves_r_base.m > > 12791 root 20 0 784676 772060 2544 R 70.3 0.2 291:43.96 bwaves_r_base.m > > 10544 root 20 0 843136 830068 2520 R 68.8 0.2 336:47.43 bwaves_r_base.m > > 15464 root 20 0 784676 762880 2608 R 60.9 0.2 239:19.14 bwaves_r_base.m > > 15487 root 20 0 784676 772048 2532 R 60.2 0.2 238:37.07 bwaves_r_base.m > > 16824 root 20 0 784676 772120 2604 R 55.5 0.2 212:10.92 bwaves_r_base.m > > 17255 root 20 0 843136 830012 2468 R 54.7 0.2 203:22.89 bwaves_r_base.m > > 17962 root 20 0 784676 772004 2488 R 54.7 0.2 188:26.07 bwaves_r_base.m > > 17505 root 20 0 843136 830068 2520 R 53.1 0.2 198:04.25 bwaves_r_base.m > > 27767 root 20 0 784676 771860 2344 R 52.3 0.2 592:25.95 bwaves_r_base.m > > 24458 root 20 0 843136 829888 2344 R 50.8 0.2 658:23.70 bwaves_r_base.m > > 30746 root 20 0 747376 735160 2604 R 43.0 0.2 556:47.67 bwaves_r_base.m > > > > The CPU TIME should be roughly the same but huge differences are obvious. > > > > This is what I see on the hypervizor: > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > > 18201 oneadmin 20 0 474.0g 473.3g 1732 S 2459 94.0 33332:54 kvm > > 369 root 20 0 0 0 0 R 100.0 0.0 768:12.85 kswapd1 > > 368 root 20 0 0 0 0 R 94.1 0.0 869:05.61 kswapd0 > > > > i.e., kswapd is eating whole CPU. Swap is turned off. > > > > [root@hde10 ~]# free > > total used free shared buff/cache available > > Mem: 528151432 503432580 1214048 34740 23504804 21907800 > > Swap: 0 0 0 > > > > Hypervisor is > > [root@hde10 ~]# cat /etc/redhat-release > > CentOS Linux release 7.5.1804 (Core) > > > > qemu-kvm-1.5.3-156.el7_5.5.x86_64 > > > > Virtual is Debian 9. > > > > > > Moreover, I'm using this type of disks for virtuals: > > <disk type='file' device='disk'> > > <source file='/opt/opennebula/var/datastores/108/55782/disk.3'/> > > <target dev='vde'/> > > <driver name='qemu' type='raw' cache='unsafe'/> > > </disk> > > > > If I keep cache='unsafe' and if I run iozone test on really big files (e.g., > > 8x 100GB), I can see huge cache pressure on the hypervizor - all 8 kswapd are > > running on 100 % percent and slowing things down. The disk under datastore is > > NVME SSD Intel 4500. > > > > If I set cache='none', kswaps are on idle, disk writes are pretty fast, > > however, with 8-NUMA configuration, writes slow down to less than 10MB/s as > > soon as the size of written data is roughly the same as memory size in the virtual > > node. iozone has 100 % CPU usage thereafter and it seems that it is traversing page > > lists. If I do the same with 1-NUMA configuration, everything is ok except > > performance penalty about 25 %. > > > > -- > > Lukáš Hejtmánek > > > > Linux Administrator only because > > Full Time Multitasking Ninja > > is not an official job title > > -- > Lukáš Hejtmánek > > Linux Administrator only because > Full Time Multitasking Ninja > is not an official job title -- Lukáš Hejtmánek Linux Administrator only because Full Time Multitasking Ninja is not an official job title _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
