[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Performance issues with /gnu/store in virtual machines
From: |
Christopher Baines |
Subject: |
Performance issues with /gnu/store in virtual machines |
Date: |
Thu, 17 Aug 2017 21:05:47 +0100 |
Hey,
So I was trying out using VMs created through Guix for more things,
particularly as they can be run as part of derivations, e.g. the system
tests for Guix.
However, I'm seeing anything that does I/O performing very poorly
compared with the host system. See the system call profiles from strace
below, for the following command:
strace -c find /gnu/store/*-guile* -name guile | wc -l
Is anyone else having difficulties with this, or have any experience
with performance tuning for the software in use here?
Thanks,
Chris
On the host system, I see the following performance:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
76.23 0.001286 0 31978 fcntl
10.20 0.000172 0 6974 getdents
7.53 0.000127 0 18673 newfstatat
3.32 0.000056 0 14208 close
1.60 0.000027 0 3872 fstat
1.13 0.000019 0 3853 openat
0.00 0.000000 0 20 read
0.00 0.000000 0 4 write
0.00 0.000000 0 69 50 open
0.00 0.000000 0 6 6 stat
0.00 0.000000 0 21 mmap
0.00 0.000000 0 8 mprotect
0.00 0.000000 0 33 brk
0.00 0.000000 0 2 1 ioctl
0.00 0.000000 0 1 1 access
0.00 0.000000 0 1 execve
0.00 0.000000 0 1 uname
0.00 0.000000 0 1 fchdir
0.00 0.000000 0 1 arch_prctl
------ ----------- ----------- --------- --------- ----------------
100.00 0.001687 79726 58 total
Within the VM, I see the following performance:
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
59.83 0.851601 46 18673 newfstatat
13.56 0.193014 50 3853 openat
10.88 0.154935 22 6974 getdents
7.95 0.113196 8 14208 close
4.00 0.056956 15 3872 fstat
3.58 0.050908 2 31978 fcntl
0.14 0.002051 66 31 12 open
0.02 0.000232 12 20 read
0.01 0.000199 7 30 brk
0.01 0.000107 18 6 6 stat
0.01 0.000076 4 21 mmap
0.00 0.000045 6 8 mprotect
0.00 0.000030 8 4 write
0.00 0.000018 18 1 1 access
0.00 0.000006 3 2 1 ioctl
0.00 0.000004 4 1 execve
0.00 0.000003 3 1 uname
0.00 0.000003 3 1 fchdir
0.00 0.000001 1 1 arch_prctl
------ ----------- ----------- --------- --------- ----------------
100.00 1.423385 79685 20 total
pgpIf3h7loL4H.pgp
Description: OpenPGP digital signature
- Performance issues with /gnu/store in virtual machines,
Christopher Baines <=