1PERF-KVM(1) perf Manual PERF-KVM(1)
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6 perf-kvm - Tool to trace/measure kvm guest os
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9 perf kvm [--host] [--guest] [--guestmount=<path>
10 [--guestkallsyms=<path> --guestmodules=<path> | --guestvmlinux=<path>]]
11 {top|record|report|diff|buildid-list} [<options>]
12 perf kvm [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path>
13 | --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat} [<options>]
14 ´perf kvm stat [record|report|live] [<options>]
15
17 There are a couple of variants of perf kvm:
18 ´perf kvm [options] top <command>´ to generates and displays
20 a performance counter profile of guest os in realtime
21 of an arbitrary workload.
22 ´perf kvm record <command>´ to record the performance counter profile
24 of an arbitrary workload and save it into a perf data file. We set the
25 default behavior of perf kvm as --guest, so if neither --host nor --guest
26 is input, the perf data file name is perf.data.guest. If --host is input,
27 the perf data file name is perf.data.kvm. If you want to record data into
28 perf.data.host, please input --host --no-guest. The behaviors are shown as
29 following:
30 Default(´´) -> perf.data.guest
31 --host -> perf.data.kvm
32 --guest -> perf.data.guest
33 --host --guest -> perf.data.kvm
34 --host --no-guest -> perf.data.host
35 ´perf kvm report´ to display the performance counter profile information
37 recorded via perf kvm record.
38 ´perf kvm diff´ to displays the performance difference amongst two perf.data
40 files captured via perf record.
41 ´perf kvm buildid-list´ to display the buildids found in a perf data file,
43 so that other tools can be used to fetch packages with matching symbol tables
44 for use by perf report. As buildid is read from /sys/kernel/notes in os, then
45 if you want to list the buildid for guest, please make sure your perf data file
46 was captured with --guestmount in perf kvm record.
47 ´perf kvm stat <command>´ to run a command and gather performance counter
49 statistics.
50 Especially, perf ´kvm stat record/report´ generates a statistical analysis
51 of KVM events. Currently, vmexit, mmio and ioport events are supported.
52 ´perf kvm stat record <command>´ records kvm events and the events between
53 start and end <command>.
54 And this command produces a file which contains tracing results of kvm
55 events.
56 ´perf kvm stat report´ reports statistical data which includes events
58 handled time, samples, and so on.
59 ´perf kvm stat live´ reports statistical data in a live mode (similar to
61 record + report but with statistical data updated live at a given display
62 rate).
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65 -i, --input=<path>
66 Input file name.
67 -o, --output=<path>
69 Output file name.
70 --host
72 Collect host side performance profile.
73 --guest
75 Collect guest side performance profile.
76 --guestmount=<path>
78 Guest os root file system mount directory. Users mounts guest os
79 root directories under <path> by a specific filesystem access
80 method, typically, sshfs. For example, start 2 guest os. The one’s
81 pid is 8888 and the other’s is 9999. #mkdir /guestmount;
82 cd/guestmount #sshfs -o allow_other,direct_io -p 5551 localhost:/
83 8888/ #sshfs -o allow_other,direct_io -p 5552 localhost:/ 9999/
84 #perf kvm --host --guest --guestmount=~/guestmount top
85 --guestkallsyms=<path>
87 Guest os /proc/kallsyms file copy. perf kvm´ reads it to get guest
88 kernel symbols. Users copy it out from guest os.
89 --guestmodules=<path>
91 Guest os /proc/modules file copy. perf kvm´ reads it to get guest
92 kernel module information. Users copy it out from guest os.
93 --guestvmlinux=<path>
95 Guest os kernel vmlinux.
96 -v, --verbose
98 Be more verbose (show counter open errors, etc).
99
101 --vcpu=<value>
102 analyze events which occur on this vcpu. (default: all vcpus)
103 --event=<value>
105 event to be analyzed. Possible values: vmexit, mmio, ioport.
106 (default: vmexit)
107 -k, --key=<value>
109 Sorting key. Possible values: sample (default, sort by samples
110 number), time (sort by average time).
111 -p, --pid=
113 Analyze events only for given process ID(s) (comma separated list).
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116 -d, --display
117 Time in seconds between display updates
118 -m, --mmap-pages=
120 Number of mmap data pages (must be a power of two) or size
121 specification with appended unit character - B/K/M/G. The size is
122 rounded up to have nearest pages power of two value.
123 -a, --all-cpus
125 System-wide collection from all CPUs.
126 -p, --pid=
128 Analyze events only for given process ID(s) (comma separated list).
129 --vcpu=<value>
131 analyze events which occur on this vcpu. (default: all vcpus)
132 --event=<value>
134 event to be analyzed. Possible values: vmexit, mmio, ioport.
135 (default: vmexit)
136 -k, --key=<value>
138 Sorting key. Possible values: sample (default, sort by samples
139 number), time (sort by average time).
140 --duration=<value>
142 Show events other than HLT that take longer than duration usecs.
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145 perf-top(1), perf-record(1), perf-report(1), perf-diff(1), perf-
146 buildid-list(1), perf-stat(1)
147perf 06/18/2019 PERF-KVM(1)