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Message-ID: <51ADA785.4000904@hitachi.com>
Date: Tue, 04 Jun 2013 17:38:29 +0900
From: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@...achi.com>
To: linux-kernel@...r.kernel.org
Cc: "H. Peter Anvin" <hpa@...or.com>, Gleb Natapov <gleb@...hat.com>,
David Sharp <dhsharp@...gle.com>,
Marcelo Tosatti <mtosatti@...hat.com>,
Steven Rostedt <rostedt@...dmis.org>,
Hidehiro Kawai <hidehiro.kawai.ez@...achi.com>,
Ingo Molnar <mingo@...hat.com>, yrl.pp-manager.tt@...achi.com,
Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
Thomas Gleixner <tglx@...utronix.de>
Subject: [EXAMPLE] tools: a tool for merging trace data of a guest and a host
This tool merges trace data of a guest and a host in chronological
order. Restrictions of this tool is as follows:
- one guest (not for multiple guests)
- stable TSC (not backward TSC)
- synchronized TSC
- unchanged TSC offset (the guest does not execute write_TSC)
- How to use
1. [host] Enable kvm_write_tsc_offset before booting a guest
# cd /sys/kernel/debug/tracing/instances
# mkdir tsc_offset
# cd tsc_offset
# echo x86-tsc > trace_clock
# echo 1 > events/kvm/kvm_write_tsc_offset/enable
2. [host] Enable events you want
Note: I recommend to enable kvm_exit/entry events.
# cd /sys/kernel/debug/tracing
# echo kvm_entry >> set_event
# echo kvm_exit >> set_event
# [snip]
# echo x86-tsc > trace_clock
3. [host] Boot the guest
4. [guest] Enable events you want
# cd /sys/kernel/debug/tracing
# echo sched_wakeup >> set_event
# echo sched_switch >> set_event
# [snip]
# echo x86-tsc > trace_clock
5. [guest] Run programs
6. [guest/host] Get trace data
# echo 0 > tracing_on
# cat trace > /home/yourdir/log/guest_trace.txt (for the guest)
(cat trace > /home/yourdir/log/host_trace.txt (for the host))
# scp [host_IP]:/home/yourdir/log/guest_trace.txt (only for the guest)
7. [host] Get next TSC offset
# cat /sys/kernel/debug/tracing/instances/tsc_offset/trace
qemu-kvm-22089 [000] d...4300151845072: kvm_write_tsc_offset:
previous 0 next 18446739773557710924
8. [host] Run this tool with the next TSC offset for -t option.
$ ./trace-merge.pl -g ~/log/guest_trace.txt -h ~/log/host_trace.txt \
-t 18446739773557710924
h qemu-kvm-2687 [003] d...50550079203669: kvm_exit: [detail]
h qemu-kvm-2687 [003] d...50550079206816: kvm_entry: [detail]
g comm-3826 [000] d.h.50550079226331: sched_wakeup: [detail]
h qemu-kvm-2687 [003] d...50550079240656: kvm_exit: [detail]
h qemu-kvm-2687 [003] d...50550079243467: kvm_entry: [detail]
h qemu-kvm-2687 [003] d...50550079256103: kvm_exit: [detail]
h qemu-kvm-2687 [003] d...50550079268391: kvm_entry: [detail]
g comm-3826 [000] d...50550079279266: sched_switch: [detail]
h qemu-kvm-2687 [003] d...50550079280829: kvm_exit: [detail]
h qemu-kvm-2687 [003] d...50550079286028: kvm_entry: [detail]
|
\----guest/host
Thanks,
--
Yoshihiro YUNOMAE
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: yoshihiro.yunomae.ez@...achi.com
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