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From: Steven Rostedt <>
To: "Tzvetomir Stoyanov (VMware)" <>
Cc:, Yordan Karadzhov <>
Subject: Re: [PATCH 0/2] KernelShark2.0: Use libtracefs APIs to access tracefs
Date: Fri, 6 Mar 2020 15:13:56 -0500
Message-ID: <20200306151356.4bbeef14@gandalf.local.home> (raw)
In-Reply-To: <>

On Fri,  6 Mar 2020 11:29:00 +0200
"Tzvetomir Stoyanov (VMware)" <> wrote:

> From: "Tzvetomir (VMware)  Stoyanov" <>
> The tracefs library provides APIs for accessing files from tracefs.
> The library is part of trace-cmd, it is installed as part of trace-cmd
> installation. KernelShark uses some of those APIs and must be linked with
> the library
> Tzvetomir (VMware)  Stoyanov (2):
>   KernelShark2.0: Link KernelShark to libtracefs
>   KernelShark2.0: Use libtracefs APIs to access tracefs

I added these patches to the latest kernelshark-2.0 and it still doesn't
work for me. I did a little debugging, and noticed that it fails while
reading the guest trace.dat file with:

plugin "kvm_combo" failed to initialize on stream /tmp/trace-host-Fedora21.

It seems to require that the guest trace.dat file has kvm events?

Note, as I build my guest kernel with a make localmodconfig, which disables
all modules that are not necessary to boot the box, there is no kvm events
there. I can see why the host may need them, but not the guest. I'll
rebuild my guest kernel with kvm events and see if that solves this (but
that shouldn't be the case).

-- Steve

  parent reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-06  9:29 Tzvetomir Stoyanov (VMware)
2020-03-06  9:29 ` [PATCH 1/2] KernelShark2.0: Link KernelShark to libtracefs Tzvetomir Stoyanov (VMware)
2020-03-06  9:29 ` [PATCH 2/2] KernelShark2.0: Use libtracefs APIs to access tracefs Tzvetomir Stoyanov (VMware)
2020-03-06 20:13 ` Steven Rostedt [this message]
2020-03-06 22:34   ` [PATCH 0/2] " Steven Rostedt
2020-03-09  9:17     ` Yordan Karadzhov (VMware)
2020-03-09 15:44       ` Steven Rostedt
2020-03-09 16:30         ` Steven Rostedt
2020-03-09  9:10   ` Yordan Karadzhov (VMware)

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