Re: [PATCH 0/2] KernelShark2.0: Use libtracefs APIs to access tracefs

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 6.03.20 г. 22:13 ч., Steven Rostedt wrote:
On Fri,  6 Mar 2020 11:29:00 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:

From: "Tzvetomir (VMware)  Stoyanov" <tz.stoyanov@xxxxxxxxx>

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?

Hi Steven,

Yes it will fail to initialize in the guest's file if it does not contain kvm events and this is normal. The plugin only draws the additional graphical elements associated with kvm_entry and kvm_exit events. So nothing will be plotted on top of the guest data.

The plugin itself has nothing to do with the synchronization of the timestamps.

Thanks!
Yordan


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




[Index of Archives]     [Linux USB Development]     [Linux USB Development]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux