Re: Facing problem while patching LTTng 0.9.5 with linux kernel 2.6.21

* Srinivasa Reddy ([email protected]) wrote:
> Hi Mathieu,
> 
> Thanks. LTTV working fine with ltt-control 0.42 version.
> 
> I have one more question. When I stop the trace by giving the following
> command, it's giving "LTT : cpu : 2351 events lost in cpu channel (cpu
> 0)."
> 
> Please have a look at the below messages.
> 
> /home/sreddy # lttctl -n trace42 -R
> Linux Trace Toolkit Trace Control 0.42-16072007
> 
> Controlling trace : trace42
> 
> ltt_control : trace trace42
> ltt_control : trace trace42
> /home/sreddy # LTT : cpu : 2351 events lost in cpu channel (cpu 0).
> 
> /home/sreddy #
> 
> 
> Could you please tell me why it's missing those events?
> 

What architecture are you taking your trace from again ? ARM ? x86 ?

If it is x86, try disabling the "Locking" facility in the kernel
menuconfig, Instrumentation Support.

If it is ARM, it's a problem with the timer interrupt instrumentation.
You loose events normally written with write seqlock held. It will be
fixed in the next versions. It will only restrain you from seeing the
jiffies update events.

Mathieu

> Regards,
> Srinivas.
> 
> -----Original Message-----
> From: Mathieu Desnoyers [mailto:[email protected]] 
> Sent: Thursday, July 26, 2007 8:25 PM
> To: Srinivasa Reddy
> Cc: [email protected]
> Subject: Re: [Ltt-dev] Facing problem while patching LTTng 0.9.5 with
> linux kernel 2.6.21
> 
> * Srinivasa Reddy ([email protected]) wrote:
> > Hi Mathieu,
> > 
> > I am using the lttv version of 0.8.82 which is compatible for 2.6.21
> > kernel.
> > 
> 
> http://ltt.polymtl.ca/svn/ltt/branches/poly/doc/developer/lttng-lttv-com
> patibility.html
> "ltt-control 0.42 fixes a bug with LTTng lseek event."
> 
> Please apply the following patch to ltt-control and it should work. Note
> that you have to reinstall the ltt-control package with make install.
> 
> If you want to test it quickly, you can edit the eventdefs/fs.xml file
> directly in your trace directory.
> 
> The warnings about facility checksums are expected. The ground is moving
> fast in this area (facilities are completely going away in the upcoming
> release).
> 
> Mathieu
> 
> --- facilities/fs.xml	(revision 2537)
> +++ facilities/fs.xml	(working copy)
> @@ -74,7 +74,7 @@
>    <event name="lseek">
>      <description>Seek a file descriptor</description>
>      <field name="fd"> <description>File descriptor</description>
> <uint/> </field>
> -    <field name="offset"> <description>Number of bytes to
> write</description> <off_t/> </field>
> +    <field name="offset"> <description>Number of bytes to
> write</description> <long/> </field>
>      <field name="origin"> <description>Number of bytes to
> write</description> <uint/> </field>
>    </event>
>  
> 
> > So when I try to open the trace generated, it has given the following
> > error messages: 
> >
> ************************************************************************
> > *
> > 
> >
> test-devsys:/home/rrao/NFS/NFS_test/home/sreddy/LinuxTraceToolkitViewer-
> > 0.8.82-09042007/lttv/lttv# ./lttv-gui
> > ** Message: statistics viewer : background computation data ready.
> > ** Message: statistics viewer : background computation data ready.
> > 
> > ** (lt-lttv.real:6548): WARNING **: Facility checksum mismatch for
> > facility core : kernel 0xB96B8A8D vs XML 0x1212DF53
> > 
> > 
> > ** (lt-lttv.real:6548): WARNING **: Facility checksum mismatch for
> > facility mm : kernel 0xE2F8E03B vs XML 0x5DD3900C
> > 
> > 
> > ** (lt-lttv.real:6548): WARNING **: Facility checksum mismatch for
> > facility kernel_arch : kernel 0x3D22856 vs XML 0xFCD2247B
> > 
> > 
> > ** (lt-lttv.real:6548): WARNING **: Facility checksum mismatch for
> > facility list : kernel 0x55E7EB91 vs XML 0x4DA5EA7A
> > 
> > 
> > ** (lt-lttv.real:6548): WARNING **: Facility checksum mismatch for
> > facility net : kernel 0xF3E69EB3 vs XML 0x4BF8A6A8
> > 
> > 
> > ** (lt-lttv.real:6548): WARNING **: Facility checksum mismatch for
> > facility kernel : kernel 0x1DDF2BD3 vs XML 0x58E1793A
> > 
> > 
> > ** (lt-lttv.real:6548): WARNING **: Facility checksum mismatch for
> > facility fs : kernel 0xEC4B78E1 vs XML 0x7D72FF54
> > 
> > 
> > ** ERROR **: Kernel/LTTV event size differs for event fs.lseek: kernel
> > 16, LTTV 12
> > aborting...
> > ./lttv-gui: line 10:  6548 Aborted                 $LTTV_CMD.real -m
> > guievents -m guifilter -m guicontrolflow -m guistatistics -m
> > guitracecontrol $*
> >
> test-devsys:/home/rrao/NFS/NFS_test/home/sreddy/LinuxTraceToolkitViewer-
> > 0.8.82-09042007/lttv/lttv#   
> > 
> >
> ************************************************************************
> > ***
> > 
> > Please let me know about this.
> > 
> > -Srinivas.
> > 
> > 
> > 
> > 
> > -----Original Message-----
> > From: Mathieu Desnoyers [mailto:[email protected]] 
> > Sent: Thursday, July 26, 2007 7:45 PM
> > To: Srinivasa Reddy
> > Cc: [email protected]
> > Subject: Re: [Ltt-dev] Facing problem while patching LTTng 0.9.5 with
> > linux kernel 2.6.21
> > 
> > * Srinivasa Reddy ([email protected]) wrote:
> > > Hi Mathieu,
> > > 
> > > Good news.. Now I am able to generate some trace data.
> > > The problem was mounting debugfs.
> > > So when I gave "mount /mnt/debugfs" command after booting, then it
> > > started generating the trace information.
> > > 
> > > But unfortunately the viewer gave the following bundle of errors. 
> > > 
> > > ************************************************************
> > > 
> > > test-devsys:/home/rrao/NFS/NFS_test/home/sreddy# lttv-gui
> > > 
> > > ** (lttv.real:9515): WARNING **: parse_trace_header error
> > > 
> > > ** (lttv.real:9515): WARNING **: parse_trace_header error
> > > 
> > > ** (lttv.real:9515): WARNING **: parse_trace_header error
> > > 
> > > ** (lttv.real:9515): WARNING **: parse_trace_header error
> > > 
> > > ** (lttv.real:9515): WARNING **: parse_trace_header error
> > > 
> > > ** (lttv.real:9515): WARNING **: parse_trace_header error
> > > 
> > > ** ERROR **: Trace /home/rrao/NFS/NFS_test/home/sreddy/trace1 has no
> > > facility tracefile
> > > aborting...
> > > /usr/bin/lttv-gui: line 10:  9515 Aborted
> > $LTTV_CMD.real
> > > -m guievents -m guifilter -m guicontrolflow -m guistatistics -m
> > > guitracecontrol $*
> > > 
> > > 
> > > **********************************************************
> > > 
> > > So is the data generated is proper or something is missing in the
> > data.
> > > If you want is will send those generated files.
> > > Please let me know about this.
> > > 
> > 
> > Please go back in this email thread and repeat the steps I pointed to.
> I
> > suspect that you use the wrong LTTV version. Please provide the
> listings
> > I have requested earlier (listing of trace directory at least) so I
> can
> > help you further.
> > 
> > Mathieu
> > 
> > > Regards,
> > > Srinivas.
> > > 
> > 
> > -- 
> > Mathieu Desnoyers
> > Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
> > OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE
> > 9A68
> > 
> 
> -- 
> Mathieu Desnoyers
> Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
> OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE
> 9A68
> 

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68