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To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
cc: linux-kernel@vger.kernel.org
Subject: Markers in (non-module) kernel code?
From: "Theodore Ts'o" <tytso@mit.edu>
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I've been playing with adding some markers into ext4 to see if they
could be useful in solving some problems along with Systemtap.  It
appears, though, that as of 2.6.27-rc8, markers defined in code which is
compiled directly into the kernel (i.e., not as modules) don't show up
in Module.markers:

kvm_trace_entryexit	arch/x86/kvm/kvm-intel	%u %p %u %u %u %u %u %u
kvm_trace_handler	arch/x86/kvm/kvm-intel	%u %p %u %u %u %u %u %u
kvm_trace_entryexit	arch/x86/kvm/kvm-amd	%u %p %u %u %u %u %u %u
kvm_trace_handler	arch/x86/kvm/kvm-amd	%u %p %u %u %u %u %u %u

(Note the lack of any of the kernel_sched_* markers, and the markers I
added for ext4_* and jbd2_* are missing as wel.)

Systemtap apparently depends on in-kernel trace_mark being recorded in
Module.markers, and apparently it's been claimed that it used to be
there.  Is this a bug in systemtap, or in how Module.markers is getting
built?   And is there a file that contains the equivalent information
for markers located in non-modules code?

Thanks, regards,

						- Ted

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