Messages in this thread Patches in this message | | | Date | Fri, 3 Oct 2008 15:54:36 -0400 | From | Mathieu Desnoyers <> | Subject | [PATCH] Marker depmod fix core kernel list |
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* Theodore Ts'o (tytso@mit.edu) wrote: > > 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, >
I think the problem comes from this patch : commit d35cb360c29956510b2fe1a953bd4968536f7216 "markers: fix duplicate modpost entry"
Especially :
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index a07f91a..8f038e6 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1992,7 +1992,8 @@ static void read_markers(const char *fname) mod->skip = 1; }
- add_marker(mod, marker, fmt); + if (!mod->skip) + add_marker(mod, marker, fmt); } return; fail: Here is a fix that should take care if this problem. Given I am not the modpost expert, let's see if I can get an ACK from Sam.
Thanks for the bug report!
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Theodore Ts'o <tytso@mit.edu> CC: David Smith <dsmith@redhat.com> CC: Roland McGrath <roland@redhat.com> CC: Sam Ravnborg <sam@ravnborg.org> CC: Wenji Huang <wenji.huang@oracle.com> CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com> --- scripts/mod/modpost.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Index: linux-2.6-lttng/scripts/mod/modpost.c =================================================================== --- linux-2.6-lttng.orig/scripts/mod/modpost.c 2008-10-03 15:42:00.000000000 -0400 +++ linux-2.6-lttng/scripts/mod/modpost.c 2008-10-03 15:42:59.000000000 -0400 @@ -1986,11 +1986,13 @@ static void read_markers(const char *fna mod = find_module(modname); if (!mod) { - if (is_vmlinux(modname)) - have_vmlinux = 1; mod = new_module(NOFAIL(strdup(modname))); mod->skip = 1; } + if (is_vmlinux(modname)) { + have_vmlinux = 1; + mod->skip = 0; + } if (!mod->skip) add_marker(mod, marker, fmt); -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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