* Harsh Bora (ha...@linux.vnet.ibm.com) wrote: > On 01/10/2012 02:36 PM, Harsh Bora wrote: >> On 01/10/2012 12:47 PM, Mathieu Desnoyers wrote: >>> * Harsh Bora (ha...@linux.vnet.ibm.com) wrote: >>>> On 01/10/2012 05:44 AM, Mathieu Desnoyers wrote: >>>>> * Harsh Bora (ha...@linux.vnet.ibm.com) wrote: >>>>>> On 01/09/2012 09:31 PM, Mathieu Desnoyers wrote: >>>>>>> * Harsh Prateek Bora (ha...@linux.vnet.ibm.com) wrote: >>>>>>>> Existing simple trace can log upto 6 args per trace event and >>>>>>>> does not >>>>>>>> support strings in trace record format. Introducing new trace >>>>>>>> format as >>>>>>>> discussed earlier on list to support variable number/size of >>>>>>>> arguments. >>>>>>>> (Ref: >>>>>>>> http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg03426.html) >>>>>>>> >>>>>>>> Basic testing of this patch is successful. Stress testing not yet >>>>>>>> done. >>>>>>>> >>>>>>>> Apply patches, then run: >>>>>>>> >>>>>>>> make distclean >>>>>>>> ./configure with --enable-trace-backend=simple >>>>>>>> make >>>>>>>> sudo make install >>>>>>>> >>>>>>>> Sample tracelog showing strings support: >>>>>>>> [harsh@harshbora v9fs]$ scripts/simpletrace.py trace-events >>>>>>>> trace-23261 >>>>>>>> v9fs_version 0.000 tag=65535 id=100 msize=8192 version=9P2000.L >>>>>>>> v9fs_version_return 17.530 tag=65535 id=100 msize=8192 >>>>>>>> version=9P2000.L >>>>>>>> v9fs_attach 180.121 tag=1 id=104 fid=0 afid=18446744073709551615 >>>>>>>> uname=nobody aname= >>>>>>>> >>>>>>>> >>>>>>>> Note: LTTng ust backend is broken in upstream qemu, therefore >>>>>>>> tracetool.py >>>>>>>> doesnt support ust backend as of now. IIUC, ust's trace event >>>>>>>> APIs are under >>>>>>>> development and not yet stable. >>>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> FYI, the LTTng-UST TRACEPOINT_EVENT API is very much stable as of >>>>>>> now. >>>>>>> Even though we are still in LTTng-UST 2.0 prereleases, the fact >>>>>>> that we >>>>>>> started the round of discussions on this API last summer makes us >>>>>>> confident that from this point on we should not have to change it. >>>>>>> >>>>>>> Moreover, I would like to know if the old UST 0.x (0.16 is the >>>>>>> latest) >>>>>>> is broken wrt qemu, or if this is just for LTTng-2.0 UST support ? >>>>>>> UST 0.x instrumentation is not supposed to have broken wrt qemu. >>>>>>> >>>>>> >>>>>> Hi, >>>>>> Thanks for an early response. I had tried building with ust 0.16 >>>>>> and it >>>>>> gives compilation errors, specially for trace events with 'void' >>>>>> argument: >>>>>> >>>>>> CC osdep.o >>>>>> In file included from osdep.c:49: >>>>>> trace.h: In function ‘__trace_ust_slavio_misc_update_irq_raise’: >>>>>> trace.h:277: error: ‘void’ must be the only parameter >>>>>> trace.h:277: error: expected expression before ‘)’ token >>>>>> trace.h:277: error: too many arguments to function ‘(void (*)(void >>>>>> *))__tp_it_func’ >>>>>> trace.h: At top level: >>>>>> trace.h:277: error: ‘void’ must be the only parameter >>>>>> trace.h:277: error: ‘void’ must be the only parameter >>>>>> In file included from osdep.c:49: >>>>>> trace.h: In function ‘__trace_ust_slavio_misc_update_irq_lower’: >>>>>> trace.h:280: error: ‘void’ must be the only parameter >>>>>> trace.h:280: error: expected expression before ‘)’ token >>>>>> trace.h:280: error: too many arguments to function ‘(void (*)(void >>>>>> *))__tp_it_func’ >>>>>> >>>>>> >>>>>> I am not sure which interface is supposed to be used for void >>>>>> arguments >>>>>> in ust 0.16. >>>>> >>>>> Looking at scripts/tracetool: >>>>> >>>>> linetoh_ust() >>>>> { >>>>> local name args argnames >>>>> name=$(get_name "$1") >>>>> args=$(get_args "$1") >>>>> argnames=$(get_argnames "$1", ",") >>>>> >>>>> cat<<EOF >>>>> DECLARE_TRACE(ust_$name, TP_PROTO($args), TP_ARGS($argnames)); >>>>> #define trace_$name trace_ust_$name >>>>> EOF >>>>> } >>>>> >>>>> for those tracepoints with argument "void", DECLARE_TRACE_NOARGS should >>>>> be used for UST 0.16. Similar for: >>>>> >>>>> DEFINE_TRACE(ust_$name); -> DEFINE_TRACE_NOARGS(ust_$name); >>>>> >>>> >>>> I had tried with _NOARGS variants initially by manually changing the >>>> auto-generated code like this: >>>> >>>> In trace.h: >>>> >>>> DECLARE_TRACE_NOARGS(ust_slavio_misc_update_irq_raise); >>>> #define trace_slavio_misc_update_irq_raise >>>> trace_ust_slavio_misc_update_irq_raise >>>> >>>> In trace.c: >>>> >>>> DEFINE_TRACE_NOARGS(ust_slavio_misc_update_irq_raise); >>>> >>>> static void ust_slavio_misc_update_irq_raise_probe() >>>> { >>>> trace_mark(ust, slavio_misc_update_irq_raise); >>>> } >>>> >>>> >>>> However, it still gave error like this: >>>> >>>> [harsh@harshbora v9fs]$ make >>>> CC osdep.o >>>> cc1: warnings being treated as errors >>>> In file included from osdep.c:49: >>>> trace.h:277: error: data definition has no type or storage class >>>> trace.h:277: error: type defaults to ‘int’ in declaration of >>>> ‘DECLARE_TRACE_NOARGS’ >>>> trace.h:277: error: parameter names (without types) in function >>>> declaration >>>> >>>> >>>> It will be great if you can provide a sample code (to be auto-generated) >>>> required for a trace-event with void argument. >>> >>> Ah, right, now I remember that I only left DEFINE_TRACE and DECLARE_TRACE >>> as backward compatibility in UST 0.x, and did only add the "_NOARGS" to >>> the backward compatibility macros with an added underscore prefix. >>> >>> If you really just want to have compatibility with UST 0.16, changing the >>> minimum of things compared with what you currently have, I would >>> recommend to use: >>> >>> in trace.h: >>> _DECLARE_TRACEPOINT_NOARGS(ust_slavio_misc_update_irq_raise) >>> #define trace_slavio_misc_update_irq_raise >>> trace_ust_slavio_misc_update_irq_raise >>> >>> in trace.c: >>> DEFINE_TRACE(ust_slavio_misc_update_irq_raise); >>> >>> static void ust_slavio_misc_update_irq_raise_probe(void) >>> { >>> trace_mark(ust, slavio_misc_update_irq_raise, UST_MARKER_NOARGS); >>> } >>> >>> Let me know how this works for you, >> >> Thanks for the help, I wrote the python code to auto-generate the same >> for events with void arg. However, after doing make, it says: >> >> trace.o:(__ust_markers+0x4a08): undefined reference to >> `__ust_marker_empty_function' >> trace.o:(__ust_markers+0x4a60): undefined reference to >> `ust_marker_probe_cb' >> trace.o:(__ust_markers+0x4a68): undefined reference to >> `__ust_marker_empty_function' >> trace.o:(__ust_markers+0x4ac0): undefined reference to >> `ust_marker_probe_cb' >> >> I have tested using both: >> 1) ust 0.15 with urcu 0.6. >> 2) ust 0.16 with urcu 0.6.6 >> >> Any idea, why this error ? > > Ok, I got it (Thanks Aneesh). It required this change in configure: > > diff --git a/configure b/configure > index 0ea8634..40a18d8 100755 > --- a/configure > +++ b/configure > @@ -2495,7 +2495,8 @@ if test "$trace_backend" = "ust"; then > int main(void) { return 0; } > EOF > if compile_prog "" "" ; then > - LIBS="-lust $LIBS" > + LIBS="-lust -lurcu-bp $LIBS" > + libs_qga+="-lust -lurcu-bp" > else
I'm glad it works for you for 0.x. Please note that lttng-ust 2.0 will not require that many tweaks: I've made sure the instrumentation is more straightforward. Thanks, Mathieu > > regards, > Harsh > >> >> - Harsh >> >>> >>> Best regards, >>> >>> Mathieu >>> >>>> >>>> - Harsh >>>> >>>>>> Moreover, if ust 2.0 uses different interfaces, we might >>>>>> want to use the latest one. >>>>> >>>>> Note that this kind of special-case won't be needed with LTTng-UST 2.0 >>>>> TRACEPOINT_EVENT. In place of DECLARE_TRACE, one would use: >>>>> >>>>> TRACEPOINT_EVENT(qemu_kvm, $name, >>>>> TP_ARGS($args), >>>>> TP_FIELDS() >>>>> ) >>>>> >>>>> Note that I notice that some care will need to be taken to generate the >>>>> TP_FIELDS() from your existing trace-events file, an example: >>>>> >>>>> g_realloc(void *ptr, size_t size, void *newptr) >>>>> >>>>> would have to be translated to: >>>>> >>>>> TRACE_EVENT(qemu_kvm, g_realloc, >>>>> TP_ARGS(void *, ptr, size_t, size, void *, newptr), >>>>> TP_FIELDS( >>>>> ctf_integer_hex(void *, ptr, ptr) >>>>> ctf_integer(size_t, size, size) >>>>> ctf_integer_hex(void *, newptr, newptr) >>>>> ) >>>>> ) >>>>> >>>>> Note that the bright side is that the tracepoint probe does not need to >>>>> be hand-coded anymore, and there is no need to use the markers anymore >>>>> neither, which makes the tracer much faster. >>>>> >>>>> For most of your fields (using %p, %d style format strings), you should >>>>> use ctf_integer or ctf_integer_hex (the latter lets the trace viewer >>>>> know that the data should be printed as hexadecimal). >>>>> You will likely need to detect the %s format strings you have there and >>>>> translate them into ctf_string(field, field) too. You can have a >>>>> look at >>>>> lttng-ust tests/hello/*.[ch] for examples. >>>> >>>> Thanks for the info, I will look into it later. >>>>> >>>>> The call which would have looked like trace_qemu_kvm_g_realloc() in UST >>>>> 0.x should now be done with: >>>>> >>>>> tracepoint(qemu_kvm, g_realloc, ptr, size, newptr); >>>>> >>>>> This is needed to (very soon) add support for sdt.h in LTTng-UST >>>>> 2.0, so >>>>> systemtap and gdb can hook into tracepoints declared by lttng-ust 2.0. >>>>> >>>>> Best regards, >>>>> >>>>> Mathieu >>>>> >>>>>> >>>>>> regards, >>>>>> Harsh >>>>>> >>>>>>> Best regards, >>>>>>> >>>>>>> Mathieu >>>>>>> >>>>>>>> >>>>>>>> Version History: >>>>>>>> >>>>>>>> v2: >>>>>>>> - Updated tracetool.py to support nop, stderr, dtrace backend >>>>>>>> >>>>>>>> v1: >>>>>>>> - Working protoype with tracetool.py converted only for >>>>>>>> simpletrace backend >>>>>>>> >>>>>>>> Harsh Prateek Bora (4): >>>>>>>> Converting tracetool.sh to tracetool.py >>>>>>>> Makefile and configure changes for tracetool.py >>>>>>>> simpletrace-v2: Handle variable number/size of elements per trace >>>>>>>> record. >>>>>>>> simpletrace.py: updated log reader script to handle new log format >>>>>>>> >>>>>>>> Makefile.objs | 6 +- >>>>>>>> Makefile.target | 10 +- >>>>>>>> configure | 4 +- >>>>>>>> monitor.c | 2 +- >>>>>>>> scripts/simpletrace.py | 110 ++++++++++- >>>>>>>> scripts/tracetool.py | 505 >>>>>>>> ++++++++++++++++++++++++++++++++++++++++++++++++ >>>>>>>> trace/simple.c | 178 ++++++----------- >>>>>>>> trace/simple.h | 31 +++- >>>>>>>> 8 files changed, 702 insertions(+), 144 deletions(-) >>>>>>>> create mode 100755 scripts/tracetool.py >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>>> >>>> _______________________________________________ >>>> lttng-dev mailing list >>>> lttng-...@lists.lttng.org >>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev >>> >> > -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com
