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    SubjectRe: RAS trace event proto
    On Mon, 2012-02-20 at 15:59 +0100, Borislav Petkov wrote:

    > * I'd like to have conditional printk-ing in trace_mce_record depending
    > on the TP args, Steve probably knows what can be done:

    /me is confused :-)

    > @Steven:
    > I'd like to do the following:
    > TP_printk("%s, ARG1: %d, ARG2: %c ...", str1, arg1, arg2)
    > and have it print only the first arg, i.e. the string and drop the rest
    > of the args while still doing the TP_fast_assign into the ring buffer
    > and carrying the stuff to its consumers. Background is that I want to
    > dump the decoded string of a hardware error, if it is decoded, but carry
    > the MCE info to userspace and only dump the fields of the MCE if I
    > haven't managed to decode it, i.e. str1 == "".
    > So, my question is, can I do something like:
    > TP_printk("%s, ARG1: %d, ARG2: %c ...", __print_conditional(str1, arg1, arg2))

    You want to affect the output of ftrace?

    perf and even trace-cmd do the parsing later and can be overridden.
    Well, perf can be when we finally get it to use the updated trace-cmd

    -- Steve

    > where __print_conditional is a vararg macro which calls a
    > ftrace_print_cond() which prints only str1 if strlen(str1) > 0 and
    > otherwise calls a vsnprintf() variant to deal with the va_args?

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      Last update: 2012-02-21 02:17    [W:0.039 / U:41.412 seconds]
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