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    SubjectRe: [PATCH 07/15] mm: Add ___GFP_NOTRACE
    On Mon, 2 Mar 2015 10:12:32 -0800
    Alexei Starovoitov <ast@plumgrid.com> wrote:

    > I'm not sure what would be the meaning of hash map that has all
    > elements pre-allocated...
    > As I'm reading your cover letter, I agree, we need to find a way
    > to call kmalloc_notrace-like from tracepoints.
    > Not sure that patch 8 style of duplicating the functions is clean.
    > Can we keep kmalloc/kfree as-is and do something like
    > if (in_tracepoint()) check inside ftrace_raw_kmalloc* ?

    I'm strongly against this. You should not be doing anything in a
    tracepoint that you can't do from NMI context. And calling kmalloc
    happens to be one of them.

    Not to mention, kmalloc is a hot path, and tracing must not have any
    impact on it (no extra if statements).

    -- Steve

    > so that kmalloc will be traced but calls to kmalloc from inside
    > tracepoints will be automatically suppressed ?



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