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    SubjectRe: [PATCH v1 07/12] dyndbg: repack struct _ddebug
    On Fri, Nov 3, 2023 at 7:10 AM Łukasz Bartosik <lb@semihalf.com> wrote:
    >
    > From: Jim Cromie <jim.cromie@gmail.com>
    >
    > Move the JUMP_LABEL to the top of the struct, since theyre both
    > align(8) and this closes a pahole (unfortunately trading for padding,
    > but still).
    >
    > Signed-off-by: Jim Cromie <jim.cromie@gmail.com>

    let me add, I havent really tested this, nevermind thorough.
    specifically, I didnt look for any offset dependence on the static-key
    inside their container.
    Conversely, maybe theres a free default or something in there.

    > ---
    > include/linux/dynamic_debug.h | 12 ++++++------
    > 1 file changed, 6 insertions(+), 6 deletions(-)
    >
    > diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
    > index 497130816e9c..b9237e4ecd1b 100644
    > --- a/include/linux/dynamic_debug.h
    > +++ b/include/linux/dynamic_debug.h
    > @@ -14,6 +14,12 @@
    > * the special section is treated as an array of these.
    > */
    > struct _ddebug {
    > +#ifdef CONFIG_JUMP_LABEL
    > + union {
    > + struct static_key_true dd_key_true;
    > + struct static_key_false dd_key_false;
    > + } key;
    > +#endif
    > /*
    > * These fields are used to drive the user interface
    > * for selecting and displaying debug callsites.
    > @@ -53,12 +59,6 @@ struct _ddebug {
    > #define _DPRINTK_FLAGS_DEFAULT 0
    > #endif
    > unsigned int flags:8;
    > -#ifdef CONFIG_JUMP_LABEL
    > - union {
    > - struct static_key_true dd_key_true;
    > - struct static_key_false dd_key_false;
    > - } key;
    > -#endif
    > } __attribute__((aligned(8)));
    >
    > enum class_map_type {
    > --
    > 2.42.0.869.gea05f2083d-goog
    >

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