Messages in this thread | | | From | jim.cromie@gmail ... | Date | Thu, 14 Dec 2023 00:09:56 -0700 | Subject | Re: [PATCH v2 09/15] dyndbg: add trace destination field to _ddebug |
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On Thu, Nov 30, 2023 at 4:41 PM Łukasz Bartosik <lb@semihalf.com> wrote: > > Add trace destination field (trace_dst) to the _ddebug structure. > The trace destination field is used to determine output of debug > logs when +T is set. Setting trace_dst value to TRACE_DST_BITS(63) > enables output to prdbg and devdbg trace events. Setting trace_dst > value to a value in range of [0..62] enables output to trace instance. >
FWIW, I think setting trace_dest = 0 maps naturally to global / event buf. The reason class_id DFLT is 63 is that DRM_UT_CORE is 0, and DFLT allowed it to remain unchanged.
> Signed-off-by: Łukasz Bartosik <lb@semihalf.com> > --- > include/linux/dynamic_debug.h | 14 ++++++++++++-- > lib/dynamic_debug.c | 28 +++++++++++++++++++--------- > 2 files changed, 31 insertions(+), 11 deletions(-) > > diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h > index 684766289bfc..56f152e75604 100644 > --- a/include/linux/dynamic_debug.h > +++ b/include/linux/dynamic_debug.h > @@ -60,9 +60,19 @@ struct _ddebug { > #else > #define _DPRINTK_FLAGS_DEFAULT 0 > #endif > - struct { > + struct dd_ctrl { > unsigned int flags:8; > - unsigned unused:24; > + /* > + * The trace destination field is used to determine output of debug > + * logs when +T is set. Setting trace_dst value to TRACE_DST_MAX(63) > + * enables output to prdbg and devdbg trace events. Setting trace_dst > + * value to a value in range of [0..62] enables output to trace > + * instance. > + */ > +#define TRACE_DST_BITS 6 > + unsigned int trace_dst:TRACE_DST_BITS; > +#define TRACE_DST_MAX ((1 << TRACE_DST_BITS) - 1) > + unsigned unused:18; > } ctrl; > } __attribute__((aligned(8))); > > diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c > index f47cb76e0e3d..0dc9ec76b867 100644 > --- a/lib/dynamic_debug.c > +++ b/lib/dynamic_debug.c > @@ -80,14 +80,24 @@ module_param(verbose, int, 0644); > MODULE_PARM_DESC(verbose, " dynamic_debug/control processing " > "( 0 = off (default), 1 = module add/rm, 2 = >control summary, 3 = parsing, 4 = per-site changes)"); > > +static inline struct dd_ctrl *get_ctrl(struct _ddebug *desc) > +{ > + return &desc->ctrl; > +} > + > +static inline void set_ctrl(struct _ddebug *desc, struct dd_ctrl *ctrl) > +{ > + desc->ctrl = *ctrl; > +} > + > static inline unsigned int get_flags(const struct _ddebug *desc) > { > return desc->ctrl.flags; > } > > -static inline void set_flags(struct _ddebug *desc, unsigned int val) > +static inline unsigned int get_trace_dst(const struct _ddebug *desc) > { > - desc->ctrl.flags = val; > + return desc->ctrl.trace_dst; > } > > /* Return the path relative to source root */ > @@ -190,8 +200,8 @@ static int ddebug_change(const struct ddebug_query *query, > { > int i; > struct ddebug_table *dt; > - unsigned int newflags; > unsigned int nfound = 0; > + struct dd_ctrl nctrl = {0}; > struct flagsbuf fbuf, nbuf; > struct ddebug_class_map *map = NULL; > int __outvar valid_class; > @@ -257,14 +267,14 @@ static int ddebug_change(const struct ddebug_query *query, > > nfound++; > > - newflags = (get_flags(dp) & modifiers->mask) | modifiers->flags; > - if (newflags == get_flags(dp)) > + nctrl.flags = (get_flags(dp) & modifiers->mask) | modifiers->flags; > + if (!memcmp(&nctrl, get_ctrl(dp), sizeof(struct dd_ctrl))) > continue; > #ifdef CONFIG_JUMP_LABEL > if (get_flags(dp) & _DPRINTK_FLAGS_ENABLED) { > - if (!(newflags & _DPRINTK_FLAGS_ENABLED)) > + if (!(nctrl.flags & _DPRINTK_FLAGS_ENABLED)) > static_branch_disable(&dp->key.dd_key_true); > - } else if (newflags & _DPRINTK_FLAGS_ENABLED) { > + } else if (nctrl.flags & _DPRINTK_FLAGS_ENABLED) { > static_branch_enable(&dp->key.dd_key_true); > } > #endif > @@ -272,8 +282,8 @@ static int ddebug_change(const struct ddebug_query *query, > trim_prefix(dp->filename), dp->lineno, > dt->mod_name, dp->function, > ddebug_describe_flags(get_flags(dp), &fbuf), > - ddebug_describe_flags(newflags, &nbuf)); > - set_flags(dp, newflags); > + ddebug_describe_flags(nctrl.flags, &nbuf)); > + set_ctrl(dp, &nctrl); > } > } > mutex_unlock(&ddebug_lock); > -- > 2.43.0.rc2.451.g8631bc7472-goog >
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