Messages in this thread | | | Date | Wed, 20 Mar 2019 14:18:47 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 02/25] tracing: Improve "if" macro code generation |
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On Wed, 20 Mar 2019 10:26:17 -0700 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> - Steven has this crazy model of "more underscores are better". They > aren't. They don't help if things nest anyway, but what does help is > meaningful names. Both when things don't nest, and when looking at > generated asm files.
Note, at the time I had Ingo as a mentor ;-)
> include/linux/compiler.h | 35 ++++++++++++++++++----------------- > 1 file changed, 18 insertions(+), 17 deletions(-) > > diff --git a/include/linux/compiler.h b/include/linux/compiler.h > index 445348facea9..8aaf7cd026b0 100644 > --- a/include/linux/compiler.h > +++ b/include/linux/compiler.h > @@ -53,23 +53,24 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, > * "Define 'is'", Bill Clinton > * "Define 'if'", Steven Rostedt > */ > -#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) > -#define __trace_if(cond) \ > - if (__builtin_constant_p(!!(cond)) ? !!(cond) : \ > - ({ \ > - int ______r; \ > - static struct ftrace_branch_data \ > - __aligned(4) \ > - __section("_ftrace_branch") \ > - ______f = { \ > - .func = __func__, \ > - .file = __FILE__, \ > - .line = __LINE__, \ > - }; \ > - ______r = !!(cond); \ > - ______f.miss_hit[______r]++; \ > - ______r; \ > - })) > +#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) > + > +#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) > + > +#define __trace_if_value(cond) ({ \ > + static struct ftrace_branch_data \ > + __aligned(4) \ > + __section("_ftrace_branch") \ > + __if_trace = { \ > + .func = __func__, \ > + .file = __FILE__, \ > + .line = __LINE__, \ > + }; \ > + (cond) ? \ > + (__if_trace.miss_hit[1]++,1) : \ > + (__if_trace.miss_hit[0]++,0); \
Probably want to add a space between the comma and the numbers.
But other than that.
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
> +}) > + > #endif /* CONFIG_PROFILE_ALL_BRANCHES */ > > #else
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