[lkml]   [2009]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] WARN_ONCE(): use bool for boolean flag
On Sun, 2009-09-27 at 14:24 -0300, Cesar Eduardo Barros wrote:

> I took a quick look, and all uses seem to be directly in a boolean
> context (within an if()), so there would be no problem. Besides, the
> unlikely() all these macros end with does a double negation, meaning
> even if it is an int, it will be either 0 or 1 (but I am not sure I am
> reading these macros right - it seems CONFIG_TRACE_BRANCH_PROFILING
> turns all unlikely() into likely()).
> In fact, I was expecting no change at all, since gcc should be able to
> see it is being treated as a boolean (perhaps I am trusting gcc too
> much). And to make matters even more confusing, my own test changing all
> __ret_warn_once to bool and dropping the !! caused an _increase_ of 598
> bytes (x86-64 defconfig).
> text data bss dec hex filename
> 8100553 1207148 991988 10299689 9d2929 vmlinux.warnret.before
> 8101119 1207180 991988 10300287 9d2b7f vmlinux.warnret.after
> (And yes, data increased again.)

Did you have the CONFIG_TRACE_BRANCH_PROFILING option enabled for the
test above?

If this was just your regular base line config , then that is odd .. I
also would think worse case would be no size reduction .. I did my
compile test on x86-32 btw..



 \ /
  Last update: 2009-09-27 19:35    [W:0.044 / U:1.964 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site