[lkml]   [2017]   [Oct]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v7] printk: hash addresses printed with %p
On Thu, Oct 26, 2017 at 09:00:03AM +0200, Greg KH wrote:
> On Thu, Oct 26, 2017 at 12:59:08AM +0200, Jason A. Donenfeld wrote:
> > On Thu, Oct 26, 2017 at 12:27 AM, Tobin C. Harding <> wrote:
> > > How good is unlikely()?
> >
> > It places that branch way at the bottom of the function so that it's
> > less likely to pollute the icache.
> But always measure it. Lots of times (old numbers were 90% or so), we
> get the marking wrong, so please, always benchmark the thing to verify
> it actually is doing what you think it should be doing, otherwise it
> could make the code worse.

Does this come under 'premature optimization is the root of all evil'?

Should we be leaving out things like unlikely() and __read_only until
the code has been profiled?


 \ /
  Last update: 2017-10-26 11:11    [W:0.065 / U:1.692 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site