lkml.org 
[lkml]   [2005]   [Aug]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch] IBM HDAPS accelerometer driver, with probing.
Andi Kleen wrote:
> - it doesn't seem to help that much on modern CPUs with good
> branch prediction and big icaches anyways.

Really? I would think that as pipelines get deeper (although that trend
seems to have stopped, thankfully) and Icache-miss penalties get relatively
larger we'd see unlikely() becoming MORE of a benefit, not less. Storing
the used part of a "hot" function in 1 Icacheline instead of 4 seems like
an obvious win.

Personally I've never found unlikely() to be ugly; if anything I think
it serves as a nice little human-readable comment about whats going on
in the control-flow. I guess I'm in the minority on that one, though.

-Mitch
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-08-27 06:01    [W:0.083 / U:1.376 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site