From: anupam.kapoor@gmail.com (Anupam Kapoor)
To: kernelnewbies@lists.kernelnewbies.org
Subject: unlikely compiler flag propagation
Date: Thu, 19 Feb 2015 17:04:07 +0530 [thread overview]
Message-ID: <87lhjuxhhs.fsf@fatcat.parallelwireless> (raw)
In-Reply-To: <20150218183801.GA1773@opentech.at>
>>>>> [2015-02-19T00:08:01+0530]: "Nicholas Mc Guire" (nicholas-mcguire):
nicholas-mcguire> On Wed, 18 Feb 2015, Greg KH wrote:
,----[ greg-kh ]
| As proof of this, there was a test of the kernel a year or so ago that
| measured the placement of the existing likely/unlikely markers in the
| kernel and 90% of the usages were wrong and actually slowed down the
| processor.
`----
,----[ nicholas-mcguire ]
| interesting - would you have a reference to some talk/paper/data/... ?
`----
couple of 'slightly' oldish posts:
http://blog.man7.org/2012/10/how-much-do-builtinexpect-likely-and.html and
http://thread.gmane.org/gmane.linux.kernel/1072767
---
thanks
anupam
prev parent reply other threads:[~2015-02-19 11:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-18 18:09 unlikely compiler flag propagation Matthias Brugger
2015-02-18 18:24 ` Greg KH
2015-02-18 18:35 ` Matthias Brugger
2015-02-18 19:02 ` Greg KH
2015-02-18 18:38 ` Nicholas Mc Guire
2015-02-18 18:57 ` Valdis.Kletnieks at vt.edu
2015-02-18 19:02 ` Nicholas Mc Guire
2015-02-19 11:34 ` Anupam Kapoor [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87lhjuxhhs.fsf@fatcat.parallelwireless \
--to=anupam.kapoor@gmail.com \
--cc=kernelnewbies@lists.kernelnewbies.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).