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From: Phil Blundell <pb@pbcl.net>
To: Khem Raj <raj.khem@gmail.com>
Cc: Patches and discussions about the oe-core layer
	<openembedded-core@lists.openembedded.org>
Subject: Re: Default value for FULL_OPTIMIZATION
Date: Wed, 03 Feb 2016 21:08:28 +0000	[thread overview]
Message-ID: <1454533708.7421.61.camel@pbcl.net> (raw)
In-Reply-To: <CAMKF1srGn-maJcvPLQSV6Xz7RgU4N1Jipr+Oc9AH_B1xsj-UQw@mail.gmail.com>

On Wed, 2016-02-03 at 12:59 -0800, Khem Raj wrote:
> in systems of  this age it should be yet.

Sorry, I didn't really understand that comment.

For what it's worth, as a very quick and fairly unscientific comparison,
I did "time make -j4" in a glibc tree and got:

real	1m38.812s
user	4m6.420s
sys	0m23.148s

and then I cleaned the tree and did "time make -j4 CFLAGS='-O2 -g
-pipe'" and got:

real	1m37.299s
user	4m21.420s
sys	0m27.304s

I'm not sure these results are statistically significant but on this
very limited evidence it certainly doesn't look like -pipe is providing
any transformational benefits.  The real time has gone down a tiny bit,
which suggests that -pipe is giving some extra parallelism, but the
system and user time have both actually gone up in the second case. 

p.




  reply	other threads:[~2016-02-03 21:08 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-02 13:26 Default value for FULL_OPTIMIZATION Pascal Bach
2016-02-02 14:26 ` Mike Looijmans
2016-02-02 16:23   ` Pascal Bach
2016-02-02 14:47 ` Richard Purdie
2016-02-02 20:52 ` Phil Blundell
2016-02-03  6:17   ` Khem Raj
2016-02-03 20:48     ` Phil Blundell
2016-02-03 20:51       ` Khem Raj
2016-02-03 20:54         ` Burton, Ross
2016-02-03 20:57         ` Phil Blundell
2016-02-03 20:59           ` Khem Raj
2016-02-03 21:08             ` Phil Blundell [this message]
2016-02-03 22:37               ` Khem Raj
2016-02-04 12:56             ` Mike Looijmans

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