FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Gentoo > Gentoo User

 
 
LinkBack Thread Tools
 
Old 05-01-2008, 04:40 PM
James
 
Default -fomit-frame-pointer switch

Hello,

On an amd64, If I want to add -fomit-frame-pointer to a system's
CFLAGS setting, I can just add it and eventually all of the
executables will be recompile (willing to wait)
or do I have to rebuild system (all packages) or such to switch?


James

--
gentoo-user@lists.gentoo.org mailing list
 
Old 05-01-2008, 04:57 PM
Wolf Canis
 
Default -fomit-frame-pointer switch

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

James wrote:
| Hello,
|
| On an amd64, If I want to add -fomit-frame-pointer to a system's
| CFLAGS setting, I can just add it and eventually all of the
| executables will be recompile (willing to wait)
| or do I have to rebuild system (all packages) or such to switch?

Hello James,
you have to rebuild the entire system, if the new CFLAGS settings shall
have effect.

# emerge --emptytree system && emerge --emptytree world

That's the recommend procedure, according to the handbook, to do that.
But there are in the forums a big thread whether that is necessary or not.
Some argue - is not, it's sufficient to rebuild the toolchain and than
emerge -e world. Others say one should follow the recommend procedure.
I follow the recommend procedure.

Hope that helps.

W. Canis

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkgZ9lwACgkQKT9zBKF0twU8hgCgmSyN7hTtp+ FWizv/yVZXaTyL
2u8An0QMe2QaJUsxymGNTPo8QuDN+MUy
=BHyv
-----END PGP SIGNATURE-----

--
gentoo-user@lists.gentoo.org mailing list
 
Old 05-01-2008, 05:21 PM
James
 
Default -fomit-frame-pointer switch

Wolf Canis <wolf.canis <at> googlemail.com> writes:

>
>
> James wrote:
> | Hello,
> |
> | On an amd64, If I want to add -fomit-frame-pointer to a system's
> | CFLAGS setting, I can just add it and eventually all of the
> | executables will be recompile (willing to wait)
> | or do I have to rebuild system (all packages) or such to switch?
>
> Hello James,
> you have to rebuild the entire system, if the new CFLAGS settings shall
> have effect.
>

OK, I agree with that. BUT, if I do not then I do not get the benefits
of that compiler option, but wont the system still work fine? After a
while, over time, everything get's rebuilt anyway; If can wait a few months
for everything to slowly be recompiled. I'm not asking if this is wise,
recommended or will result immediately with binaries that are a result
of using "-fomit-frame-pointer".

I just want to know if the system will continue to function, albeit slower
that if I recompile the system and then world (using the syntax
you list below)?

> # emerge --emptytree system && emerge --emptytree world
>
> That's the recommend procedure, according to the handbook, to do that.
> But there are in the forums a big thread whether that is necessary or not.
> Some argue - is not, it's sufficient to rebuild the toolchain and than
> emerge -e world. Others say one should follow the recommend procedure.
> I follow the recommend procedure.


I do appreciate your answer, and agree with it from what I've read.

But in order to avoid recompiling all of those packages (for now)
I can just add it to my CFlags and wait a few months, as another option?

Or is there real peril with this approach to slowly converting a system?


James





--
gentoo-user@lists.gentoo.org mailing list
 
Old 05-01-2008, 05:23 PM
Uwe Thiem
 
Default -fomit-frame-pointer switch

On Thursday 01 May 2008, James wrote:
> Hello,
>
> On an amd64, If I want to add -fomit-frame-pointer to a system's
> CFLAGS setting, I can just add it and eventually all of the
> executables will be recompile (willing to wait)
> or do I have to rebuild system (all packages) or such to switch?

No need to rebuild the whole system. One-by-one is fine. A lot of
packages set it anyway.

Uwe

--
Ignorance killed the cat, sir, curiosity was framed!
--
gentoo-user@lists.gentoo.org mailing list
 
Old 05-01-2008, 05:28 PM
Justin
 
Default -fomit-frame-pointer switch

James schrieb:

Hello,

On an amd64, If I want to add -fomit-frame-pointer to a system's
CFLAGS setting, I can just add it and eventually all of the
executables will be recompile (willing to wait)
or do I have to rebuild system (all packages) or such to switch?


James



As the wiki says

SNIP

-fomit-frame-pointer tells gcc to omit frame pointers, freeing up an
additional register on the CPU. This is mainly useful on x86 as most
other arches, like AMD64, have it on by default at -O2 or greater


SNAP

you do not recompile anything, if you had -O2 or greater before.
 
Old 05-01-2008, 05:52 PM
Wolf Canis
 
Default -fomit-frame-pointer switch

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

James wrote:
|
| But in order to avoid recompiling all of those packages (for now)
| I can just add it to my CFlags and wait a few months, as another option?
Yes, there shouldn't any problems appear.
|
| Or is there real peril with this approach to slowly converting a system?
I think no. But I'm not that Guru, I'm not sure whether there is package
or dependency

which if new compiled failed or lead to any instability.

If you need that system for something important, I wouldn't recommend to
experiment
with CFLAGS. I would do that in a time window where I would have a
couple of days time.


That's what I would do. Because you can never know for sure whether it comes
to problems or not. ;-)

W. Canis

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkgaAz0ACgkQKT9zBKF0twXFHACfTBNKv0j9s6 Bo3cPmChf72X4x
+5sAmwcqUWggUQhC98o1duN0r/ylXsBH
=93sI
-----END PGP SIGNATURE-----

--
gentoo-user@lists.gentoo.org mailing list
 
Old 05-01-2008, 06:04 PM
James
 
Default -fomit-frame-pointer switch

Justin <justin <at> j-schmitz.net> writes:


> As the wiki says

I cannot seem to find this reference in any of the wikis
I use for Gentoo, perhaps a url so I can read more?


> -fomit-frame-pointer tells gcc to omit frame pointers, freeing up an
> additional register on the CPU. This is mainly useful on x86 as most
> other arches, like AMD64, have it on by default at -O2 or greater


> you do not recompile anything, if you had -O2 or greater before.


WONDERFUL answer.


Thanks to all that responded.


James





--
gentoo-user@lists.gentoo.org mailing list
 
Old 05-01-2008, 06:15 PM
Justin
 
Default -fomit-frame-pointer switch

James schrieb:

Justin <justin <at> j-schmitz.net> writes:




As the wiki says



I cannot seem to find this reference in any of the wikis
I use for Gentoo, perhaps a url so I can read more?




http://gentoo-wiki.com/CFLAGS#-fomit-frame-pointer
 

Thread Tools




All times are GMT. The time now is 03:25 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org