Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On Sat, 16 Jul 2011 14:13:49 -0400, Michael Orlitzky wrote: CFLAGS=-march=native -O2 -pipe enables everything safe these days. As long as you don't want the VM to be portable. -- Neil Bothwick Angular Momentum Makes The World Go 'Round signature.asc Description: PGP signature
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On Sat, Jul 16, 2011 at 9:13 PM, Michael Orlitzky mich...@orlitzky.comwrote: On 07/16/2011 09:54 AM, Kfir Lavi wrote: Hi, I'm creating a router based on Gentoo, that needs to run as a vm using qemu. The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? Thanks, Kfir CFLAGS=-march=native -O2 -pipe enables everything safe these days. Hi, I think -march=native is a problem, as it will compile for my cpu. Qemu has different CPU, and i would like to compile my code to suit the vm environment as close as possible. Kfir
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
qemu has an option `*qemu* -*cpu host` that will use the host cpu features* 2011/7/17 Kfir Lavi lavi.k...@gmail.com On Sat, Jul 16, 2011 at 9:13 PM, Michael Orlitzky mich...@orlitzky.comwrote: On 07/16/2011 09:54 AM, Kfir Lavi wrote: Hi, I'm creating a router based on Gentoo, that needs to run as a vm using qemu. The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? Thanks, Kfir CFLAGS=-march=native -O2 -pipe enables everything safe these days. Hi, I think -march=native is a problem, as it will compile for my cpu. Qemu has different CPU, and i would like to compile my code to suit the vm environment as close as possible. Kfir
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On Saturday, July 16 at 16:54 (+0300), Kfir Lavi said: The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? A router is not going to be CPU-bound. Should matter little either way.
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On Sun, Jul 17, 2011 at 8:02 AM, Albert Hopkins mar...@letterboxes.org wrote: On Saturday, July 16 at 16:54 (+0300), Kfir Lavi said: The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? A router is not going to be CPU-bound. Should matter little either way. I agree it's not likely to matter significantly. In a VM environment, though, it could conceivably be routing traffic between other VM guests, and the nature of their locality could easily result in higher traffic flows than you'd ever see running across a wire. Depends on the use case, I imagine. -- :wq
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On 17 July 2011, at 13:02, Albert Hopkins wrote: On Saturday, July 16 at 16:54 (+0300), Kfir Lavi said: The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? A router is not going to be CPU-bound. Should matter little either way. A router is not going to be CPU-bound *on the most modern of hardware*, with no other load. An old WRT54G will be CPU-bound on the latest high speed home connections (c 40meg), and I have at least one older PC, maybe 10 years old, still in use, on which performance could be an issue. Your statement may apply to Kfir's Core I7 system, but it one should be careful against making such bold statements, less words like not be misunderstood be to mean never. Stroller.
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On Sat, Jul 16, 2011 at 10:54, Kfir Lavi lavi.k...@gmail.com wrote: Hi, I'm creating a router based on Gentoo, that needs to run as a vm using qemu. The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? If you intend to run this VM on different hardware or distribute it in any way (so you don't really know on what hardware it will run) your best bet is to set a generic arch like i686 or lower, OR hope the VM is run on software based emulation (slow) so you don't have to worry about what CPU is running it. From my experience with qemu, you'll have a lot of requirements too, like bridging and kernel module for virtual interfaces (tun/tap). Now, if this will run on your machine, with kqemu, you'll set march on your guest as your host is... -- Daniel da Veiga
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On Sun, Jul 17, 2011 at 7:19 PM, Daniel da Veiga danieldave...@gmail.comwrote: On Sat, Jul 16, 2011 at 10:54, Kfir Lavi lavi.k...@gmail.com wrote: Hi, I'm creating a router based on Gentoo, that needs to run as a vm using qemu. The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? If you intend to run this VM on different hardware or distribute it in any way (so you don't really know on what hardware it will run) your best bet is to set a generic arch like i686 or lower, OR hope the VM is run on software based emulation (slow) so you don't have to worry about what CPU is running it. From my experience with qemu, you'll have a lot of requirements too, like bridging and kernel module for virtual interfaces (tun/tap). Now, if this will run on your machine, with kqemu, you'll set march on your guest as your host is... -- Daniel da Veiga I'll build each router for its box. I don't want to use i686 as I'll run also on Atom, and this comp is really really slow with kvm support. Kfir
Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On 07/16/2011 09:54 AM, Kfir Lavi wrote: Hi, I'm creating a router based on Gentoo, that needs to run as a vm using qemu. The mother machine will be Core I7 4 cores. What cpu and CFLAGS should I use to get the best performance out of this vm? Thanks, Kfir CFLAGS=-march=native -O2 -pipe enables everything safe these days.
Re: [gentoo-user] Best CFLAGS
On Friday, 23 June 2006 9:04, Thiago Lüttig wrote: Hi folks, I have an Athlon XP 2600+ with 512MB of RAM and I was wondering about the best CFLAGS to make my executables run-like-hell :). Does anyone have a machine like this ?? I just can't stand windows XP anymore on my home box, but i want to put my future gentoo box run faster than a lightning(or something like that :] ) Thanx. The best cflags are those on the safe cflags list at: http://gentoo-wiki.com/Safe_Cflags If you use stupid cflags you will most probably encounter serious breakage and simply be told to revert to the safe cflags and emerge world before you receive much help. Packages that benefit greatly from certain cflags usually override your cflags with better ones in the ebuild. For example I believe xine-lib will force -O3 regardless of what you specify in make.conf. -- Raymond Lewis Rebbeck -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Best CFLAGS
2006/6/22, Thiago Lüttig [EMAIL PROTECTED]: Hi folks, I have an Athlon XP 2600+ with 512MB of RAM and I was wondering about the best CFLAGS to make my executables run-like-hell :).Does anyone have a machine like this ?? I just can't stand windows XP anymore on my home box, but i want to put my future gentoo box run faster than a lightning(or something like that :] ) Thanx. Best for what? -march=athlon-xp -mtune=athlon-xp -O2 -pipe is safe and give you a great performance i use thisCFLAGSfor a similar machine Athlon XP 2600 (core Barton)--aryix
Re: [gentoo-user] Best CFLAGS
ArYiX wrote: 2006/6/22, Thiago Lüttig [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: Hi folks, I have an Athlon XP 2600+ with 512MB of RAM and I was wondering about the best CFLAGS to make my executables run-like-hell :). Does anyone have a machine like this ?? I just can't stand windows XP anymore on my home box, but i want to put my future gentoo box run faster than a lightning(or something like that :] ) Thanx. Best for what? -march=athlon-xp -mtune=athlon-xp -O2 -pipe is safe and give you a great performance i use this CFLAGS for a similar machine Athlon XP 2600 (core Barton) --aryix I have been using this one for quite a while now and no problems yet anyway. CFLAGS=-march=athlon-xp -O2 -fomit-frame-pointer -momit-leaf-frame-pointer -fno-ident -pipe I got it from here: http://forums.gentoo.org/viewtopic-p-2314776.html#2314776 We have pretty similiar rigs. AMD 2500+ with 1GB of ram. Hope that helps Dale :-) :-) -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Best CFLAGS
On Friday 23 June 2006 02:20, ArYiX wrote: 2006/6/22, Thiago Lüttig [EMAIL PROTECTED]: Hi folks, I have an Athlon XP 2600+ with 512MB of RAM and I was wondering about the best CFLAGS to make my executables run-like-hell :). Does anyone have a machine like this ?? I just can't stand windows XP anymore on my home box, but i want to put my future gentoo box run faster than a lightning(or something like that :] ) Thanx. Best for what? -march=athlon-xp -mtune=athlon-xp -O2 -pipe is safe and give you a great performance tröööt. If you use march, mtune is superflous ;) -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Best CFLAGS
Hemmann, Volker Armin [EMAIL PROTECTED] writes: If you use march, mtune is superflous ;) Except for builds which override -march but do not touch -mtune. -- gentoo-user@gentoo.org mailing list
