Re: [gentoo-user] best cflags and cpu for gentoo qemu virtual machine
On Sun, Jul 17, 2011 at 7:19 PM, Daniel da Veiga wrote: > On Sat, Jul 16, 2011 at 10:54, 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? >> >> > 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 Sat, Jul 16, 2011 at 10:54, 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? > > 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 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 Sun, Jul 17, 2011 at 8:02 AM, 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. 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 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
qemu has an option `*qemu* -*cpu host` that will use the host cpu features* 2011/7/17 Kfir Lavi > > > On Sat, Jul 16, 2011 at 9:13 PM, Michael Orlitzky wrote: > >> 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 Sat, Jul 16, 2011 at 9:13 PM, Michael Orlitzky wrote: > 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 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 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.
[gentoo-user] best cflags and cpu for gentoo qemu virtual machine
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
