Re: [Qemu-devel] [PATCH] xen: Avoid useless allocation in Xen case.

2011-08-02 Thread Jan Kiszka
On 2011-08-02 14:13, Anthony PERARD wrote: > On Tue, Aug 2, 2011 at 11:49, Jan Kiszka wrote: >>> The same applies to kvm, please generalize. >> >> Actually, qemu-kvm avoids this overhead today by making code_gen_alloc >> return immediately when kvm is on. Also not very beautiful. >> >> Can't we si

Re: [Qemu-devel] [PATCH] xen: Avoid useless allocation in Xen case.

2011-08-02 Thread Anthony PERARD
On Tue, Aug 2, 2011 at 11:49, Jan Kiszka wrote: >> The same applies to kvm, please generalize. > > Actually, qemu-kvm avoids this overhead today by making code_gen_alloc > return immediately when kvm is on. Also not very beautiful. > > Can't we simply skip cpu_exec_init_all for any accel != TCG, e

Re: [Qemu-devel] [PATCH] xen: Avoid useless allocation in Xen case.

2011-08-02 Thread Jan Kiszka
On 2011-08-01 21:57, Jan Kiszka wrote: > On 2011-08-01 21:26, Anthony PERARD wrote: >> The code_gen_buffer is not use by Xen and can be really big (several >> GB). Even if the host RAM is not used, this buffer just burn the address >> space of the QEMU process. >> >> So to "avoid" this allocation,

Re: [Qemu-devel] [PATCH] xen: Avoid useless allocation in Xen case.

2011-08-01 Thread Jan Kiszka
On 2011-08-01 21:26, Anthony PERARD wrote: > The code_gen_buffer is not use by Xen and can be really big (several > GB). Even if the host RAM is not used, this buffer just burn the address > space of the QEMU process. > > So to "avoid" this allocation, the asked tb_size is set to the minimum. > >