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Re: [Qemu-devel] [PATCH qemu] sysemu: support up to 1024 vCPUs
From: |
Igor Mammedov |
Subject: |
Re: [Qemu-devel] [PATCH qemu] sysemu: support up to 1024 vCPUs |
Date: |
Wed, 19 Oct 2016 14:23:40 +0200 |
On Wed, 19 Oct 2016 10:39:12 +1100
Alexey Kardashevskiy <address@hidden> wrote:
> On 18/10/16 22:00, Igor Mammedov wrote:
> > On Tue, 11 Oct 2016 09:19:10 +1100
> > Alexey Kardashevskiy <address@hidden> wrote:
> >
> >> Ping, anyone?
> > I have a similar patch
> > http://patchwork.ozlabs.org/patch/681709/
> > which bumps limit to 288 and does a little bit more
> > so it wouldn't affect current users.
>
> Why 288 (not oldlimit<<n)? :)
That's how many vCPU we plan to support for target-i386.
> What does happen to the Greg's patch now?
it could be amended to apply top of above patch,
where it would change not only MAX_CPUMASK_BITS but also
maxcpus in ppc target since above patch unties maxcpus
from MAX_CPUMASK_BITS for all targets.
So followup increases of MAX_CPUMASK_BITS won't affect
other targets.
>
>
> >
> > After that's merged, I plan to get rid of this limit and
> > make that part of numa parsing code dynamic so that it
> > wouldn't impose such limit/any limits on target code.
> >
> >>
> >>
> >> On 04/10/16 11:33, Alexey Kardashevskiy wrote:
> >>> From: Greg Kurz <address@hidden>
> >>>
> >>> Some systems can already provide more than 255 hardware threads.
> >>>
> >>> Bumping the QEMU limit to 1024 seems reasonable:
> >>> - it has no visible overhead in top;
> >>> - the limit itself has no effect on hot paths.
> >>>
> >>> Signed-off-by: Greg Kurz <address@hidden>
> >>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> >>> ---
> >>> include/sysemu/sysemu.h | 2 +-
> >>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> >>> index ef2c50b..2ec0bd8 100644
> >>> --- a/include/sysemu/sysemu.h
> >>> +++ b/include/sysemu/sysemu.h
> >>> @@ -173,7 +173,7 @@ extern int mem_prealloc;
> >>> *
> >>> * Note that cpu->get_arch_id() may be larger than MAX_CPUMASK_BITS.
> >>> */
> >>> -#define MAX_CPUMASK_BITS 255
> >>> +#define MAX_CPUMASK_BITS 1024
> >>>
> >>> #define MAX_OPTION_ROMS 16
> >>> typedef struct QEMUOptionRom {
> >>>
> >>
> >>
> >
>
>