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Re: [Qemu-devel] [PATCH v5 2/2] vl:c: make sure that sockets are calcula
From: |
Igor Mammedov |
Subject: |
Re: [Qemu-devel] [PATCH v5 2/2] vl:c: make sure that sockets are calculated correctly in '-smp X' case |
Date: |
Wed, 5 Sep 2018 11:42:29 +0200 |
On Tue, 4 Sep 2018 22:40:49 -0300
Eduardo Habkost <address@hidden> wrote:
> On Tue, Sep 04, 2018 at 05:18:48PM +0200, Andrew Jones wrote:
> > On Tue, Sep 04, 2018 at 03:22:36PM +0200, Igor Mammedov wrote:
> > > commit
> > > (5cdc9b76e3 vl.c: Remove dead assignment)
> > > removed sockets calculation when 'sockets' weren't provided on CLI
> > > since there wasn't any users for it back then. Exiting checks
> > > are neither reachable
> > > } else if (sockets * cores * threads < cpus) {
> > > or nor triggable
> > > if (sockets * cores * threads > max_cpus)
> > > so we weren't noticing wrong topology since then, since users
> > > recalculate sockets adhoc on their own.
> > >
> > > However with deprecation check it becomes noticable, for example
> > > -smp 2
> > > will start printing warning:
> > > "warning: Invalid CPU topology deprecated: sockets (1) * cores (1) *
> > > threads (1) != maxcpus (2)"
> > > calculating sockets if they weren't specified.
> > >
> > > Fix it by returning back sockets calculation if it's omited on CLI.
> > >
> > > Signed-off-by: Igor Mammedov <address@hidden>
> > > ---
> > > vl.c | 5 ++++-
> > > 1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/vl.c b/vl.c
> > > index 7fd700e..333d638 100644
> > > --- a/vl.c
> > > +++ b/vl.c
> > > @@ -1210,11 +1210,14 @@ static void smp_parse(QemuOpts *opts)
> > >
> > > /* compute missing values, prefer sockets over cores over
> > > threads */
> > > if (cpus == 0 || sockets == 0) {
> > > - sockets = sockets > 0 ? sockets : 1;
> > > cores = cores > 0 ? cores : 1;
> > > threads = threads > 0 ? threads : 1;
> > > if (cpus == 0) {
> > > + sockets = sockets > 0 ? sockets : 1;
> > > cpus = cores * threads * sockets;
> > > + } else {
> > > + max_cpus = qemu_opt_get_number(opts, "maxcpus", cpus);
> > > + sockets = !sockets ? max_cpus / (cores * threads) :
> > > sockets;
>
> Why the !sockets check here? If we have reached this statement
> we know that (cpus == 0 || sockets == 0) is true and
> (cpus == 0) is false, so sockets is guaranteed to be 0.
Indeed, thanks for spotting it
I'll fix it up and respin
>
> Sorry for not spotting this earlier.
>
> > > }
> > > } else if (cores == 0) {
> > > threads = threads > 0 ? threads : 1;
> > > --
> > > 2.7.4
> > >
> > >
> >
> > Reviewed-by: Andrew Jones <address@hidden>
>
- [Qemu-devel] [PATCH v5 0/2] deprecate incorrect CPUs topology, Igor Mammedov, 2018/09/04
- [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Igor Mammedov, 2018/09/04
- Re: [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Andrew Jones, 2018/09/04
- [Qemu-devel] [PATCH v6 1/2] vl.c deprecate incorrect CPUs topology, Igor Mammedov, 2018/09/04
- Re: [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Eduardo Habkost, 2018/09/04
- Re: [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Igor Mammedov, 2018/09/05
- Re: [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Eduardo Habkost, 2018/09/05
- Re: [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Igor Mammedov, 2018/09/06
- Re: [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Eduardo Habkost, 2018/09/10
- Re: [Qemu-devel] [libvirt] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Eric Blake, 2018/09/10
- Re: [Qemu-devel] [PATCH v5 1/2] vl.c deprecate incorrect CPUs topology, Igor Mammedov, 2018/09/12