On Mon, 27 May 2019 08:55:49 +0200
Laurent Vivier <lviv...@redhat.com> wrote:
> On 24/05/2019 22:14, Eduardo Habkost wrote:
> > On Fri, May 24, 2019 at 04:39:12PM +0200, Laurent Vivier wrote:
> >> On 24/05/2019 16:10, Igor Mammedov wrote:
> >>> On Fri, 24 May 2019 12:35:21 +0200
> >>> Laurent Vivier <lviv...@redhat.com> wrote:
> >>>
> >>>> On pseries, core-ids are strongly binded to a node-id by the command
> >>>> line option. If an user tries to add a CPU to the wrong node, he has
> >>>> an error but it is not really helpful:
> >>>>
> >>>> qemu-system-ppc64 ... -smp 1,maxcpus=64,cores=1,threads=1,sockets=1 \
> >>>> -numa node,nodeid=0 -numa node,nodeid=1 ...
> >>>>
> >>>> (qemu) device_add power9_v2.0-spapr-cpu-core,core-id=30,node-id=1
> >>>> Error: node-id=1 must match numa node specified with -numa option
> >>>>
> >>>> This patch improves this error message by giving to the user the good
> >>>> topology information (node-id, socket-id and thread-id if they are
> >>>> available) to use with the core-id he's providing:
> >>>>
> >>>> Error: node-id=1 must match numa node specified with -numa option
> >>>> 'node-id 0'
> >>>>
> >>>> Signed-off-by: Laurent Vivier <lviv...@redhat.com>
> >>>> ---
> >>>>
> >>>> Notes:
> >>>> v3: only add the topology to the existing message
> >>>> As suggested by Igor replace
> >>>> Error: core-id 30 can only be plugged into node-id 0
> >>>> by
> >>>> Error: node-id=1 must match numa node specified with -numa
> >>>> option 'node-id 0'
> >>>> v2: display full topology in the error message
> >>>>>>> numa.c | 25 ++++++++++++++++++++++++-
> >>>> 1 file changed, 24 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/numa.c b/numa.c
> >>>> index 3875e1efda3a..7882ec294be4 100644
> >>>> --- a/numa.c
> >>>> +++ b/numa.c
> >>>> @@ -458,6 +458,27 @@ void qmp_set_numa_node(NumaOptions *cmd, Error
> >>>> **errp)
> >>>> set_numa_options(MACHINE(qdev_get_machine()), cmd, errp);
> >>>> }
> >>>> +static char *cpu_topology_to_string(const CPUArchId *cpu)
> >>>> +{
> >>>> + GString *s = g_string_new(NULL);
> >>>> + if (cpu->props.has_socket_id) {
> >>>> + g_string_append_printf(s, "socket-id %"PRId64,
> >>>> cpu->props.socket_id);
> >>>> + }
> >>>> + if (cpu->props.has_node_id) {
> >>>> + if (s->len) {
> >>>> + g_string_append_printf(s, ", ");
> >>>> + }
> >>>> + g_string_append_printf(s, "node-id %"PRId64,
> >>>> cpu->props.node_id);
> >>>> + }
> >>>> + if (cpu->props.has_thread_id) {
> >>>> + if (s->len) {
> >>>> + g_string_append_printf(s, ", ");
> >>>> + }
> >>>> + g_string_append_printf(s, "thread-id %"PRId64,
> >>>> cpu->props.thread_id);
> >>>> + }
> >>>> + return g_string_free(s, false);
> >>>> +}
> >>>
> >>> turns out we already have such helper: cpu_slot_to_string()
> >>
> >> It doesn't display the node-id but the core-id. And node-id is what we need
> >> to know.
> >
> > I'm confused about what you are trying to do here.
> >
> > On v1, the message looked like:
> > Error: core-id 30 can only be plugged into node-id 0
> >
> > which is probably good for spapr.
> >
> >
> > Then I suggested you added the other cpu->props fields. e.g. on
> > PC the message would look like:
> > Error: socket-id 20, core-id 30, thread-id 40 can only be plugged into
> > node-id 0
> >
> >
> > But you sent a v2 patch that would print this on PC:
> > Error: core-id 30 can only be plugged into socket-id 20, node-id 0,
> > thread-id 40
> >
> > which doesn't make sense to me.
> >
> >
> > Then in a reply to v2, Igor suggested:
> >
> > error_setg(errp, "node-id=%d must match numa node specified "
> > "with -numa option '%s'", node_id, topology);
> >
> >
> > Igor suggest would address the problem above. I expected it to become:
> > node-id=0 must match numa node specified with -numa option core-id=30
> > and on PC:
> > node-id=0 must match numa node specified with -numa option
> > socket-id=20,core-id=30,thread-id=40
> >
> > Or maybe it could include the input node-id too:
> > node-id=0 must match numa node specified with -numa option
> > node-id=1,core-id=30
> > and on PC:
> > node-id=0 must match numa node specified with -numa option
> > node-id=1,socket-id=20,core-id=30,thread-id=40
> >
> > Both options would work.
> >
> >
> > But you implemented code that would print:
> > Error: node-id=0 must match numa node specified with -numa option
> > 'node-id 1'
> > and on PC it would print:
> > Error: node-id=0 must match numa node specified with -numa option
> > 'socket-id 20 node-id 1 thread-id=40'
> >
> > which doesn't make sense to me.
> >
> >
> > I was expecting something like:
> > Error: CPU slot core-id=30 is bound to node-id 0, but node-id 1 was
> > specified
> > and on PC:
> > Error: CPU slot socket-id=20,core-id=30,thread-id=40 is bound to node-id
> > 0, but node-id 1 was specified
> >
> >
>
> The idea is to provide the information to the user to help him to know
> where the cpu can be plugged when it cannot on the node-id he originally
> provided.
>
> So all the solutions you propose sounds good to me.
>
> I only need you and Igor agree on the same one.
We with Eduardo basically agree on contents/set of properties to print,
it is only different phrasing (Eduardo's suggestion is better than what we have
now).
But lets get to what problem you are going to fix/improve. SO I've went ahead
and tried
with following CLI:
qemu-system-x86_64 -smp 1,maxcpus=4 -numa node,cpus=0-1 -numa node,cpus=2-3
-monitor stdio -device
qemu64-x86_64-cpu,socket-id=1,core-id=0,thread-id=0,node-id=1
end it errored out with:
qemu-system-x86_64: -device
qemu64-x86_64-cpu,socket-id=1,core-id=0,thread-id=0,node-id=1: node-id=1 must
match numa node specified with -numa option
As you see we already have all user provide properties for cpu (including
invalid ones) reported,
what we are missing is suggestion for valid node-id. How about following error
message:
qemu-system-x86_64: -device
qemu64-x86_64-cpu,socket-id=1,core-id=0,thread-id=0,node-id=1: invalid node-id,
must be 0
>
> Thanks,
> Laurent
