| Message ID | 111bea6806c8d7e0f20856e75edba74f86a6bc9b.1365430186.git.minovotn@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 04/08/2013 10:41 AM, Michal Novotny wrote: > Alter the query-machines QMP command to output information about > maximum number of CPUs for each machine type with default value > set to 1 in case the number of max_cpus is not set. > > Signed-off-by: Michal Novotny <minovotn@redhat.com> > --- > qapi-schema.json | 4 +++- > vl.c | 1 + > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/qapi-schema.json b/qapi-schema.json > index db542f6..689ca8d 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -2861,11 +2861,13 @@ > # > # @default: #optional whether the machine is default > # > +# @cpu-max: maximum number of CPUs supported by the machine type Typically, when adding a field in a later version than the original introduction of the datatype, we add '(since 1.5)' to make it obvious when to expect the field. However, as nothing (currently) enforces this rule, I think such an addition is minor enough that it wouldn't invalidate the use of my: Reviewed-by: Eric Blake <eblake@redhat.com>
On Mon, 08 Apr 2013 11:14:32 -0600 Eric Blake <eblake@redhat.com> wrote: > On 04/08/2013 10:41 AM, Michal Novotny wrote: > > Alter the query-machines QMP command to output information about > > maximum number of CPUs for each machine type with default value > > set to 1 in case the number of max_cpus is not set. > > > > Signed-off-by: Michal Novotny <minovotn@redhat.com> > > --- > > qapi-schema.json | 4 +++- > > vl.c | 1 + > > 2 files changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/qapi-schema.json b/qapi-schema.json > > index db542f6..689ca8d 100644 > > --- a/qapi-schema.json > > +++ b/qapi-schema.json > > @@ -2861,11 +2861,13 @@ > > # > > # @default: #optional whether the machine is default > > # > > +# @cpu-max: maximum number of CPUs supported by the machine type > > Typically, when adding a field in a later version than the original > introduction of the datatype, we add '(since 1.5)' to make it obvious > when to expect the field. However, as nothing (currently) enforces this > rule, I think such an addition is minor enough that it wouldn't > invalidate the use of my: Oh, it turns out I was making some confusion with this patch and didn't realize it was extending the query-machines command. I don't mean there's anything wrong with it, but my question is: doesn't this patch invalidates query-cpu-max? PS: I can add the '(since 1.5)' line myself. > > Reviewed-by: Eric Blake <eblake@redhat.com> >
On 04/09/2013 03:06 PM, Luiz Capitulino wrote: > On Mon, 08 Apr 2013 11:14:32 -0600 > Eric Blake <eblake@redhat.com> wrote: > >> On 04/08/2013 10:41 AM, Michal Novotny wrote: >>> Alter the query-machines QMP command to output information about >>> maximum number of CPUs for each machine type with default value >>> set to 1 in case the number of max_cpus is not set. >>> >>> Signed-off-by: Michal Novotny <minovotn@redhat.com> >>> --- >>> qapi-schema.json | 4 +++- >>> vl.c | 1 + >>> 2 files changed, 4 insertions(+), 1 deletion(-) >>> >>> diff --git a/qapi-schema.json b/qapi-schema.json >>> index db542f6..689ca8d 100644 >>> --- a/qapi-schema.json >>> +++ b/qapi-schema.json >>> @@ -2861,11 +2861,13 @@ >>> # >>> # @default: #optional whether the machine is default >>> # >>> +# @cpu-max: maximum number of CPUs supported by the machine type >> Typically, when adding a field in a later version than the original >> introduction of the datatype, we add '(since 1.5)' to make it obvious >> when to expect the field. However, as nothing (currently) enforces this >> rule, I think such an addition is minor enough that it wouldn't >> invalidate the use of my: > Oh, it turns out I was making some confusion with this patch and > didn't realize it was extending the query-machines command. > > I don't mean there's anything wrong with it, but my question is: doesn't > this patch invalidates query-cpu-max? Not really, the query-cpu-max shows maximum number of CPUs supported per currently running machine (machine type) however the extension to query-machines shows the maximum number of CPUs supported per each of the displayed machine types. This usually doesn't matter on x86 architectures however it does matter on ARM, for example, as ARM has some CPU models supporting up to 4 CPUs (highbank model) whereas most of the ARM processors does have only one CPU. Michal > > PS: I can add the '(since 1.5)' line myself. > >> Reviewed-by: Eric Blake <eblake@redhat.com> >>
On Tue, 09 Apr 2013 15:09:21 +0200 Michal Novotny <minovotn@redhat.com> wrote: > > On 04/09/2013 03:06 PM, Luiz Capitulino wrote: > > On Mon, 08 Apr 2013 11:14:32 -0600 > > Eric Blake <eblake@redhat.com> wrote: > > > >> On 04/08/2013 10:41 AM, Michal Novotny wrote: > >>> Alter the query-machines QMP command to output information about > >>> maximum number of CPUs for each machine type with default value > >>> set to 1 in case the number of max_cpus is not set. > >>> > >>> Signed-off-by: Michal Novotny <minovotn@redhat.com> > >>> --- > >>> qapi-schema.json | 4 +++- > >>> vl.c | 1 + > >>> 2 files changed, 4 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/qapi-schema.json b/qapi-schema.json > >>> index db542f6..689ca8d 100644 > >>> --- a/qapi-schema.json > >>> +++ b/qapi-schema.json > >>> @@ -2861,11 +2861,13 @@ > >>> # > >>> # @default: #optional whether the machine is default > >>> # > >>> +# @cpu-max: maximum number of CPUs supported by the machine type > >> Typically, when adding a field in a later version than the original > >> introduction of the datatype, we add '(since 1.5)' to make it obvious > >> when to expect the field. However, as nothing (currently) enforces this > >> rule, I think such an addition is minor enough that it wouldn't > >> invalidate the use of my: > > Oh, it turns out I was making some confusion with this patch and > > didn't realize it was extending the query-machines command. > > > > I don't mean there's anything wrong with it, but my question is: doesn't > > this patch invalidates query-cpu-max? > > Not really, the query-cpu-max shows maximum number of CPUs supported per > currently running machine (machine type) however the extension to > query-machines shows the maximum number of CPUs supported per each of > the displayed machine types. This usually doesn't matter on x86 > architectures however it does matter on ARM, for example, as ARM has > some CPU models supporting up to 4 CPUs (highbank model) whereas most of > the ARM processors does have only one CPU. Can't we eliminate the query-cpu-max command if we extend the query-machines command to show which machine type is in use?
On 04/09/13 15:06, Luiz Capitulino wrote: > On Mon, 08 Apr 2013 11:14:32 -0600 > Eric Blake <eblake@redhat.com> wrote: > >> On 04/08/2013 10:41 AM, Michal Novotny wrote: >>> Alter the query-machines QMP command to output information about >>> maximum number of CPUs for each machine type with default value >>> set to 1 in case the number of max_cpus is not set. >>> >>> Signed-off-by: Michal Novotny <minovotn@redhat.com> >>> --- >>> qapi-schema.json | 4 +++- >>> vl.c | 1 + >>> 2 files changed, 4 insertions(+), 1 deletion(-) >>> >>> diff --git a/qapi-schema.json b/qapi-schema.json >>> index db542f6..689ca8d 100644 >>> --- a/qapi-schema.json >>> +++ b/qapi-schema.json >>> @@ -2861,11 +2861,13 @@ >>> # >>> # @default: #optional whether the machine is default >>> # >>> +# @cpu-max: maximum number of CPUs supported by the machine type >> >> Typically, when adding a field in a later version than the original >> introduction of the datatype, we add '(since 1.5)' to make it obvious >> when to expect the field. However, as nothing (currently) enforces this >> rule, I think such an addition is minor enough that it wouldn't >> invalidate the use of my: > > Oh, it turns out I was making some confusion with this patch and > didn't realize it was extending the query-machines command. > > I don't mean there's anything wrong with it, but my question is: doesn't > this patch invalidates query-cpu-max? Unfortunately, for libvirt query-cpu-max isn't really usable as it needs us to start qemu with the correct machine type. This would increase overhead as we would need to start the qemu process with a safe number of cpus, use query-cpu-max and then restart the process. The information added in the query-machines output can on the other hand be cached (we are already doing this for the machine types) and used later from the cache without increasing overhead. So yes, I think it invalidates query-cpu-max and it can be removed in case it wasn't released. Peter > > PS: I can add the '(since 1.5)' line myself. > >> >> Reviewed-by: Eric Blake <eblake@redhat.com> >> > >
On 04/09/2013 03:15 PM, Luiz Capitulino wrote: > On Tue, 09 Apr 2013 15:09:21 +0200 > Michal Novotny <minovotn@redhat.com> wrote: > >> On 04/09/2013 03:06 PM, Luiz Capitulino wrote: >>> On Mon, 08 Apr 2013 11:14:32 -0600 >>> Eric Blake <eblake@redhat.com> wrote: >>> >>>> On 04/08/2013 10:41 AM, Michal Novotny wrote: >>>>> Alter the query-machines QMP command to output information about >>>>> maximum number of CPUs for each machine type with default value >>>>> set to 1 in case the number of max_cpus is not set. >>>>> >>>>> Signed-off-by: Michal Novotny <minovotn@redhat.com> >>>>> --- >>>>> qapi-schema.json | 4 +++- >>>>> vl.c | 1 + >>>>> 2 files changed, 4 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/qapi-schema.json b/qapi-schema.json >>>>> index db542f6..689ca8d 100644 >>>>> --- a/qapi-schema.json >>>>> +++ b/qapi-schema.json >>>>> @@ -2861,11 +2861,13 @@ >>>>> # >>>>> # @default: #optional whether the machine is default >>>>> # >>>>> +# @cpu-max: maximum number of CPUs supported by the machine type >>>> Typically, when adding a field in a later version than the original >>>> introduction of the datatype, we add '(since 1.5)' to make it obvious >>>> when to expect the field. However, as nothing (currently) enforces this >>>> rule, I think such an addition is minor enough that it wouldn't >>>> invalidate the use of my: >>> Oh, it turns out I was making some confusion with this patch and >>> didn't realize it was extending the query-machines command. >>> >>> I don't mean there's anything wrong with it, but my question is: doesn't >>> this patch invalidates query-cpu-max? >> Not really, the query-cpu-max shows maximum number of CPUs supported per >> currently running machine (machine type) however the extension to >> query-machines shows the maximum number of CPUs supported per each of >> the displayed machine types. This usually doesn't matter on x86 >> architectures however it does matter on ARM, for example, as ARM has >> some CPU models supporting up to 4 CPUs (highbank model) whereas most of >> the ARM processors does have only one CPU. > Can't we eliminate the query-cpu-max command if we extend the > query-machines command to show which machine type is in use? It may be useful as query-cpu-max is showing maximum number of CPUs supported per machine type QEMU currently emulates. We don't have to know the machine type and look for this number manually in the query-machines output if we have query-cpu-max. We would have to both know the machine type and look for the number manually to get max-cpu count for currently running machine if we get rid of query-cpu-max command. Whether something will use the value of CPU-max for currently running machine (query-cpu-max output) is another question. Michal
On Tue, 09 Apr 2013 15:32:57 +0200 Michal Novotny <minovotn@redhat.com> wrote: > > On 04/09/2013 03:15 PM, Luiz Capitulino wrote: > > On Tue, 09 Apr 2013 15:09:21 +0200 > > Michal Novotny <minovotn@redhat.com> wrote: > > > >> On 04/09/2013 03:06 PM, Luiz Capitulino wrote: > >>> On Mon, 08 Apr 2013 11:14:32 -0600 > >>> Eric Blake <eblake@redhat.com> wrote: > >>> > >>>> On 04/08/2013 10:41 AM, Michal Novotny wrote: > >>>>> Alter the query-machines QMP command to output information about > >>>>> maximum number of CPUs for each machine type with default value > >>>>> set to 1 in case the number of max_cpus is not set. > >>>>> > >>>>> Signed-off-by: Michal Novotny <minovotn@redhat.com> > >>>>> --- > >>>>> qapi-schema.json | 4 +++- > >>>>> vl.c | 1 + > >>>>> 2 files changed, 4 insertions(+), 1 deletion(-) > >>>>> > >>>>> diff --git a/qapi-schema.json b/qapi-schema.json > >>>>> index db542f6..689ca8d 100644 > >>>>> --- a/qapi-schema.json > >>>>> +++ b/qapi-schema.json > >>>>> @@ -2861,11 +2861,13 @@ > >>>>> # > >>>>> # @default: #optional whether the machine is default > >>>>> # > >>>>> +# @cpu-max: maximum number of CPUs supported by the machine type > >>>> Typically, when adding a field in a later version than the original > >>>> introduction of the datatype, we add '(since 1.5)' to make it obvious > >>>> when to expect the field. However, as nothing (currently) enforces this > >>>> rule, I think such an addition is minor enough that it wouldn't > >>>> invalidate the use of my: > >>> Oh, it turns out I was making some confusion with this patch and > >>> didn't realize it was extending the query-machines command. > >>> > >>> I don't mean there's anything wrong with it, but my question is: doesn't > >>> this patch invalidates query-cpu-max? > >> Not really, the query-cpu-max shows maximum number of CPUs supported per > >> currently running machine (machine type) however the extension to > >> query-machines shows the maximum number of CPUs supported per each of > >> the displayed machine types. This usually doesn't matter on x86 > >> architectures however it does matter on ARM, for example, as ARM has > >> some CPU models supporting up to 4 CPUs (highbank model) whereas most of > >> the ARM processors does have only one CPU. > > Can't we eliminate the query-cpu-max command if we extend the > > query-machines command to show which machine type is in use? > > It may be useful as query-cpu-max is showing maximum number of CPUs > supported per machine type QEMU currently emulates. We don't have to > know the machine type and look for this number manually in the > query-machines output if we have query-cpu-max. QMP is a machine protocol, "manual" in that context is not a problem. It's actually wanted. > We would have to both > know the machine type and look for the number manually to get max-cpu > count for currently running machine if we get rid of query-cpu-max command. > > Whether something will use the value of CPU-max for currently running > machine (query-cpu-max output) is another question. What you mean by that? Why are we adding a command if we don't even know if it's going to be used? If I remember correctly, it was said that libivrt was asking for this command. If this is not the case let's drop it, because the command is bad (ie. this should be done through QOM). I've applied this patch, but again, if query-cpu-max is not required by any QMP user, please post patches reverting it.
On 04/09/2013 03:42 PM, Luiz Capitulino wrote: > On Tue, 09 Apr 2013 15:32:57 +0200 > Michal Novotny <minovotn@redhat.com> wrote: > >> On 04/09/2013 03:15 PM, Luiz Capitulino wrote: >>> On Tue, 09 Apr 2013 15:09:21 +0200 >>> Michal Novotny <minovotn@redhat.com> wrote: >>> >>>> On 04/09/2013 03:06 PM, Luiz Capitulino wrote: >>>>> On Mon, 08 Apr 2013 11:14:32 -0600 >>>>> Eric Blake <eblake@redhat.com> wrote: >>>>> >>>>>> On 04/08/2013 10:41 AM, Michal Novotny wrote: >>>>>>> Alter the query-machines QMP command to output information about >>>>>>> maximum number of CPUs for each machine type with default value >>>>>>> set to 1 in case the number of max_cpus is not set. >>>>>>> >>>>>>> Signed-off-by: Michal Novotny <minovotn@redhat.com> >>>>>>> --- >>>>>>> qapi-schema.json | 4 +++- >>>>>>> vl.c | 1 + >>>>>>> 2 files changed, 4 insertions(+), 1 deletion(-) >>>>>>> >>>>>>> diff --git a/qapi-schema.json b/qapi-schema.json >>>>>>> index db542f6..689ca8d 100644 >>>>>>> --- a/qapi-schema.json >>>>>>> +++ b/qapi-schema.json >>>>>>> @@ -2861,11 +2861,13 @@ >>>>>>> # >>>>>>> # @default: #optional whether the machine is default >>>>>>> # >>>>>>> +# @cpu-max: maximum number of CPUs supported by the machine type >>>>>> Typically, when adding a field in a later version than the original >>>>>> introduction of the datatype, we add '(since 1.5)' to make it obvious >>>>>> when to expect the field. However, as nothing (currently) enforces this >>>>>> rule, I think such an addition is minor enough that it wouldn't >>>>>> invalidate the use of my: >>>>> Oh, it turns out I was making some confusion with this patch and >>>>> didn't realize it was extending the query-machines command. >>>>> >>>>> I don't mean there's anything wrong with it, but my question is: doesn't >>>>> this patch invalidates query-cpu-max? >>>> Not really, the query-cpu-max shows maximum number of CPUs supported per >>>> currently running machine (machine type) however the extension to >>>> query-machines shows the maximum number of CPUs supported per each of >>>> the displayed machine types. This usually doesn't matter on x86 >>>> architectures however it does matter on ARM, for example, as ARM has >>>> some CPU models supporting up to 4 CPUs (highbank model) whereas most of >>>> the ARM processors does have only one CPU. >>> Can't we eliminate the query-cpu-max command if we extend the >>> query-machines command to show which machine type is in use? >> It may be useful as query-cpu-max is showing maximum number of CPUs >> supported per machine type QEMU currently emulates. We don't have to >> know the machine type and look for this number manually in the >> query-machines output if we have query-cpu-max. > QMP is a machine protocol, "manual" in that context is not a problem. > It's actually wanted. By manually in this context I mean if you have already running machine and you know the machine type then you have to run query-machines and look for your CPU type if you want know maximum number of CPUs supported by this machine type. > >> We would have to both >> know the machine type and look for the number manually to get max-cpu >> count for currently running machine if we get rid of query-cpu-max command. >> >> Whether something will use the value of CPU-max for currently running >> machine (query-cpu-max output) is another question. > What you mean by that? Why are we adding a command if we don't even know > if it's going to be used? The original reason was to allow libvirt to know max. number of CPUs however libvirt queries the machines and puts the aliases and CPU models into capabilities which is basically reason why we could drop query-cpu-max command as new implementation was necessary (the one extending MachineInfo by cpu-max). > > If I remember correctly, it was said that libivrt was asking for this > command. If this is not the case let's drop it, because the command is > bad (ie. this should be done through QOM). Originally yes however the implementation of extending MachineInfo seems to be better for them so they don't need query-cpu-max anymore. > > I've applied this patch, but again, if query-cpu-max is not required by > any QMP user, please post patches reverting it. Ok, I will create a revert patch and I'll send it. Michal
diff --git a/qapi-schema.json b/qapi-schema.json index db542f6..689ca8d 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -2861,11 +2861,13 @@ # # @default: #optional whether the machine is default # +# @cpu-max: maximum number of CPUs supported by the machine type +# # Since: 1.2.0 ## { 'type': 'MachineInfo', 'data': { 'name': 'str', '*alias': 'str', - '*is-default': 'bool' } } + '*is-default': 'bool', 'cpu-max': 'int' } } ## # @query-machines: diff --git a/vl.c b/vl.c index a8bba04..c05b3d3 100644 --- a/vl.c +++ b/vl.c @@ -1617,6 +1617,7 @@ MachineInfoList *qmp_query_machines(Error **errp) } info->name = g_strdup(m->name); + info->cpu_max = !m->max_cpus ? 1 : m->max_cpus; entry = g_malloc0(sizeof(*entry)); entry->value = info;
Alter the query-machines QMP command to output information about maximum number of CPUs for each machine type with default value set to 1 in case the number of max_cpus is not set. Signed-off-by: Michal Novotny <minovotn@redhat.com> --- qapi-schema.json | 4 +++- vl.c | 1 + 2 files changed, 4 insertions(+), 1 deletion(-)