Re: [Qemu-devel] [PATCH v1] numa: report all DIMM/NVDIMMs as plugged memory

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 27 Jun 2018 15:38:23 +0200
David Hildenbrand <david@redhat.com> wrote:

> On 27.06.2018 13:21, Igor Mammedov wrote:
> > On Fri, 22 Jun 2018 16:40:45 +0200
> > David Hildenbrand <david@redhat.com> wrote:
> >   
> >> Right now, there is some inconsistency between hotplugged and
> >> coldplugged memory. DIMMs added via "-device" result in different stats
> >> than DIMMs added using "device_add".
> >>
> >> E.g.
> >>     [...]
> >>     -numa node,nodeid=0,cpus=0-1 -numa node,nodeid=1,cpus=2-3 \
> >>     -m 4G,maxmem=20G,slots=2 \
> >>     -object memory-backend-ram,id=mem0,size=8G \
> >>     -device pc-dimm,id=dimm0,memdev=mem0 \
> >>     -object memory-backend-ram,id=mem1,size=8G \
> >>     -device nvdimm,id=dimm1,memdev=mem1,node=1
> >>
> >> Results in NUMA info
> >>     (qemu) info numa
> >>     info numa
> >>     2 nodes
> >>     node 0 cpus: 0 1
> >>     node 0 size: 10240 MB
> >>     node 0 plugged: 0 MB
> >>     node 1 cpus: 2 3
> >>     node 1 size: 10240 MB
> >>     node 1 plugged: 0 MB  
> > ...   
> >> But in memory size summary:
> >>     (qemu) info memory_size_summary
> >>     info memory_size_summary
> >>     base memory: 4294967296
> >>     plugged memory: 17179869184  
> > this looks like right amount wrt used CLI,
> > is this supposed to be correct output or broken one?
> > ('but' implies incorrect one)  
> 
> 'but' just highlights the inconsistency here. As explained above, all
> dimms should be reported as plugged (hot and coldplugged).
> 
> So in my opinion "memory size summary" does the right thing right now.
maybe add to commit message that says what exactly is being fixed,
otherwise it's not clear what is expected/wrong beside of output being inconsistent.

> 
> >   
> >>
> >> Make this consistent by reporting all hot and coldplugged
> >> memory a.k.a. DIMM and NVDIMM as "plugged".
maybe mention 'info numa' and maybe QMP equivalent if it exists,
otherwise above text is a bit vague for bystander (could be /me|you in a day-month-year)

> >>
> >> Fixes: 31959e82fb0 ("hmp: extend "info numa" with hotplugged memory information")
> >> Signed-off-by: David Hildenbrand <david@redhat.com>
> >> ---
> >>  numa.c | 6 ++----
> >>  1 file changed, 2 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/numa.c b/numa.c
> >> index 94f758c757..5f6367b989 100644
> >> --- a/numa.c
> >> +++ b/numa.c
> >> @@ -566,10 +566,8 @@ static void numa_stat_memory_devices(NumaNodeMem node_mem[])
> >>  
> >>              if (pcdimm_info) {
> >>                  node_mem[pcdimm_info->node].node_mem += pcdimm_info->size;
> >> -                if (pcdimm_info->hotpluggable && pcdimm_info->hotplugged) {
> >> -                    node_mem[pcdimm_info->node].node_plugged_mem +=
> >> -                        pcdimm_info->size;
> >> -                }
> >> +                node_mem[pcdimm_info->node].node_plugged_mem +=
> >> +                    pcdimm_info->size;
> >>              }
> >>          }
> >>      }  
> >   
> 
>