[libvirt] [PATCH v2] Pin guest to memory node on NUMA system

Shivaprasad bhat shivaprasadbhat at gmail.com
Tue Nov 26 14:27:06 UTC 2013


Thanks Martin. I use stgit. I need to figure out how to put the notes
in the format you mentioned.

Sending you the V3 addressing your comments.

Regards,
Shiva

On Mon, Nov 25, 2013 at 3:01 PM, Martin Kletzander <mkletzan at redhat.com> wrote:
> On Tue, Nov 19, 2013 at 09:36:49AM -0500, Shivaprasad G Bhat wrote:
>> Version 2:
>> Fixed the string formatting errors in v1.
>>
>> Version 1:
>> The patch contains the fix for defect 1009880 reported at redhat bugzilla.
>>
>
> Version changes are great to have, but it's good to add them as a
> 'footnote' or as 'notes' (separated from the commit with three dashes
> on a line, i.e. '---\n').  You can also use git-notes(1) and then use
> git-format-patch(1) with the '--notes' option, which adds it there
> properly.
>
>> The root cause is, ever since the subcpusets(vcpu,emulator) were introduced, the paren cpuset cannot be modified to remove the nodes that are in use by the subcpusets.
>> The fix is to break the memory node modification into three steps as to assign new nodes into the parent first. Change the nodes in the child nodes. Then remove the old nodes on the parent node.
>>
>
> Please make sure your EDITOR wraps lines, so it's better readable and
> it also looks better in git log.
>
>> Signed-off-by: Shivaprasad G Bhat <sbhat at linux.vnet.ibm.com>
>> ---
>>  src/qemu/qemu_driver.c |  129 ++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 129 insertions(+)
>>
>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
>> index e8bc04d..2435b75 100644
>> --- a/src/qemu/qemu_driver.c
>> +++ b/src/qemu/qemu_driver.c
>> @@ -8171,7 +8171,11 @@ qemuDomainSetNumaParameters(virDomainPtr dom,
>>              }
>>          } else if (STREQ(param->field, VIR_DOMAIN_NUMA_NODESET)) {
>>              virBitmapPtr nodeset = NULL;
>> +            virBitmapPtr old_nodeset = NULL;
>> +            virBitmapPtr temp_nodeset = NULL;
>>              char *nodeset_str = NULL;
>> +            char *old_nodeset_str = NULL;
>> +            char *temp_nodeset_str = NULL;
>>
>>              if (virBitmapParse(params[i].value.s,
>>                                 0, &nodeset,
>> @@ -8181,6 +8185,10 @@ qemuDomainSetNumaParameters(virDomainPtr dom,
>>              }
>>
>>              if (flags & VIR_DOMAIN_AFFECT_LIVE) {
>> +                size_t j;
>> +                virCgroupPtr cgroup_vcpu = NULL;
>> +                virCgroupPtr cgroup_emulator = NULL;
>> +
>>                  if (vm->def->numatune.memory.mode !=
>>                      VIR_DOMAIN_NUMATUNE_MEM_STRICT) {
>>                      virReportError(VIR_ERR_OPERATION_INVALID, "%s",
>> @@ -8200,7 +8208,128 @@ qemuDomainSetNumaParameters(virDomainPtr dom,
>>                      continue;
>>                  }
>>
>> +                if (virCgroupGetCpusetMems(priv->cgroup, &old_nodeset_str) < 0) {
>> +                    virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>> +                                   _("Failed to get current system nodeset values"));
>
> No need to report second error since virCgroup...() already set the error.
>
>> +                    virBitmapFree(nodeset);
>> +                    VIR_FREE(nodeset_str);
>> +                    ret = -1;
>> +                    continue;
>> +                }
>> +
>> +                if (virBitmapParse(old_nodeset_str, 0, &old_nodeset,
>> +                                   VIR_DOMAIN_CPUMASK_LEN) < 0) {
>> +                    virBitmapFree(nodeset);
>> +                    VIR_FREE(nodeset_str);
>> +                    VIR_FREE(old_nodeset_str);
>> +                    ret = -1;
>> +                    continue;
>> +                }
>> +
>> +                if ((temp_nodeset = virBitmapNewCopy(old_nodeset)) == NULL) {
>> +                    virBitmapFree(nodeset);
>> +                    VIR_FREE(nodeset_str);
>> +                    virBitmapFree(old_nodeset);
>> +                    VIR_FREE(old_nodeset_str);
>> +                    ret = -1;
>> +                    continue;
>
> Just skimming through, I see a lot of unnecessary code duplication
> here.  Can you break it to different function?  Or rework the code to
> free/clean the data in one place, since there is more than a few lines
> of code in this workpath?
>
> Martin




More information about the libvir-list mailing list