On 03/06/2015 04:46 AM, Daniel P. Berrange wrote:
> On Thu, Mar 05, 2015 at 09:03:02PM -0500, John Ferlan wrote:
>> Add virDomainGetIOThreadPin to fetch the pinned CPU affinity map
>> for one IOThread.
>>
>> Add virDomainPinIOThread to allow setting the CPU affinity for a
>> specific IOThread.
>>
>> Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
>> ---
>> include/libvirt/libvirt-domain.h | 10 +++
>> src/driver-hypervisor.h | 16 +++++
>> src/libvirt-domain.c | 152 +++++++++++++++++++++++++++++++++++++++
>> src/libvirt_public.syms | 2 +
>> 4 files changed, 180 insertions(+)
>>
>> diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
>> index 9487b80..fc35cd2 100644
>> --- a/include/libvirt/libvirt-domain.h
>> +++ b/include/libvirt/libvirt-domain.h
>> @@ -1609,6 +1609,16 @@ void virDomainIOThreadsInfoFree(virDomainIOThreadInfoPtr info);
>> int virDomainGetIOThreadsInfo(virDomainPtr domain,
>> virDomainIOThreadInfoPtr **info,
>> unsigned int flags);
>> +int virDomainGetIOThreadPin (virDomainPtr domain,
>> + unsigned int iothread_id,
>> + unsigned char *cpumap,
>> + int maplen,
>> + unsigned int flags);
>
> Isn't the GetIOThreadsInfo method & struct already reporting the pinning
> info for all current IO threads ? I'm not sure what the difference is
> between what GetIOThreadsInfo and GetIOThreadPin is ?
>
> +struct _virDomainIOThreadInfo {
> + unsigned int iothread_id; /* IOThread ID */
> + unsigned char *cpumap; /* CPU map for thread. A pointer to an */
> + /* array of real CPUs (in 8-bit bytes) */
> + int cpumaplen; /* cpumap size */
> +};
>
> These fields match all the parameters in GetIOThreadPin, so it seems adding a
> GetIOThreadPin is redundant,
>
>
Yes - although based on reviews from yesterday it wasn't totally clear
if having a GetIOThreadPin in addition to GetIOThreadsInfo was
requested, so I added it to be "safe", but can remove it.
There is a GetVcpus and a GetVcpuPinInfo and the IOThreads code mirrors
that.
Tks -
John
>> +int virDomainPinIOThread(virDomainPtr domain,
>> + unsigned int iothread_id,
>> + unsigned char *cpumap,
>> + int maplen,
>> + unsigned int flags);
>
> This is fine though
>
>
>> +/**
>> + * virDomainPinIOThread:
>> + * @domain: a domain object
>> + * @iothread_id: either the thread_id to modify or a count of IOThreads
>> + * to be added or removed from the domain depending on the @flags setting
>
> This can be updated now.
>
>> + * @cpumap: pointer to a bit map of real CPUs (in 8-bit bytes) (IN)
>> + * Each bit set to 1 means that corresponding CPU is usable.
>> + * Bytes are stored in little-endian order: CPU0-7, 8-15...
>> + * In each byte, lowest CPU number is least significant bit.
>> + * @maplen: number of bytes in cpumap, from 1 up to size of CPU map in
>> + * underlying virtualization system (Xen...).
>> + * If maplen < size, missing bytes are set to zero.
>> + * If maplen > size, failure code is returned.
>> + * @flags: bitwise-OR of virDomainModificationImpact
>> + *
>> + * Dynamically change the real CPUs which can be allocated to an IOThread.
>> + * This function may require privileged access to the hypervisor.
>> + *
>> + * @flags may include VIR_DOMAIN_AFFECT_LIVE or VIR_DOMAIN_AFFECT_CONFIG.
>> + * Both flags may be set.
>> + * If VIR_DOMAIN_AFFECT_LIVE is set, the change affects a running domain
>> + * and may fail if domain is not alive.
>> + * If VIR_DOMAIN_AFFECT_CONFIG is set, the change affects persistent state,
>> + * and will fail for transient domains. If neither flag is specified (that is,
>> + * @flags is VIR_DOMAIN_AFFECT_CURRENT), then an inactive domain modifies
>> + * persistent setup, while an active domain is hypervisor-dependent on whether
>> + * just live or both live and persistent state is changed.
>> + * Not all hypervisors can support all flag combinations.
>> + *
>> + * See also virDomainGetIOThreadsInfo for querying this information.
>> + *
>> + * Returns 0 in case of success, -1 in case of failure.
>> + */
>> +int
>> +virDomainPinIOThread(virDomainPtr domain,
>> + unsigned int iothread_id,
>> + unsigned char *cpumap,
>> + int maplen,
>> + unsigned int flags)
>> +{
>> + virConnectPtr conn;
>> +
>> + VIR_DOMAIN_DEBUG(domain, "iothread_id=%u, cpumap=%p, maplen=%d",
>> + iothread_id, cpumap, maplen);
>> +
>> + virResetLastError();
>> +
>> + virCheckDomainReturn(domain, -1);
>> + conn = domain->conn;
>> +
>> + virCheckReadOnlyGoto(conn->flags, error);
>> + if ((unsigned short) iothread_id != iothread_id) {
>> + virReportError(VIR_ERR_OVERFLOW, _("input too large: %u"),
>> + iothread_id);
>> + goto error;
>> + }
>> + virCheckPositiveArgGoto(iothread_id, error);
>> + virCheckNonNullArgGoto(cpumap, error);
>> + virCheckPositiveArgGoto(maplen, error);
>> +
>> + if (conn->driver->domainPinIOThread) {
>> + int ret;
>> + ret = conn->driver->domainPinIOThread(domain, iothread_id,
>> + cpumap, maplen, flags);
>> + if (ret < 0)
>> + goto error;
>> + return ret;
>> + }
>> +
>> + virReportUnsupportedError();
>> +
>> + error:
>> + virDispatchError(domain->conn);
>> + return -1;
>> +}
>
> Regards,
> Daniel
>
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