On 03/06/2015 07:39 AM, Ján Tomko wrote:
On Thu, Mar 05, 2015 at 09:03:00PM -0500, John Ferlan wrote:
Depending on the flags passed, either attempt to return the active/live IOThread data for the domain or the config data.
The active/live path will call into the Monitor in order to get the IOThread data and then correlate the thread_id's returned from the monitor to the currently running system/threads in order to ascertain the affinity for each iothread_id.
The config path will map each of the configured IOThreads and return any configured iothreadspin data
Signed-off-by: John Ferlan <jferlan@redhat.com> --- src/qemu/qemu_driver.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 224 insertions(+)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index ffa4e19..d8a761d 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -5557,6 +5557,229 @@ qemuDomainGetMaxVcpus(virDomainPtr dom) VIR_DOMAIN_VCPU_MAXIMUM)); }
+static int +qemuDomainGetIOThreadsLive(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainIOThreadInfoPtr **info) +{ + qemuDomainObjPrivatePtr priv; + qemuMonitorIOThreadsInfoPtr *iothreads = NULL; + virDomainIOThreadInfoPtr *info_ret = NULL; + int niothreads = 0; + int maxcpu, hostcpus, maplen; + size_t i; + int ret = -1; + + if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY) < 0) + goto cleanup; + + if (!virDomainObjIsActive(vm)) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("cannot list IOThreads for an inactive domain")); + goto endjob; + } + + priv = vm->privateData; + if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_OBJECT_IOTHREAD)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("IOThreads not supported with this binary")); + goto endjob; + } + + qemuDomainObjEnterMonitor(driver, vm); + niothreads = qemuMonitorGetIOThreads(priv->mon, &iothreads); + if (qemuDomainObjExitMonitor(driver, vm) < 0) + goto endjob; + if (niothreads < 0) + goto endjob; + + /* Nothing to do */ + if (niothreads == 0) { + ret = 0; + goto endjob; + } + + if ((hostcpus = nodeGetCPUCount()) < 0) + goto endjob; + + maplen = VIR_CPU_MAPLEN(hostcpus);
The maplen is not needed. Just pass 'hostcpus' to 'virProcessGetAffinity' and it will generate a virBitmap of the right size, then virBitmapToData computes the correct maplen.
+ maxcpu = maplen * 8; + if (maxcpu > hostcpus)
These two lines are redundant. If maplen * 8 < hostcpus, then VIR_CPU_MAPLEN is flawed, because the map does not hold at least hostcpus bits. If maplen * 8 >= hostcpus, the value of hostcpus is used.
Hmm... I'll have to go back and look again as this was pretty much following the VcpuPin or EmulatorPin examples with a touch of GetCPUMap since this code returns the cpumap rather than expecting one on input.
+ maxcpu = hostcpus;
+ + if (VIR_ALLOC_N(info_ret, niothreads) < 0) + goto endjob; + + for (i = 0; i < niothreads; i++) { + virBitmapPtr map = NULL; + unsigned char *tmpmap = NULL; + int tmpmaplen = 0; + + if (VIR_ALLOC(info_ret[i]) < 0) + goto endjob; + + if (virStrToLong_ui(iothreads[i]->name + strlen("iothread"), NULL, 10, + &info_ret[i]->iothread_id) < 0) + goto endjob; + + if (VIR_ALLOC_N(info_ret[i]->cpumap, maplen) < 0) + goto endjob; + + if (virProcessGetAffinity(iothreads[i]->thread_id, &map, maxcpu) < 0) + goto endjob; + + virBitmapToData(map, &tmpmap, &tmpmaplen);
+ if (tmpmaplen > maplen) + tmpmaplen = maplen;
This is equivalent to: if (VIR_CPU_MAPLEN(hostcpus) > VIR_CPU_MAPLEN(hostcpus))
+ memcpy(info_ret[i]->cpumap, tmpmap, tmpmaplen); + info_ret[i]->cpumaplen = tmpmaplen; + + VIR_FREE(tmpmap); + virBitmapFree(map); + } + + *info = info_ret; + info_ret = NULL; + ret = niothreads; + + endjob: + qemuDomainObjEndJob(driver, vm); + + cleanup: + if (info_ret) { + for (i = 0; i < niothreads; i++) + virDomainIOThreadsInfoFree(info_ret[i]); + VIR_FREE(info_ret); + } + if (iothreads) { + for (i = 0; i < niothreads; i++) + qemuMonitorIOThreadsInfoFree(iothreads[i]); + VIR_FREE(iothreads); + } + + return ret; +} + +static int +qemuDomainGetIOThreadsConfig(virDomainDefPtr targetDef, + virDomainIOThreadInfoPtr **info) +{ + virDomainIOThreadInfoPtr *info_ret = NULL; + virDomainVcpuPinDefPtr *iothreadspin_list; + virBitmapPtr cpumask = NULL; + unsigned char *cpumap; + int maxcpu, hostcpus, maplen; + size_t i, pcpu; + bool pinned; + int ret = -1; + + if (targetDef->iothreads == 0) + return 0; + + if ((hostcpus = nodeGetCPUCount()) < 0) + goto cleanup; + + maplen = VIR_CPU_MAPLEN(hostcpus); + maxcpu = maplen * 8; + if (maxcpu > hostcpus) + maxcpu = hostcpus;
Same redunancy here.
+ + if (VIR_ALLOC_N(info_ret, targetDef->iothreads) < 0) + goto cleanup; + + for (i = 0; i < targetDef->iothreads; i++) { + if (VIR_ALLOC(info_ret[i]) < 0) + goto cleanup; + + /* IOThreads being counting at 1 */ + info_ret[i]->iothread_id = i + 1; +
As I mentioned in my reply to v3: https://www.redhat.com/archives/libvir-list/2015-March/msg00249.html this really would look readable with virBitmapToData. I meant something like this:
pininfo = virDomainVcpuPinFindByVcpu(targetDef->cputune.iothreadspin,); if (!pininfo) { bitmap = virBitmapNew(hostcpus); virBitmapSetAllBits(bitmap); pininfo = bitmap; } virBitmapToData(pininfo, info[i]->cpumap, info[i]->cpumaplen)
I'll revisit, but again I was keeping in line with other examples.
+ if (VIR_ALLOC_N(info_ret[i]->cpumap, maplen) < 0) + goto cleanup; + + /* Initialize the cpumap */ + info_ret[i]->cpumaplen = maplen; + memset(info_ret[i]->cpumap, 0xff, maplen); + if (maxcpu % 8) + info_ret[i]->cpumap[maplen - 1] &= (1 << maxcpu % 8) - 1;
+ } + + /* If iothreadspin setting exists, there are unused physical cpus */ + iothreadspin_list = targetDef->cputune.iothreadspin; + for (i = 0; i < targetDef->cputune.niothreadspin; i++) { + /* vcpuid is the iothread_id... + * iothread_id is the index into info_ret + 1, so we can + * assume that the info_ret index we want is vcpuid - 1 + */ + cpumap = info_ret[iothreadspin_list[i]->vcpuid - 1]->cpumap; + cpumask = iothreadspin_list[i]->cpumask; + + for (pcpu = 0; pcpu < maxcpu; pcpu++) { + if (virBitmapGetBit(cpumask, pcpu, &pinned) < 0) + goto cleanup; + if (!pinned) + VIR_UNUSE_CPU(cpumap, pcpu); + } + }
This is essentially an open-coded version of virBitmapToData.
I'll address these in an update John