[libvirt] [PATCHv7 17/18] qemu: Report cache occupancy (CMT) with domstats
John Ferlan
jferlan at redhat.com
Mon Nov 5 20:04:09 UTC 2018
On 10/22/18 4:01 AM, Wang Huaqiang wrote:
> Adding the interface in qemu to report CMT statistic information
> through command 'virsh domstats --cpu-total'.
>
> Below is a typical output:
>
> # virsh domstats 1 --cpu-total
> Domain: 'ubuntu16.04-base'
> ...
> cpu.cache.monitor.count=2
> cpu.cache.monitor.0.name=vcpus_1
> cpu.cache.monitor.0.vcpus=1
> cpu.cache.monitor.0.bank.count=2
> cpu.cache.monitor.0.bank.0.id=0
> cpu.cache.monitor.0.bank.0.bytes=4505600
> cpu.cache.monitor.0.bank.1.id=1
> cpu.cache.monitor.0.bank.1.bytes=5586944
> cpu.cache.monitor.1.name=vcpus_4-6
> cpu.cache.monitor.1.vcpus=4,5,6
> cpu.cache.monitor.1.bank.count=2
> cpu.cache.monitor.1.bank.0.id=0
> cpu.cache.monitor.1.bank.0.bytes=17571840
> cpu.cache.monitor.1.bank.1.id=1
> cpu.cache.monitor.1.bank.1.bytes=29106176
>
> Signed-off-by: Wang Huaqiang <huaqiang.wang at intel.com>
> ---
> src/libvirt-domain.c | 9 ++
> src/libvirt_private.syms | 1 +
> src/qemu/qemu_driver.c | 229 +++++++++++++++++++++++++++++++++++++++++++++++
> src/util/virresctrl.c | 130 +++++++++++++++++++++++++++
> src/util/virresctrl.h | 12 +++
> 5 files changed, 381 insertions(+)
>
I have a feeling I'll be asking for this to be split up a bit, but let's
see... There's *util, *qemu, and *API code in the same patch.
> diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
> index 7690339..4895f9f 100644
> --- a/src/libvirt-domain.c
> +++ b/src/libvirt-domain.c
> @@ -11345,6 +11345,15 @@ virConnectGetDomainCapabilities(virConnectPtr conn,
> * "cpu.user" - user cpu time spent in nanoseconds as unsigned long long.
> * "cpu.system" - system cpu time spent in nanoseconds as unsigned long
> * long.
> + * "cpu.cache.monitor.count" - tocal cache monitoring groups
> + * "cpu.cache.monitor.M.name" - name of cache monitoring group 'M'
> + * "cpu.cache.monitor.M.vcpus" - vcpus for cache monitoring group 'M'
> + * "cpu.cache.monitor.M.bank.count" - total bank number of cache monitoring
> + * group 'M'
> + * "cpu.cache.monitor.M.bank.N.id" - OS assigned cache bank id for cache
> + * 'N' in cache monitoring group 'M'
> + * "cpu.cache.monitor.M.bank.N.bytes" - monitor's cache occupancy of cache
> + * bank 'N' in cache monitoring group 'M'
> *
> * VIR_DOMAIN_STATS_BALLOON:
> * Return memory balloon device information.
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 91801ed..4551767 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -2683,6 +2683,7 @@ virResctrlInfoNew;
> virResctrlMonitorAddPID;
> virResctrlMonitorCreate;
> virResctrlMonitorDeterminePath;
> +virResctrlMonitorGetCacheOccupancy;
> virResctrlMonitorGetID;
> virResctrlMonitorIsRunning;
> virResctrlMonitorNew;
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 12a5f8f..9828118 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -102,6 +102,7 @@
> #include "virnuma.h"
> #include "dirname.h"
> #include "netdev_bandwidth_conf.h"
> +#include "c-ctype.h"
Ahh.. this one's a red flag... Says to me that something should move to
a util function...
>
> #define VIR_FROM_THIS VIR_FROM_QEMU
>
> @@ -19698,6 +19699,230 @@ typedef enum {
> #define HAVE_JOB(flags) ((flags) & QEMU_DOMAIN_STATS_HAVE_JOB)
>
>
> +/* In terms of the output of virBitmapFormat, both '1-3' and '1,3' are valid
> + * outputs and represent different vcpu set. But it is not easy to
> + * differentiate these two vcpu set formats at first glance.
> + *
> + * This function could be used to clear this ambiguity, it substitutes all '-'
> + * with ',' while generates semantically correct vcpu set.
> + * e.g. vcpu set string '1-3' will be replaced by string '1,2,3'. */
> +static char *
> +qemuDomainVcpuFormatHelper(const char *vcpus)
> +{
> + size_t i = 0;
> + int last = 0;
> + int start = 0;
> + char * tmp = NULL;
> + bool firstnum = true;
> + const char *cur = vcpus;
> + virBuffer buf = VIR_BUFFER_INITIALIZER;
> + char *ret = NULL;
> +
> + if (virStringIsEmpty(cur))
> + return NULL;
> +
> + while (*cur != '\0') {
> + if (!c_isdigit(*cur))
Explains the #include, but in the long run, I don't think this method is
worth the effort since all you're doing is printing the format in the
output. Is there other libvirt generated output for cpu stats that does
a similar conversion? If so, share code, if not drop this.
No need to rearrange the range someone else entered and we've
succesfully parsed in some manner. I think the output should look like
the XML output unless there's some compelling reason to change it which
I don't see.
>From above the:
> cpu.cache.monitor.1.name=vcpus_4-6
> cpu.cache.monitor.1.vcpus=4,5,6
would then be:
> cpu.cache.monitor.1.name=vcpus_4-6
> cpu.cache.monitor.1.vcpus=4-6
right?
I don't even want to think about someone who does "7,4-6"...
> + goto cleanup;
> +
> + if (virStrToLong_i(cur, &tmp, 10, &start) < 0)
> + goto cleanup;
> + if (start < 0)
> + goto cleanup;
> +
> + cur = tmp;
> +
> + virSkipSpaces(&cur);
> +
> + if (*cur == ',' || *cur == 0) {
> + if (!firstnum)
> + virBufferAddChar(&buf, ',');
> + virBufferAsprintf(&buf, "%d", start);
> + firstnum = false;
> + } else if (*cur == '-') {
> + cur++;
> + virSkipSpaces(&cur);
> +
> + if (virStrToLong_i(cur, &tmp, 10, &last) < 0)
> + goto cleanup;
> +
> + if (last < start)
> + goto cleanup;
> + cur = tmp;
> +
> + for (i = start; i <= last; i++) {
> + if (!firstnum)
> +
> + virBufferAddChar(&buf, ',');
> + virBufferAsprintf(&buf, "%ld", i);
> + firstnum = 0;
> + }
> +
> + virSkipSpaces(&cur);
> + }
> +
> + if (*cur == ',') {
> + cur++;
> + virSkipSpaces(&cur);
> + } else if (*cur == 0) {
> + break;
> + } else {
> + goto cleanup;
> + }
> + }
> +
> + ret = virBufferContentAndReset(&buf);
> + cleanup:
> + virBufferFreeAndReset(&buf);
> + return ret;
> +}
> +
> +
> +static int
> +qemuDomainGetStatsCpuResource(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
> + virDomainObjPtr dom,
> + virDomainStatsRecordPtr record,
> + int *maxparams,
> + unsigned int privflags ATTRIBUTE_UNUSED,
> + virResctrlMonitorType restag)
Why bother passing ATTRIBUTE_UNUSED ?
> +{
> + char param_name[VIR_TYPED_PARAM_FIELD_LENGTH];
> + virDomainResctrlMonDefPtr domresmon = NULL;
> + virResctrlMonitorStatsPtr stats = NULL;
> + size_t nstats = 0;
since these are local to the:
+ for (j = 0; j < resctrl->nmonitors; j++) {
loop and there's local's in that for loop, maybe these two should move
there too...
> + virDomainResctrlDefPtr resctrl = NULL;
> + unsigned int nmonitors = 0;
> + unsigned int imonitor = 0;
> + const char *restype = NULL;
> + char *rawvcpus = NULL;
> + char *vcpus = NULL;
> + size_t i = 0;
> + size_t j = 0;
> + int ret = -1;
> +
> + if (!virDomainObjIsActive(dom))
> + return 0;
> +
> + if (restag == VIR_RESCTRL_MONITOR_TYPE_CACHE) {
> + restype = "cache";
> + } else {
> + VIR_DEBUG("Invalid CPU resource type");
VIR_DEBUG? virReportError would seem to be more appropriate. As I've
stated before there will be an error for some reason generated.
> + return -1;
> + }
> +
> + for (i = 0; i < dom->def->nresctrls; i++) {
> + resctrl = dom->def->resctrls[i];
> +
> + for (j = 0; j < resctrl->nmonitors; j++) {
> + domresmon = resctrl->monitors[j];
> + if (virResctrlMonitorIsRunning(domresmon->instance) &&
> + domresmon->tag == restag)
Knowing how heavy wait *IsRunning is, the order of checking should be
reversed at the very least.
> + nmonitors++;
> + }
> + }
> +
> + if (nmonitors) {
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "cpu.%s.monitor.count", restype);
> + if (virTypedParamsAddUInt(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + nmonitors) < 0)
> + goto cleanup;
> + }
All that above to ensure nmonitors == resctrl->nmonitors??? I think
there's a lot of unnecessary stuff.
> +
> + for (i = 0; i < dom->def->nresctrls; i++) {
> + resctrl = dom->def->resctrls[i];
> +
> + for (j = 0; j < resctrl->nmonitors; j++) {
> + size_t l = 0;
> + virResctrlMonitorPtr monitor = resctrl->monitors[j]->instance;
> + const char *id = virResctrlMonitorGetID(monitor);
> +
> + if (!id)
> + goto cleanup;
I would think you have other problems in this case. Besides there's no
error message associated with this.
> +
> + domresmon = resctrl->monitors[j];
> +
> + if (!virResctrlMonitorIsRunning(domresmon->instance))
> + continue;
Oh my one call for each iteration, ouch - highly inefficient.
> +
> + if (!(rawvcpus = virBitmapFormat(domresmon->vcpus)))
> + goto cleanup;
> +
> + vcpus = qemuDomainVcpuFormatHelper(rawvcpus);
> + if (!vcpus)
> + goto cleanup;
> +
> + if (virResctrlMonitorGetCacheOccupancy(monitor, &stats,
> + &nstats) < 0)
> + goto cleanup;
> +
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "cpu.%s.monitor.%d.name", restype, imonitor);
> + if (virTypedParamsAddString(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + id) < 0)
> + goto cleanup;
> +
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "cpu.%s.monitor.%d.vcpus", restype, imonitor);
> +
> + if (virTypedParamsAddString(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + vcpus) < 0)
> + goto cleanup;
> +
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "cpu.%s.monitor.%d.bank.count", restype, imonitor);
> + if (virTypedParamsAddUInt(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + nstats) < 0)
> + goto cleanup;
> +
> + for (l = 0; l < nstats; l++) {
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "cpu.%s.monitor.%d.bank.%ld.id",
> + restype, imonitor, l);
> + if (virTypedParamsAddUInt(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + stats[l].id) < 0)
> + goto cleanup;
> +
> +
> + snprintf(param_name, VIR_TYPED_PARAM_FIELD_LENGTH,
> + "cpu.%s.monitor.%d.bank.%ld.bytes",
> + restype, imonitor, l);
> + if (virTypedParamsAddUInt(&record->params,
> + &record->nparams,
> + maxparams,
> + param_name,
> + stats[l].val) < 0)
> + goto cleanup;
> + }
> +
> + VIR_FREE(stats);
nstats = 0;
too!
> + VIR_FREE(vcpus);
> + imonitor++;
> + }
> + }
> +
> + ret = 0;
> + cleanup:
> + VIR_FREE(vcpus);
> + return ret;
> +}
> +
> +
> static int
> qemuDomainGetStatsCpu(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
> virDomainObjPtr dom,
> @@ -19735,6 +19960,10 @@ qemuDomainGetStatsCpu(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
> return -1;
> }
>
> + if (qemuDomainGetStatsCpuResource(driver, dom, record, maxparams, privflags,
> + VIR_RESCTRL_MONITOR_TYPE_CACHE) < 0)
> + return -1;
> +
> return 0;
> }
>
> diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c
> index fa3e6e9..02e7095 100644
> --- a/src/util/virresctrl.c
> +++ b/src/util/virresctrl.c
> @@ -2713,3 +2713,133 @@ virResctrlMonitorIsRunning(virResctrlMonitorPtr monitor)
>
> return ret;
> }
> +
> +
> +static int
> +virResctrlMonitorStatsSorter(const void *a,
> + const void *b)
> +{
> + return ((virResctrlMonitorStatsPtr)a)->id
> + - ((virResctrlMonitorStatsPtr)b)->id;
> +}
> +
> +
> +/*
> + * virResctrlMonitorGetStats
> + *
> + * @monitor: The monitor that the statistic data will be retrieved from.
> + * @resource: The name for resource name. 'llc_occupancy' for cache resource.
> + * "mbm_total_bytes" and "mbm_local_bytes" for memory bandwidth resource.
> + * @stats: Array of virResctrlMonitorStatsPtr for holding cache or memory
> + * bandwidth usage data.
> + * @nstats: A size_t pointer to hold the returned array length of @stats
> + *
> + * Get cache or memory bandwidth utilization information.
> + *
> + * Returns 0 on success, -1 on error.
> + */
> +static int
> +virResctrlMonitorGetStats(virResctrlMonitorPtr monitor,
> + const char *resource,
> + virResctrlMonitorStatsPtr *stats,
> + size_t *nstats)
> +{
> + int rv = -1;
> + int ret = -1;
> + DIR *dirp = NULL;
> + char *datapath = NULL;
> + struct dirent *ent = NULL;
> + virResctrlMonitorStatsPtr stat = NULL;
> +
> + if (!monitor) {
> + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> + _("Invalid resctrl monitor"));
> + return -1;
> + }
> +
> + if (virAsprintf(&datapath, "%s/mon_data", monitor->path) < 0)
> + return -1;
> +
> + if (virDirOpen(&dirp, datapath) < 0)
> + goto cleanup;
> +
> + *nstats = 0;
> + while (virDirRead(dirp, &ent, datapath) > 0) {
> + char *node_id = NULL;
> +
> + if (VIR_ALLOC(stat) < 0)
> + goto cleanup;
> +
> + /* Looking for directory that contains resource utilization
> + * information file. The directory name is arranged in format
> + * "mon_<node_name>_<node_id>". For example, "mon_L3_00" and
> + * "mon_L3_01" are two target directories for a two nodes system
> + * with resource utilization data file for each node respectively.
> + */
> + if (ent->d_type != DT_DIR)
> + continue;
> +
> + /* Looking for directory has a prefix 'mon_L' */
> + if (!(node_id = STRSKIP(ent->d_name, "mon_L")))
> + continue;
> +
> + /* Looking for directory has another '_' */
> + node_id = strchr(node_id, '_');
> + if (!node_id)
> + continue;
> +
> + /* Skip the character '_' */
> + if (!(node_id = STRSKIP(node_id, "_")))
> + continue;
> +
> + /* The node ID number should be here, parsing it. */
> + if (virStrToLong_uip(node_id, NULL, 0, &stat->id) < 0)
> + goto cleanup;
> +
> + rv = virFileReadValueUint(&stat->val, "%s/%s/%s", datapath,
> + ent->d_name, resource);
> + if (rv == -2) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("File '%s/%s/%s' does not exist."),
> + datapath, ent->d_name, resource);
> + }
> + if (rv < 0)
> + goto cleanup;
> +
> + if (VIR_APPEND_ELEMENT(*stats, *nstats, *stat) < 0)
> + goto cleanup;
> + }
> +
> + /* Sort in id's ascending order */
> + qsort(*stats, *nstats, sizeof(*stat), virResctrlMonitorStatsSorter);
Coverity notes that *stats could be NULL - if the above while loop gets
nothing...
> +
> + ret = 0;
> + cleanup:
> + VIR_FREE(datapath);
> + VIR_FREE(stat);
> + VIR_DIR_CLOSE(dirp);
> + return ret;
> +}
> +
> +
> +/*
> + * virResctrlMonitorGetCacheOccupancy
> + *
> + * @monitor: The monitor that the statistic data will be retrieved from.
> + * @caches: Array of virResctrlMonitorStatsPtr for receiving cache occupancy
> + * data. Caller is responsible to free this array.
> + * @ncaches: A size_t pointer to hold the returned array length of @caches
They're @stats and @nstats elsewhere, be consistent.
> + *
> + * Get cache or memory bandwidth utilization information.
> + *
> + * Returns 0 on success, -1 on error.
> + */
> +
> +int
> +virResctrlMonitorGetCacheOccupancy(virResctrlMonitorPtr monitor,
> + virResctrlMonitorStatsPtr *caches,
> + size_t *ncaches)
They're @stats and @nstats elsewhere, be consistent.
> +{
> + return virResctrlMonitorGetStats(monitor, "llc_occupancy",
> + caches, ncaches);
> +}
> diff --git a/src/util/virresctrl.h b/src/util/virresctrl.h
> index 8d8fdc2..004c40e 100644
> --- a/src/util/virresctrl.h
> +++ b/src/util/virresctrl.h
> @@ -191,6 +191,13 @@ virResctrlInfoGetMonitorPrefix(virResctrlInfoPtr resctrl,
> typedef struct _virResctrlMonitor virResctrlMonitor;
> typedef virResctrlMonitor *virResctrlMonitorPtr;
>
> +typedef struct _virResctrlMonitorStats virResctrlMonitorStats;
> +typedef virResctrlMonitorStats *virResctrlMonitorStatsPtr;
> +struct _virResctrlMonitorStats {
> + unsigned int id;
> + unsigned int val;
> +};
> +
> virResctrlMonitorPtr
> virResctrlMonitorNew(void);
>
> @@ -222,4 +229,9 @@ virResctrlMonitorRemove(virResctrlMonitorPtr monitor);
>
> bool
> virResctrlMonitorIsRunning(virResctrlMonitorPtr monitor);
> +
> +int
> +virResctrlMonitorGetCacheOccupancy(virResctrlMonitorPtr monitor,
> + virResctrlMonitorStatsPtr *caches,
> + size_t *ncaches);
They're @stats and @nstats elsewhere, be consistent.
> #endif /* __VIR_RESCTRL_H__ */
>
I'm sure there's more I'll pick up later, but you should have plenty for
now. As to splitting - I think some splitting could be done, I'll leave
it up to you... Lots of change across multiple areas - ask yourself -
can something be separated out?
John
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