diff options
| -rw-r--r-- | include/libvirt/libvirt.h.in | 14 | ||||
| -rwxr-xr-x | python/generator.py | 1 | ||||
| -rw-r--r-- | src/driver.h | 8 | ||||
| -rw-r--r-- | src/libvirt.c | 128 | ||||
| -rw-r--r-- | src/libvirt_public.syms | 3 |
5 files changed, 153 insertions, 1 deletions
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index edc9d708b..f55fac392 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -3811,6 +3811,20 @@ int virConnectSetKeepAlive(virConnectPtr conn, int interval, unsigned int count); +/* Collecting CPU statistics */ + +/** + * VIR_DOMAIN_CPU_STATS_CPUTIME: + * cpu usage in nanoseconds, as a ullong + */ +#define VIR_DOMAIN_CPU_STATS_CPUTIME "cpu_time" + +int virDomainGetCPUStats(virDomainPtr domain, + virTypedParameterPtr params, + unsigned int nparams, + int start_cpu, + unsigned int ncpus, + unsigned int flags); #ifdef __cplusplus } #endif diff --git a/python/generator.py b/python/generator.py index 791b267a5..6f813ae0d 100755 --- a/python/generator.py +++ b/python/generator.py @@ -423,6 +423,7 @@ skip_impl = ( 'virDomainGetBlockIoTune', 'virDomainSetInterfaceParameters', 'virDomainGetInterfaceParameters', + 'virDomainGetCPUStats' # not implemented now. ) qemu_skip_impl = ( diff --git a/src/driver.h b/src/driver.h index faeff34cd..ba7dbc49b 100644 --- a/src/driver.h +++ b/src/driver.h @@ -802,6 +802,13 @@ typedef int (*virDrvDomainShutdownFlags)(virDomainPtr domain, unsigned int flags); +typedef int + (*virDrvDomainGetCPUStats)(virDomainPtr domain, + virTypedParameterPtr params, + unsigned int nparams, + int start_cpu, + unsigned int ncpus, + unsigned int flags); /** * _virDriver: @@ -973,6 +980,7 @@ struct _virDriver { virDrvNodeSuspendForDuration nodeSuspendForDuration; virDrvDomainSetBlockIoTune domainSetBlockIoTune; virDrvDomainGetBlockIoTune domainGetBlockIoTune; + virDrvDomainGetCPUStats domainGetCPUStats; }; typedef int diff --git a/src/libvirt.c b/src/libvirt.c index 812bc0ff6..9de64fd4b 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -18151,3 +18151,131 @@ error: virDispatchError(dom->conn); return -1; } + +/** + * virDomainGetCPUStats: + * @domain: domain to query + * @params: array to populate on output + * @nparams: number of parameters per cpu + * @start_cpu: which cpu to start with, or -1 for summary + * @ncpus: how many cpus to query + * @flags: extra flags; not used yet, so callers should always pass 0 + * + * Get statistics relating to CPU usage attributable to a single + * domain (in contrast to the statistics returned by + * virNodeGetCPUStats() for all processes on the host). @dom + * must be running (an inactive domain has no attributable cpu + * usage). On input, @params must contain at least @nparams * @ncpus + * entries, allocated by the caller. + * + * If @start_cpu is -1, then @ncpus must be 1, and the returned + * results reflect the statistics attributable to the entire + * domain (such as user and system time for the process as a + * whole). Otherwise, @start_cpu represents which cpu to start + * with, and @ncpus represents how many consecutive processors to + * query, with statistics attributable per processor (such as + * per-cpu usage). + * + * The remote driver imposes a limit of 128 @ncpus and 16 @nparams; + * the number of parameters per cpu should not exceed 16, but if you + * have a host with more than 128 CPUs, your program should split + * the request into multiple calls. + * + * As special cases, if @params is NULL and @nparams is 0 and + * @ncpus is 1, and the return value will be how many + * statistics are available for the given @start_cpu. This number + * may be different for @start_cpu of -1 than for any non-negative + * value, but will be the same for all non-negative @start_cpu. + * Likewise, if @params is NULL and @nparams is 0 and @ncpus is 0, + * the number of cpus available to query is returned. From the + * host perspective, this would typically match the cpus member + * of virNodeGetInfo(), but might be less due to host cpu hotplug. + * + * For now, @flags is unused, and the statistics all relate to the + * usage from the host perspective. It is possible that a future + * version will support a flag that queries the cpu usage from the + * guest's perspective, where the maximum cpu to query would be + * related to virDomainGetVcpusFlags() rather than virNodeGetInfo(). + * An individual guest vcpu cannot be reliably mapped back to a + * specific host cpu unless a single-processor vcpu pinning was used, + * but when @start_cpu is -1, any difference in usage between a host + * and guest perspective would serve as a measure of hypervisor overhead. + * + * Typical use sequence is below. + * + * getting total stats: set start_cpu as -1, ncpus 1 + * virDomainGetCPUStats(dom, NULL, 0, -1, 1, 0) => nparams + * params = calloc(nparams, sizeof (virTypedParameter)) + * virDomainGetCPUStats(dom, params, nparams, -1, 1, 0) => total stats. + * + * getting per-cpu stats: + * virDomainGetCPUStats(dom, NULL, 0, 0, 0, 0) => ncpus + * virDomainGetCPUStats(dom, NULL, 0, 0, 1, 0) => nparams + * params = calloc(ncpus * nparams, sizeof (virTypedParameter)) + * virDomainGetCPUStats(dom, params, nparams, 0, ncpus, 0) => per-cpu stats + * + * Returns -1 on failure, or the number of statistics that were + * populated per cpu on success (this will be less than the total + * number of populated @params, unless @ncpus was 1; and may be + * less than @nparams). The populated parameters start at each + * stride of @nparams, which means the results may be discontiguous; + * any unpopulated parameters will be zeroed on success. The caller + * is responsible for freeing any returned string parameters. + */ +int virDomainGetCPUStats(virDomainPtr domain, + virTypedParameterPtr params, + unsigned int nparams, + int start_cpu, + unsigned int ncpus, + unsigned int flags) +{ + virConnectPtr conn; + + VIR_DOMAIN_DEBUG(domain, + "params=%p, nparams=%d, start_cpu=%d, ncpus=%u, flags=%x", + params, nparams, start_cpu, ncpus, flags); + virResetLastError(); + + if (!VIR_IS_CONNECTED_DOMAIN(domain)) { + virLibDomainError(VIR_ERR_INVALID_DOMAIN, __FUNCTION__); + virDispatchError(NULL); + return -1; + } + + conn = domain->conn; + /* Special cases: + * start_cpu must be non-negative, or else -1 + * if start_cpu is -1, ncpus must be 1 + * params == NULL must match nparams == 0 + * ncpus must be non-zero unless params == NULL + */ + if (start_cpu < -1 || + (start_cpu == -1 && ncpus != 1) || + ((params == NULL) != (nparams == 0)) || + (ncpus == 0 && params != NULL)) { + virLibDomainError(VIR_ERR_INVALID_ARG, __FUNCTION__); + goto error; + } + + /* remote protocol doesn't welcome big args in one shot */ + if ((nparams > 16) || (ncpus > 128)) { + virLibDomainError(VIR_ERR_INVALID_ARG, __FUNCTION__); + goto error; + } + + if (conn->driver->domainGetCPUStats) { + int ret; + + ret = conn->driver->domainGetCPUStats(domain, params, nparams, + start_cpu, ncpus, flags); + if (ret < 0) + goto error; + return ret; + } + + virLibDomainError(VIR_ERR_NO_SUPPORT, __FUNCTION__); + +error: + virDispatchError(domain->conn); + return -1; +} diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms index 7371c5c11..1c4e0a3aa 100644 --- a/src/libvirt_public.syms +++ b/src/libvirt_public.syms @@ -518,10 +518,11 @@ LIBVIRT_0.9.9 { LIBVIRT_0.9.10 { global: + virDomainGetCPUStats; + virDomainPMSuspendForDuration; virDomainShutdownFlags; virStorageVolResize; virStorageVolWipePattern; - virDomainPMSuspendForDuration; } LIBVIRT_0.9.9; # .... define new API here using predicted next version number .... |