Joao Martins wrote:
> Introduce support for domainMemoryStats API call, which
> consequently enables the use of `virsh dommemstat` command to
> query for memory statistics of a domain. We support
> the following statistics: balloon info, available and currently
> in use. swap-in, swap-out, major-faults, minor-faults require
> cooperation of the guest and thus currently not supported.
>
> We build on the data returned from libxl_domain_info and deliver
> it in the virDomainMemoryStat format.
>
> Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
> ---
> Changes since v1:
> - Cleanup properly after error fetching domain stats
> - Dispose libxl_dominfo after succesfull call to
> libxl_domain_info()
> - Bump version to 1.2.22
> ---
> src/libxl/libxl_driver.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 70 insertions(+)
>
> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
> index 50f6e34..f4fc7bc 100644
> --- a/src/libxl/libxl_driver.c
> +++ b/src/libxl/libxl_driver.c
> @@ -4749,6 +4749,75 @@ libxlDomainGetCPUStats(virDomainPtr dom,
> return ret;
> }
>
> +#define LIBXL_SET_MEMSTAT(TAG, VAL) \
> + if (i < nr_stats) { \
> + stats[i].tag = TAG; \
> + stats[i].val = VAL; \
> + i++; \
> + }
> +
> +static int
> +libxlDomainMemoryStats(virDomainPtr dom,
> + virDomainMemoryStatPtr stats,
> + unsigned int nr_stats,
> + unsigned int flags)
> +{
> + libxlDriverPrivatePtr driver = dom->conn->privateData;
> + libxlDriverConfigPtr cfg = libxlDriverConfigGet(driver);
> + virDomainObjPtr vm;
> + libxl_dominfo d_info;
> + unsigned mem, maxmem;
> + size_t i = 0;
> + int ret = -1;
> +
> + virCheckFlags(0, -1);
> +
> + if (!(vm = libxlDomObjFromDomain(dom)))
> + goto cleanup;
> +
> + if (virDomainMemoryStatsEnsureACL(dom->conn, vm->def) < 0)
> + goto cleanup;
> +
> + if (libxlDomainObjBeginJob(driver, vm, LIBXL_JOB_QUERY) < 0)
> + goto cleanup;
> +
> + if (!virDomainObjIsActive(vm)) {
> + virReportError(VIR_ERR_OPERATION_INVALID,
> + "%s", _("domain is not running"));
> + goto endjob;
> + }
> +
> + if (libxl_domain_info(cfg->ctx, &d_info, vm->def->id) != 0) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("libxl_domain_info failed for domain '%d'"),
> + vm->def->id);
> + goto endjob;
> + }
> + mem = d_info.current_memkb;
> + maxmem = d_info.max_memkb;
> +
> + LIBXL_SET_MEMSTAT(VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON, maxmem - mem);
Should this just be 'mem'? On a domain with
<memory unit='KiB'>1048576</memory>
<currentMemory unit='KiB'>1048576</currentMemory>
I see
# virsh dommemstat test
actual 1024
available 1049600
rss 1048576
The documentation for VIR_DOMAIN_MEMORY_STAT_ACTUAL_BALLOON only says "Current
balloon value (in KB)". I (perhaps incorrectly) interpret that as the amount of
memory currently assigned to the domain.
Also, I wonder if we should provide rss for Xen domains? I'm not sure it makes
much sense since Xen domains are more than just a process running on the host.
AFAIK, rss would always be set to d_info.current_memkb even if a domain was not
actually using all the memory.
Regards,
Jim
> + LIBXL_SET_MEMSTAT(VIR_DOMAIN_MEMORY_STAT_AVAILABLE, maxmem);
> + LIBXL_SET_MEMSTAT(VIR_DOMAIN_MEMORY_STAT_RSS, mem);
> +
> + ret = i;
> +
> + libxl_dominfo_dispose(&d_info);
> +
> + endjob:
> + if (!libxlDomainObjEndJob(driver, vm)) {
> + virObjectUnlock(vm);
> + vm = NULL;
> + }
> +
> + cleanup:
> + if (vm)
> + virObjectUnlock(vm);
> + return ret;
> +}
> +
> +#undef LIBXL_SET_MEMSTAT
> +
> static int
> libxlConnectDomainEventRegisterAny(virConnectPtr conn, virDomainPtr dom, int eventID,
> virConnectDomainEventGenericCallback callback,
> @@ -5342,6 +5411,7 @@ static virHypervisorDriver libxlHypervisorDriver = {
> #endif
> .nodeGetFreeMemory = libxlNodeGetFreeMemory, /* 0.9.0 */
> .nodeGetCellsFreeMemory = libxlNodeGetCellsFreeMemory, /* 1.1.1 */
> + .domainMemoryStats = libxlDomainMemoryStats, /* 1.2.22 */
> .domainGetCPUStats = libxlDomainGetCPUStats, /* 1.2.22 */
> .connectDomainEventRegister = libxlConnectDomainEventRegister, /* 0.9.0 */
> .connectDomainEventDeregister = libxlConnectDomainEventDeregister, /* 0.9.0 */
--
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