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| From: | Mark Kanda |
| Subject: | Re: [PATCH v4 1/3] qmp: Support for querying stats |
| Date: | Mon, 14 Mar 2022 12:28:02 -0500 |
| User-agent: | Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 |
Thank you Markus. On 3/11/2022 7:06 AM, Markus Armbruster wrote:
Mark Kanda <mark.kanda@oracle.com> writes:Introduce QMP support for querying stats. Provide a framework for adding new stats and support for the following commands: - query-stats Returns a list of all stats per target type (only VM and vCPU to start), with additional options for specifying stat names, vCPU qom paths, and providers. - query-stats-schemas Returns a list of stats included in each target type, with an option for specifying the provider. The framework provides a method to register callbacks for these QMP commands. The first use-case will be for fd-based KVM stats (in an upcoming patch). Examples (with fd-based KVM stats): - Query all VM stats: { "execute": "query-stats", "arguments" : { "target": "vm" } } { "return": { "vm": [ { "provider": "kvm", "stats": [ { "name": "max_mmu_page_hash_collisions", "value": 0 }, { "name": "max_mmu_rmap_size", "value": 0 }, { "name": "nx_lpage_splits", "value": 148 }, ... { "provider": "xyz", "stats": [ ... ... ] } } - Query all vCPU stats: { "execute": "query-stats", "arguments" : { "target": "vcpu" } } { "return": { "vcpus": [ { "path": "/machine/unattached/device[0]" "providers": [ { "provider": "kvm", "stats": [ { "name": "guest_mode", "value": 0 }, { "name": "directed_yield_successful", "value": 0 }, { "name": "directed_yield_attempted", "value": 106 }, ... { "provider": "xyz", "stats": [ ... ... { "path": "/machine/unattached/device[1]" "providers": [ { "provider": "kvm", "stats": [... ... } ] } } - Query 'exits' and 'l1d_flush' KVM stats, and 'somestat' from provider 'xyz' for vCPUs '/machine/unattached/device[2]' and '/machine/unattached/device[4]': { "execute": "query-stats", "arguments": { "target": "vcpu", "vcpus": [ "/machine/unattached/device[2]", "/machine/unattached/device[4]" ], "filters": [ { "provider": "kvm", "fields": [ "l1d_flush", "exits" ] }, { "provider": "xyz", "fields": [ "somestat" ] } ] } }Are the stats bulky enough to justfify the extra complexity of filtering?
If this was only for KVM, the complexity probably isn't worth it. However, the framework is intended to support future stats with new providers and targets (there has also been mention of moving existing stats to this framework). Without some sort of filtering, I think the payload could become unmanageable.
{ "return": { "vcpus": [ { "path": "/machine/unattached/device[2]" "providers": [ { "provider": "kvm", "stats": [ { "name": "l1d_flush", "value": 41213 }, { "name": "exits", "value": 74291 } ] }, { "provider": "xyz", "stats": [ ... ] } ] }, { "path": "/machine/unattached/device[4]" "providers": [ { "provider": "kvm", "stats": [ { "name": "l1d_flush", "value": 16132 }, { "name": "exits", "value": 57922 } ] }, { "provider": "xyz", "stats": [ ... ] } ] } ] } } - Query stats schemas: { "execute": "query-stats-schemas" } { "return": { "vcpu": [ { "provider": "kvm", "stats": [ { "name": "guest_mode", "unit": "none", "base": 10, "exponent": 0, "type": "instant" }, { "name": "directed_yield_successful", "unit": "none", "base": 10, "exponent": 0, "type": "cumulative" }, ... { "provider": "xyz", ... "vm": [ { "provider": "kvm", "stats": [ { "name": "max_mmu_page_hash_collisions", "unit": "none", "base": 10, "exponent": 0, "type": "peak" }, { "provider": "xyz", ...Can you give a use case for query-stats-schemas?
'query-stats-schemas' provide the the type details about each stat; such as the unit, base, etc. These details are not reported by 'query-stats' (only the stat name and raw values are returned).
Signed-off-by: Mark Kanda <mark.kanda@oracle.com> --- include/monitor/stats.h | 51 ++++++++ monitor/qmp-cmds.c | 219 +++++++++++++++++++++++++++++++++ qapi/meson.build | 1 + qapi/qapi-schema.json | 1 + qapi/stats.json | 259 ++++++++++++++++++++++++++++++++++++++++That's a lot of schema code. How much of it is for query-stats, and how much for query-stats-schemas?
It's roughly 60% query-stats, 40% query-stats-schemas.
How much of the query-stats part is for filtering?
I think filtering is about 40% of query-stats.
5 files changed, 531 insertions(+) create mode 100644 include/monitor/stats.h create mode 100644 qapi/stats.json[...]diff --git a/qapi/stats.json b/qapi/stats.json new file mode 100644 index 0000000000..ae5dc3ee2c --- /dev/null +++ b/qapi/stats.json @@ -0,0 +1,259 @@ +# -*- Mode: Python -*- +# vim: filetype=python +# +# Copyright (c) 2022 Oracle and/or its affiliates. +# +# This work is licensed under the terms of the GNU GPL, version 2 or later. +# See the COPYING file in the top-level directory. +# +# SPDX-License-Identifier: GPL-2.0-or-later + +## +# = Stats +## + +## +# @StatsType: +# +# Enumeration of stats typesWe commonly put a blank line between overview and arguments.
Will fix.
+# @cumulative: stat is cumulative; value can only increase. +# @instant: stat is instantaneous; value can increase or decrease. +# @peak: stat is the peak value; value can only increase. +# @linear-hist: stat is a linear histogram. +# @log-hist: stat is a logarithmic histogram. +# +# Since: 7.0 +## +{ 'enum' : 'StatsType', + 'data' : [ 'cumulative', 'instant', 'peak', 'linear-hist', 'log-hist' ] } + +## +# @StatsUnit: +# +# Enumeration of stats units +# @bytes: stat reported in bytes. +# @seconds: stat reported in seconds. +# @cycles: stat reported in clock cycles. +# @none: no unit for this stat. +# +# Since: 7.0 +## +{ 'enum' : 'StatsUnit', + 'data' : [ 'bytes', 'seconds', 'cycles', 'none' ] } + +## +# @StatsBase: +# +# Enumeration of stats base +# @pow10: scale is based on power of 10. +# @pow2: scale is based on power of 2. +# +# Since: 7.0 +## +{ 'enum' : 'StatsBase', + 'data' : [ 'pow10', 'pow2' ] } + +## +# @StatsProvider: +# +# Enumeration of stats providers. +# +# Since: 7.0 +## +{ 'enum': 'StatsProvider', + 'data': [ ] } + +## +# @StatsTarget: +# +# Enumeration of stats targets. +# @vm: stat is per vm. +# @vcpu: stat is per vcpu. +# +# Since: 7.0 +## +{ 'enum': 'StatsTarget', + 'data': [ 'vm', 'vcpu' ] } + +## +# @StatsRequest: +# +# Stats filter element. +# @provider: stat provider. +# @fields: list of stat names. +# +# Since: 7.0 +## +{ 'struct': 'StatsRequest', + 'data': { '*provider': 'StatsProvider', + '*fields': [ 'str' ] } } + +## +# @StatsRequestArray: +# +# @filters: filters for this request. +## +{ 'struct': 'StatsRequestArray', + 'data': { '*filters': [ 'StatsRequest' ] } } + +## +# @StatsVCPURequestArray: +# +# @vcpus: list of qom paths. +## +{ 'struct': 'StatsVCPURequestArray', + 'base': 'StatsRequestArray', + 'data': { '*vcpus': [ 'str' ] } } + +## +# @StatsFilter: +# +# Target specific filter. +# +# Since: 7.0 +## +{ 'union': 'StatsFilter', + 'base': { 'target': 'StatsTarget' }, + 'discriminator': 'target', + 'data': { 'vcpu': 'StatsVCPURequestArray', + 'vm': 'StatsRequestArray' } } + +## +# @StatsValueArray: +# +# @values: uint64 list. +# +# Since: 7.0 +## +{ 'struct': 'StatsValueArray', + 'data': { 'values' : [ 'uint64' ] } } + +## +# @StatsValue: +# +# @scalar: single uint64. +# @list: list of uint64. +# +# Since: 7.0 +## +{ 'alternate': 'StatsValue', + 'data': { 'scalar': 'uint64', + 'list': 'StatsValueArray' } }Any particular reason for wrapping the array in a struct?
Due to the limitation in the QAPI framework, I hit: ../qapi/stats.json:139: 'data' member 'list' cannot be an array I can look at adding support... Thanks/regards, -Mark
+ +## +# @Stats: +# +# @name: name of stat. +# @value: stat value. +# +# Since: 7.0 +## +{ 'struct': 'Stats', + 'data': { 'name': 'str', + 'value' : 'StatsValue' } } + +## +# @StatsResultsEntry: +# +# @provider: stat provider. +# @stats: list of stats. +# +# Since: 7.0 +## +{ 'struct': 'StatsResultsEntry', + 'data': { 'provider': 'StatsProvider', + 'stats': [ 'Stats' ] } } + +## +# @StatsResultsVCPUEntry: +# +# @path: vCPU qom path. +# @providers: per provider results. +# +# Since: 7.0 +## +{ 'struct': 'StatsResultsVCPUEntry', + 'data': { 'path': 'str', + 'providers': [ 'StatsResultsEntry' ] } } + +## +# @StatsResults: +# +# Target specific results. +# +# Since: 7.0 +## +{ 'struct': 'StatsResults', + 'data': { + '*vcpus': [ 'StatsResultsVCPUEntry' ], + '*vm': [ 'StatsResultsEntry' ] } } + +## +# @query-stats: +# +# data: @StatsFilter. +# Returns: @StatsResults. +# +# Since: 7.0 +## +{ 'command': 'query-stats', + 'data': 'StatsFilter', + 'boxed': true, + 'returns': 'StatsResults' } + +## +# @StatsSchemaValue: +# +# Individual stat schema. +# @name: stat name. +# @type: @StatType. +# @unit: @StatUnit. +# @base: @StatBase. +# @exponent: Used together with @base. +# @bucket-size: Used with linear-hist to report bucket size +# +# Since: 7.0 +## +{ 'struct': 'StatsSchemaValue', + 'data': { 'name': 'str', + 'type': 'StatsType', + 'unit': 'StatsUnit', + 'base': 'StatsBase', + 'exponent': 'int16', + '*bucket-size': 'uint32' } } + +## +# @StatsSchemaProvider: +# +# @provider: @StatsProvider. +# @stats: list of stats. +# +# Since: 7.0 +## +{ 'struct': 'StatsSchemaProvider', + 'data': { 'provider': 'StatsProvider', + 'stats': [ 'StatsSchemaValue' ] } } + +## +# @StatsSchemaResults: +# +# @vm: vm stats schemas. +# @vcpu: vcpu stats schemas. +# +# Since: 7.0 +## +{ 'struct': 'StatsSchemaResults', + 'data': { '*vm': [ 'StatsSchemaProvider' ], + '*vcpu': [ 'StatsSchemaProvider' ] } } + +## +# @query-stats-schemas: +# +# Query Stats schemas. +# Returns @StatsSchemaResult. +# +# Since: 7.0 +## +{ 'command': 'query-stats-schemas', + 'data': { '*provider': 'StatsProvider' }, + 'returns': 'StatsSchemaResults' }
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