On Mon, Jul 4, 2022 at 11:28 AM Marc-André Lureau <
marcandre.lur...@gmail.com> wrote:
> Hi
>
> On Mon, Jul 4, 2022 at 6:42 AM zhenwei pi <pizhen...@bytedance.com> wrote:
>
>> A vCPU thread always reaches 100% utilization when:
>> - guest uses idle=poll
>> - disable HLT vm-exit
>> - enable MWAIT
>>
>> Add new guest agent command 'guest-get-cpustats' to get guest CPU
>> statistics, we can know the guest workload and how busy the CPU is.
>>
>> Signed-off-by: zhenwei pi <pizhen...@bytedance.com>
>> ---
>> qga/commands-posix.c | 89 ++++++++++++++++++++++++++++++++++++++++++++
>> qga/commands-win32.c | 6 +++
>> qga/qapi-schema.json | 81 ++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 176 insertions(+)
>>
>> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
>> index 0469dc409d..e51f4c8f03 100644
>> --- a/qga/commands-posix.c
>> +++ b/qga/commands-posix.c
>> @@ -2893,6 +2893,90 @@ GuestDiskStatsInfoList
>> *qmp_guest_get_diskstats(Error **errp)
>> return guest_get_diskstats(errp);
>> }
>>
>> +GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
>> +{
>> + GuestCpuStatsList *head = NULL, **tail = &head;
>> + const char *cpustats = "/proc/stat";
>> + int clk_tck = sysconf(_SC_CLK_TCK);
>> + FILE *fp;
>> + size_t n;
>> + char *line = NULL;
>> +
>> + fp = fopen(cpustats, "r");
>> + if (fp == NULL) {
>> + error_setg_errno(errp, errno, "open(\"%s\")", cpustats);
>> + return NULL;
>> + }
>> +
>> + while (getline(&line, &n, fp) != -1) {
>> + GuestCpuStats *cpustat = NULL;
>> + GuestLinuxCpuStats *linuxcpustat;
>> + int i;
>> + unsigned long user, system, idle, iowait, irq, softirq, steal,
>> guest;
>> + unsigned long nice, guest_nice;
>> + char name[64];
>> +
>> + i = sscanf(line, "%s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu",
>> + name, &user, &nice, &system, &idle, &iowait, &irq,
>> &softirq,
>> + &steal, &guest, &guest_nice);
>> +
>> + /* drop "cpu 1 2 3 ...", get "cpuX 1 2 3 ..." only */
>> + if ((i == EOF) || strncmp(name, "cpu", 3) || (name[3] == '\0')) {
>> + continue;
>> + }
>> +
>> + if (i < 5) {
>> + slog("Parsing cpu stat from %s failed, see \"man proc\"",
>> cpustats);
>> + break;
>> + }
>> +
>> + cpustat = g_new0(GuestCpuStats, 1);
>> + cpustat->type = GUEST_OS_TYPE_LINUXOS;
>> +
>> + linuxcpustat = &cpustat->u.linuxos;
>> + linuxcpustat->cpu = atoi(&name[3]);
>> + linuxcpustat->user = user * 1000 / clk_tck;
>> + linuxcpustat->nice = nice * 1000 / clk_tck;
>> + linuxcpustat->system = system * 1000 / clk_tck;
>> + linuxcpustat->idle = idle * 1000 / clk_tck;
>> +
>> + if (i > 5) {
>> + linuxcpustat->has_iowait = true;
>> + linuxcpustat->iowait = iowait * 1000 / clk_tck;
>> + }
>> +
>> + if (i > 6) {
>> + linuxcpustat->has_irq = true;
>> + linuxcpustat->irq = irq * 1000 / clk_tck;
>> + linuxcpustat->has_softirq = true;
>> + linuxcpustat->softirq = softirq * 1000 / clk_tck;
>> + }
>> +
>> + if (i > 8) {
>> + linuxcpustat->has_steal = true;
>> + linuxcpustat->steal = steal * 1000 / clk_tck;
>> + }
>> +
>> + if (i > 9) {
>> + linuxcpustat->has_guest = true;
>> + linuxcpustat->guest = guest * 1000 / clk_tck;
>> + }
>> +
>> + if (i > 10) {
>> + linuxcpustat->has_guest = true;
>> + linuxcpustat->guest = guest * 1000 / clk_tck;
>> + linuxcpustat->has_guestnice = true;
>> + linuxcpustat->guestnice = guest_nice * 1000 / clk_tck;
>> + }
>> +
>> + QAPI_LIST_APPEND(tail, cpustat);
>> + }
>> +
>> + free(line);
>> + fclose(fp);
>> + return head;
>> +}
>> +
>> #else /* defined(__linux__) */
>>
>> void qmp_guest_suspend_disk(Error **errp)
>> @@ -3247,6 +3331,11 @@ GuestDiskStatsInfoList
>> *qmp_guest_get_diskstats(Error **errp)
>> return NULL;
>> }
>>
>> +GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
>> +{
>> + error_setg(errp, QERR_UNSUPPORTED);
>> + return NULL;
>> +}
>>
>> #endif /* CONFIG_FSFREEZE */
>>
>> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
>> index 36f94c0f9c..7ed7664715 100644
>> --- a/qga/commands-win32.c
>> +++ b/qga/commands-win32.c
>> @@ -2543,3 +2543,9 @@ GuestDiskStatsInfoList
>> *qmp_guest_get_diskstats(Error **errp)
>> error_setg(errp, QERR_UNSUPPORTED);
>> return NULL;
>> }
>> +
>> +GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
>> +{
>> + error_setg(errp, QERR_UNSUPPORTED);
>> + return NULL;
>> +}
>> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
>> index 9fa20e791b..3b795222e9 100644
>> --- a/qga/qapi-schema.json
>> +++ b/qga/qapi-schema.json
>> @@ -1576,3 +1576,84 @@
>> { 'command': 'guest-get-diskstats',
>> 'returns': ['GuestDiskStatsInfo']
>> }
>> +
>> +##
>> +# @GuestOsType:
>> +#
>> +# An enumeration of OS type
>> +#
>> +# Since: 7.1
>> +##
>> +{ 'enum': 'GuestOsType',
>> + 'data': [ 'linuxos', 'windowsos' ] }
>>
>
> I would rather keep this enum specific to GuestCpuStats,
> "GuestLinuxCpuStatsType"?
>
Oops, I meant "GuestCpuStatsType"
> I would also drop the "os" suffix
>
> +
>> +
>> +##
>> +# @GuestLinuxCpuStats:
>> +#
>> +# CPU statistics of Linux
>> +#
>> +# @cpu: CPU index in guest OS
>> +#
>> +# @user: Time spent in user mode
>> +#
>> +# @nice: Time spent in user mode with low priority (nice)
>> +#
>> +# @system: Time spent in system mode
>> +#
>> +# @idle: Time spent in the idle task
>> +#
>> +# @iowait: Time waiting for I/O to complete (since Linux 2.5.41)
>> +#
>> +# @irq: Time servicing interrupts (since Linux 2.6.0-test4)
>> +#
>> +# @softirq: Time servicing softirqs (since Linux 2.6.0-test4)
>> +#
>> +# @steal: Stolen time by host (since Linux 2.6.11)
>> +#
>> +# @guest: ime spent running a virtual CPU for guest operating systems
>> under
>> +# the control of the Linux kernel (since Linux 2.6.24)
>> +#
>> +# @guestnice: Time spent running a niced guest (since Linux 2.6.33)
>> +#
>> +# Since: 7.1
>> +##
>> +{ 'struct': 'GuestLinuxCpuStats',
>> + 'data': {'cpu': 'int',
>> + 'user': 'uint64',
>> + 'nice': 'uint64',
>> + 'system': 'uint64',
>> + 'idle': 'uint64',
>> + '*iowait': 'uint64',
>> + '*irq': 'uint64',
>> + '*softirq': 'uint64',
>> + '*steal': 'uint64',
>> + '*guest': 'uint64',
>> + '*guestnice': 'uint64'
>> + } }
>> +
>> +##
>> +# @GuestCpuStats:
>> +#
>> +# Get statistics of each CPU in millisecond.
>> +#
>> +# - @linux: Linux style CPU statistics
>> +#
>> +# Since: 7.1
>> +##
>> +{ 'union': 'GuestCpuStats',
>> + 'base': { 'type': 'GuestOsType' },
>> + 'discriminator': 'type',
>> + 'data': { 'linuxos': 'GuestLinuxCpuStats' } }
>> +
>> +##
>> +# @guest-get-cpustats:
>> +#
>> +# Retrieve information about CPU stats.
>> +# Returns: List of CPU stats of guest.
>> +#
>> +# Since: 7.1
>> +##
>> +{ 'command': 'guest-get-cpustats',
>> + 'returns': ['GuestCpuStats']
>> +}
>> --
>> 2.20.1
>>
>>
>>
> Looks good to me otherwise.
> thanks
>
> --
> Marc-André Lureau
>
--
Marc-André Lureau
